@article {dulong_exopolysaccharide_2024, title = {Exopolysaccharide from marine microalgae belonging to the \textit{Glossomastix genus: fragile gel behavior and suspension stability}, journal = {Bioengineered}, volume = {15}, number = {1}, year = {2024}, note = {Publisher: Taylor \& Francis _eprint: https://doi.org/10.1080/21655979.2023.2296257}, month = {dec}, pages = {2296257}, abstract = {With the aim to find new polysaccharides of rheological interest with innovated properties, rhamnofucans produced as exopolysaccharides (EPS) in a photobioreactor (PBR) and an airlift bioreactor (ABR) by the marine microalgae Glossomastix sp. RCC3707 and RCC3688 were fully studied. Chemical characterizations have been conducted (UHPLC {\textendash} MS HR). Analyses by size-exclusion chromatography (SEC) coupled online with a multiangle light scattering detector (MALS) and a differential refractive index detector showed the presence of large structures with molar masses higher than 106 g.mol-1. The rheological studies of these EPS solutions, conducted at different concentrations and salinities, have evidenced interesting and rare behavior characteristic of weak and fragile hydrogels i.e. gel behavior with very low elastic moduli (between 10-2 and 10 Pa) and yield stresses (between 10-2 and 2 Pa) according to the EPS source, concentration, and salinity. These results were confirmed by diffusing wave spectroscopy. Finally, as one of potential application, solutions of EPS from Glossomastix sp. have evidenced very good properties as anti-settling stabilizers, using microcrystalline cellulose particles as model, studied by multiple light scattering (MLS) with utilization in cosmetic or food industry. Compared to alginate solution with same viscosity for which sedimentation is observed over few hours, microalgae EPS leads to a stable suspension over few days.}, keywords = {fragile gel, Glossomastix, Microalgae, Polysaccharide, RCC3688, RCC3707, stabilizer}, issn = {2165-5979}, doi = {10.1080/21655979.2023.2296257}, url = {https://doi.org/10.1080/21655979.2023.2296257}, author = {Dulong, Virginie and Rihouey, Christophe and Gaignard, Cl{\'e}ment and Bridiau, Nicolas and Gourvil, Priscilla and Laroche, C{\'e}line and Pierre, Guillaume and Varacavoudin, Tony and Probert, Ian and Maugard, Thierry and Michaud, Philippe and Picton, Luc and Le Cerf, Didier} } @article {wang_meta-analysis_2024, title = {Meta-analysis reveals responses of coccolithophores and diatoms to warming}, journal = {Marine Environmental Research}, volume = {193}, year = {2024}, pages = {106275}, abstract = {A meta-analysis was conducted to explore the effects of warming on the physiological processes of coccolitho- phores and diatoms by synthesizing a large number of published literatures. A total of 154 studies consisting 301 experiments were synthesized in this study. Under a projected temperature increase of 3{\textendash}5 {\textopenbullet}C by IPCC AR6 at the end of this century, our results suggest that the growth and photosynthetic rate of coccolithophores were significantly enhanced by the rising temperature, while the calcification of coccolithophores was only slightly promoted. Warming also had significantly positive effects on the growth but not photosynthesis of diatoms. In comparison, the effect size of warming on the growth rate of coccolithophores was larger than that of diatoms. However, there was no significant effect of warming on either the ratio of particulate inorganic carbon to par- ticulate organic carbon (PIC:POC) of coccolithophores or the ratio of biogenic silica to carbon (BSi:C) of diatoms. Furthermore, the results reveal latitudinal and size-specific patterns of the effect sizes of warming. For diatoms, the effects of warming on growth were more prominent in high latitudes, specifically for the Southern Hemi- sphere species. In addition, the effect size of warming on the small-sized diatoms was larger than that of the large-sized diatoms. For coccolithophores, the growth of the Southern Hemisphere temperate strains was significantly promoted by warming. Overall, the results based on the meta-analysis indicate that the projected warming of the end of this century will be more favor to the growth of coccolithophores than that of diatoms, thus potentially affect the competitive advantages of coccolithophores over diatoms; while the mid-to high latitude species/strains of both coccolithophores and diatoms will benefit more than their counterparts in the lower latitudes. Therefore, this study offers novel insights into predicting both the inter- and intra-group competitive advantages of diatoms and coccolithophores under the future warming climate change scenario.}, keywords = {rcc1238}, issn = {01411136}, doi = {10.1016/j.marenvres.2023.106275}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0141113623004038}, author = {Wang, Jiawei and Zeng, Cong and Feng, Yuanyuan} } @article {azizah_2-homoectoine_2023, title = {2-Homoectoine: An Additional Member of the Ectoine Family from Phyto- and Bacterioplankton Involved in Osmoadaptation}, journal = {Journal of Natural Products}, year = {2023}, note = {Publisher: American Chemical Society}, month = {dec}, abstract = {Ectoine is a central osmolyte in marine plankton due to its excellent cytoprotective traits and its multifunctional roles supporting the survival of microalgae and bacteria under unfavorable environmental conditions. The protective effect of ectoine toward several kinds of stresses stirred interest in biotechnology, pharmacy, and other fields including cosmetics. Also, its hydroxylated derivative, 5-hydroxyectoine, exhibits functions similar to ectoine. Here we introduce a molecular networking-based approach to expand the family of ectoine derivatives from phyto- and bacterioplankton. A ZIC-HILIC separation protocol coupled with HRMS/MS-based molecular networking allowed us to identify the new ectoine derivative 1,4,5,6-tetrahydro-2-ethyl-4-pyrimidinecarboxylic acid, or 2-homoectoine (1). 1 is found in many algae including dinoflagellates, chlorophytes, and haptophytes. In axenic strains, the content of 1 is substantially lower. In accordance, we found that marine bacteria are prolific producers of the compound as well. This suggests that the microalgae with their associated microbiome have to be considered as sources of the compound. Increasing concentrations of the compound under high salinity suggest a role as a protectant against osmotic stress.}, keywords = {RCC131, RCC3579}, issn = {0163-3864}, doi = {10.1021/acs.jnatprod.3c00766}, url = {https://doi.org/10.1021/acs.jnatprod.3c00766}, author = {Azizah, Muhaiminatul and Pohnert, Georg} } @mastersthesis {wink_application_2023, title = {Application of Flow Cytometry and Membrane Inlet Mass Spectrometry as Tools to Assess Dimethyl Sulfide Produced in Emiliania huxleyi (CHC108) Cultures}, year = {2023}, school = {University of Galway}, type = {masters}, address = {Galway}, abstract = {Dimethyl sulphide (DMS) is a key component in the global sulphur cycle with emphasized significance in areas away from anthropogenic sources. Phytoplankton produce DMS when under stress as a defence mechanism from abiotic and biotic influences such as high wind stress and grazing. E. huxleyi was used as the phytoplankton of choice because of the cosmopolitan nature of the species along with the more robust nature of the coccolith. DMS has a high diffusion rate in the atmosphere so immediately monitoring the levels in the water column has proven difficult especially when looking at continuous input flux. In this study, membrane inlet mass spectrometry was used to monitor DMS flux over varying periods of time along with a possible variation of DMS under Mass 47 which excludes one of the methyl groups under different stressors. This continuous observation allowed for the observation in minute changes over longer periods of time rather than using the snapshot method which looks at chemical concentrations at singular points in time. This novel technique can give insights to the response times of the phytoplankton to the changing environment in real time. The added stressors to the water column did result in an increase of DMS but the lag time to the addition and the visible increase in DMS did not follow the expected trend. Of the parameters tested here, the most likely to initiate DMS production is heavy metal loading and water column acidification}, keywords = {RCC3852, ⛔ No DOI found}, author = {Wink, Adelaide Lavenant} } @article {bouquet_artificial_2023, title = {Artificial Substrates Coupled with qPCR (AS-qPCR) Assay for the Detection of the Toxic Benthopelagic Dinoflagellate Vulcanodinium rugosum}, journal = {Toxins}, volume = {15}, number = {3}, year = {2023}, note = {Number: 3 Publisher: Multidisciplinary Digital Publishing Institute}, month = {mar}, pages = {217}, abstract = {Vulcanodinium rugosum is an emerging benthopelagic neuro-toxic dinoflagellate species responsible for seasonal Pinnatoxins and Portimines contaminations of shellfish and marine animals. This species is challenging to detect in the environment, as it is present in low abundance and difficult to be identified using light microscopy. In this work, we developed a method using artificial substrates coupled with qPCR (AS-qPCR) to detect V. rugosum in a marine environment. This sensitive, specific and easy-to-standardize alternative to current techniques does not require specialized expertise in taxonomy. After determining the limits and specificity of the qPCR, we searched for the presence of V. rugosum in four French Mediterranean lagoons using artificial substrates collected every two weeks for one year. The AS-qPCR method revealed its occurrences in summer 2021 in every studied lagoon and detected cells in more samples than light microscopy. As V. rugosum development induces shellfish contamination even at low microalga densities, the AS-qPCR method is accurate and relevant for monitoring V. rugosum in a marine environment.}, keywords = {artificial substrate, benthopelagic, detection, PCR, RCC6328, RCC6338, RCC6344, RCC6548, RCC6550, toxins, \textitVulcanodinium rugosum}, issn = {2072-6651}, doi = {10.3390/toxins15030217}, url = {https://www.mdpi.com/2072-6651/15/3/217}, author = {Bouquet, Aur{\'e}lien and Felix, Christine and Masseret, Estelle and Reymond, Coralie and Abadie, Eric and Laabir, Mohamed and Rolland, Jean Luc} } @article {das_assessing_2023, title = {Assessing indicators of arsenic toxicity using variable fluorescence in a commercially valuable microalgae: physiological and toxicological aspects}, journal = {Journal of Hazardous Materials}, year = {2023}, month = {mar}, pages = {131215}, abstract = {Indicators signaling Arsenic (As) stress through physiology of microalgae using non-destructive methods like variable fluorescence are rare but requisite. This study reports stress markers indicating arsenic (As) toxicity (in two concentrations 11.25{\textmu}g/L and 22.5{\textmu}g/L compared to a control) exposed to a microalga (Diacronema lutheri), using fast repetition rate fluorometry (FRRf). Growth and physiological parameters such as cell density, chl a and the maximum quantum yield Fv/Fm showed coherence and impeded after the exponential phase (day 9 - day 12) in As treatments compared to the control (p < 0.05). On contrary photo-physiological constants were elevated showing higher optical (aLHII) and functional [Sigma (σPSII)] absorption cross-section for the As treatments (p < 0.05) further implying the lack of biomass production yet an increase in light absorption. In addition, As exposure increased the energy dissipation by heat (NPQ-NSV) showing a strong relationship with the de-epoxidation ratio (DR) involving photoprotective pigments. Total As bioaccumulation by D. lutheri showed a strong affinity with Fe adsorption throughout the algal growth curve. This study suggests some prompt photo-physiological proxies signaling As contamination and endorsing its usefulness in risk assessments, given the high toxicity and ubiquitous presence of As in the ecosystem.}, keywords = {Arsenic bioaccumulation, de-epoxidation ratio (DR), Optical absorption cross section, pigment concentrations, RCC1537}, issn = {0304-3894}, doi = {10.1016/j.jhazmat.2023.131215}, url = {https://www.sciencedirect.com/science/article/pii/S0304389423004971}, author = {Das, Shagnika and Lizon, Fabrice and Gevaert, Fran{\c c}ois and Bialais, Capucine and Duong, Gwendoline and Ouddane, Baghdad and Souissi, Sami} } @article {strauss_bay_2023, title = {The Bay of Bengal exposes abundant photosynthetic picoplankton and newfound diversity along salinity-driven gradients}, journal = {Environmental Microbiology}, year = {2023}, abstract = {The Bay of Bengal (BoB) is a 2,600,000 km2 expanse in the Indian Ocean upon which many humans rely. However, the primary producers underpinning food chains here remain poorly characterized. We examined phytoplankton abundance and diversity along strong BoB latitudinal and vertical salinity gradients-which have low temperature variation (27-29{\textdegree}C) between the surface and subsurface chlorophyll maximum (SCM). In surface waters, Prochlorococcus averaged 11.7 {\textpm} 4.4 {\texttimes} 104 cells ml-1 , predominantly HLII, whereas LLII and {\textquoteright}rare{\textquoteright} ecotypes, HLVI and LLVII, dominated in the SCM. Synechococcus averaged 8.4 {\textpm} 2.3 {\texttimes} 104 cells ml-1 in the surface, declined rapidly with depth, and population structure of dominant Clade II differed between surface and SCM; Clade X was notable at both depths. Across all sites, Ostreococcus Clade OII dominated SCM eukaryotes whereas communities differentiated strongly moving from Arabian Sea-influenced high salinity (southerly; prasinophytes) to freshwater-influenced low salinity (northerly; stramenopiles, specifically, diatoms, pelagophytes, and dictyochophytes, plus the prasinophyte Micromonas) surface waters. Eukaryotic phytoplankton peaked in the south (1.9 {\texttimes} 104 cells ml-1 , surface) where a novel Ostreococcus was revealed, named here Ostreococcus bengalensis. We expose dominance of a single picoeukaryote and hitherto {\textquoteright}rare{\textquoteright} picocyanobacteria at depth in this complex ecosystem where studies suggest picoplankton are replacing larger phytoplankton due to climate change.}, keywords = {RCC393, RCC809}, issn = {1462-2920}, doi = {10.1111/1462-2920.16431}, author = {Strauss, Jan and Choi, Chang Jae and Grone, Jonathan and Wittmers, Fabian and Jimenez, Valeria and Makareviciute-Fichtner, Kriste and Bachy, Charles and Jaeger, Gualtiero Spiro and Poirier, Camille and Eckmann, Charlotte and Spezzano, Rachele and L{\"o}scher, Carolin R. and Sarma, V. V. S. S. and Mahadevan, Amala and Worden, Alexandra Z.} } @article {letscher_biodiversity_2023, title = {Biodiversity and stoichiometric plasticity increase pico-phytoplankton contributions to marine net primary productivity and the biological pump}, journal = {Global Biogeochemical Cycles}, volume = {n/a}, number = {n/a}, year = {2023}, note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023GB007756}, pages = {e2023GB007756}, abstract = {Earth System Models generally predict increasing upper ocean stratification from 21st century warming, which will cause a decrease in the vertical nutrient flux forcing declines in marine net primary productivity (NPP) and carbon export. Recent advances in quantifying marine ecosystem carbon to nutrient stoichiometry have identified large latitudinal and biome variability, with low-latitude oligotrophic systems harboring pico-sized phytoplankton exhibiting large phosphorus to carbon cellular plasticity. Climate forced changes in nutrient flux stoichiometry and phytoplankton community composition is thus likely to alter the ocean{\textquoteright}s biogeochemical response and feedback with the carbon-climate system. We have added three pico-phytoplankton functional types within the Biogeochemical Elemental Cycling component of the Community Earth System Model while incorporating variable cellular phosphorus to carbon stoichiometry for all represented phytoplankton types. The model simulates Prochlorococcus and Synechococcus populations that dominate the productivity and sinking carbon export of the tropical and subtropical ocean, and pico-eukaryote populations that contribute significantly to productivity and export within the subtropical to mid-latitude transition zone, with the western subtropical regions of each basin supporting the most P-poor stoichiometries. Subtropical gyre recirculation regions along the poleward flanks of surface western boundary currents are identified as regional hotspots of enhanced carbon export exhibiting C-rich/P-poor stoichiometry, preferentially inhabited by pico-eukaryotes and diatoms. Collectively, pico-phytoplankton contribute \~{}58\% of global NPP and \~{}46\% of global particulate organic carbon export below 100 meters through direct and ecosystem processing pathways. Biodiversity and cellular nutrient plasticity in marine pico-phytoplankton combine to increase their contributions to ocean productivity and the biological carbon pump. This article is protected by copyright. All rights reserved.}, keywords = {carbon export, net primary productivity, pico-phytoplankton, rcc162, rcc1677, rcc212, rcc289, rcc296, rcc30, rcc438, variable C:P}, issn = {1944-9224}, doi = {10.1029/2023GB007756}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023GB007756}, author = {Letscher, Robert T. and Moore, J. Keith and Martiny, Adam C. and Lomas, Michael W.} } @article {churakova_biogenic_2023, title = {Biogenic silica accumulation in picoeukaryotes: Novel players in the marine silica cycle}, journal = {Environmental Microbiology Reports}, volume = {n/a}, number = {n/a}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/1758-2229.13144}, abstract = {It is well known that the biological control of oceanic silica cycling is dominated by diatoms, with sponges and radiolarians playing additional roles. Recent studies have revealed that some smaller marine organisms (e.g. the picocyanobacterium Synechococcus) also take up silicic acid (dissolved silica, dSi) and accumulate silica, despite not exhibiting silicon dependent cellular structures. Here, we show biogenic silica (bSi) accumulation in five strains of picoeukaryotes (<2{\textendash}3 μm), including three novel isolates from the Baltic Sea, and two marine species (Ostreococcus tauri and Micromonas commoda), in cultures grown with added dSi (100 μM). Average bSi accumulation in these novel biosilicifiers was between 30 and 92 amol Si cell-1. Growth rate and cell size of the picoeukaryotes were not affected by dSi addition. Still, the purpose of bSi accumulation in these smaller eukaryotic organisms lacking silicon dependent structures remains unclear. In line with the increasing recognition of picoeukaryotes in biogeochemical cycling, our findings suggest that they can also play a significant role in silica cycling.}, keywords = {RCC4221, RCC827}, issn = {1758-2229}, doi = {10.1111/1758-2229.13144}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/1758-2229.13144}, author = {Churakova, Yelena and Aguilera, Anabella and Charalampous, Evangelia and Conley, Daniel J. and Lundin, Daniel and Pinhassi, Jarone and Farnelid, Hanna} } @booklet {dennu_biological_2023, title = {Biological and genomic resources for the cosmopolitan phytoplankton Bathycoccus: Insights into genetic diversity and major structural variations}, year = {2023}, note = {Pages: 2023.10.16.562038 Section: New Results}, month = {oct}, publisher = {bioRxiv}, abstract = {Population-scale sequencing has become a standard practice to explore the natural genetic diversity underlying adaptation, notably in land plants. However, current sequencing initiatives for eukaryotic phytoplankton primarily concentrate on creating reference genomes for model organisms and characterizing natural communities through metagenomics approaches. Consequently, few species have been thoroughly sequenced and intraspecific genetic diversity remains virtually undescribed, limiting our understanding of diversity and adaptation mechanisms. Here we report a biological and genomic resource to explore the genetic diversity of the cosmopolitan and ecologically important Bathycoccus genus. To span broad geographical and temporal scales, we selected available strains but also isolated and genotyped strains from both the Banyuls bay (Mediterranean sea) and the Baffin bay (Arctic ocean). By combining ONT long reads and Illumina short reads technologies, we produced and annotated 28 Bathycoccus sp. de novo assembled genomes of high quality, including 24 genomes of Bathycoccus prasinos strains along a latitudinal gradient between 40{\textdegree} and 78{\textdegree} North, one reference genome of the Bathycoccus calidus species and 3 genomes of a yet undescribed Bathycoccus species named Bathycoccus catiminus. We assessed the genetic diversity of this genus through phylogenomic analyses and highlighted the central role of this genomic resource in providing new insights into the diversity of outlier chromosomal structures. The Bathycoccus biological and genomic resources offer a robust framework for investigating the diversity and adaptation mechanisms of eukaryotic phytoplankton in the Ocean. Significance statement Comparative and functional approaches for the study of eukaryotic phytoplankton and their adaptation to latitudes and seasons that rely on extensive biological and genomic resources are currently lacking. Here we report such resources and describe the natural diversity of the cosmopolitan phytoplankton Bathycoccus, providing insights into its species and intraspecific diversity and establishing it as a robust model for functional and ecological studies.}, keywords = {RCC1615, RCC1868, RCC4222, RCC4752, RCC5417, RCC685, RCC716}, doi = {10.1101/2023.10.16.562038}, url = {https://www.biorxiv.org/content/10.1101/2023.10.16.562038v1}, author = {Dennu, Louis and Devic, Martine and Rigonato, Janaina and Falciatore, Angela and Lozano, Jean-Claude and Verg{\'e}, Val{\'e}rie and Mariac, C{\'e}dric and Jaillon, Olivier and Team, The Dark Edge genomics sampling and Sabot, Fran{\c c}ois and Bouget, Fran{\c c}ois-Yves} } @article {cruz_bioprospecting_2023, title = {Bioprospecting for industrially relevant exopolysaccharide-producing cyanobacteria under Portuguese simulated climate}, journal = {Scientific Reports}, volume = {13}, number = {1}, year = {2023}, note = {Number: 1 Publisher: Nature Publishing Group}, pages = {13561}, abstract = {Cyanobacterial exopolysaccharides (EPS) are potential candidates for the production of sustainable biopolymers. Although the bioactive and physicochemical properties of cyanobacterial-based EPS are attractive, their commercial exploitation is limited by the high production costs. Bioprospecting and characterizing novel EPS-producing strains for industrially relevant conditions is key to facilitate their implementation in various biotechnological applications and fields. In the present work, we selected twenty-five Portuguese cyanobacterial strains from a diverse taxonomic range (including some genera studied for the first time) to be grown in diel light and temperature, simulating the Portuguese climate conditions, and evaluated their growth performance and proximal composition of macronutrients. Synechocystis and Cyanobium genera, from marine and freshwater origin, were highlighted as fast-growing (0.1{\textendash}0.2~g~L-1~day-1) with distinct biomass composition. Synechocystis sp. LEGE 07367 and Chroococcales cyanobacterium LEGE 19970, showed a production of 0.3 and 0.4~g~L-1 of released polysaccharides (RPS). These were found to be glucan-based polymers with high molecular weight and a low number of monosaccharides than usually reported for cyanobacterial EPS. In addition, the absence of known cyanotoxins in these two RPS producers was also confirmed. This work provides the initial steps for the development of cyanobacterial EPS bioprocesses under the Portuguese climate.}, keywords = {Biochemistry, Biotechnology, Microbiology, rcc2380}, issn = {2045-2322}, doi = {10.1038/s41598-023-40542-6}, url = {https://www.nature.com/articles/s41598-023-40542-6}, author = {Cruz, Jos{\'e} Diogo and Delattre, C{\'e}dric and Felpeto, Aldo Barreiro and Pereira, Hugo and Pierre, Guillaume and Morais, Jo{\~a}o and Petit, Emmanuel and Silva, Joana and Azevedo, Joana and Elboutachfaiti, Redouan and Maia, In{\^e}s B. and Dubessay, Pascal and Michaud, Philippe and Vasconcelos, Vitor} } @article {florenza_choice_2023, title = {Choice of methodology and surrogate prey are decisive for the quality of protistan bacterivory rate estimates}, journal = {Aquatic Microbial Ecology}, volume = {89}, year = {2023}, month = {mar}, pages = {43{\textendash}53}, abstract = {Microeukaryote predation on bacteria is a fundamental phenomenon to understand energy and nutrient dynamics at the base of the aquatic food web. To date, the most prevalent way to estimate grazing rates is by using epifluorescence microscopy to enumerate ingestion events of fluorescently labelled tracers (FLTs) after short-term incubation experiments. However, this approach can be sensitive to the type of FLT, requires skillful preparation of the samples and is limited to small sample sizes. We tested the susceptibility of rate estimates to the choice of prey and made a side-by-side comparison between microscopy and flow cytometry when recording ingestion by a bacterivorous flagellate. Short-term uptake experiments were established using 5 types of FLTs differing in quality (living, dead or inert) and size (large or small), with Ochromonas triangulata as a model flagellate. The experiments showed that (1) each of the different prey types yielded different clearing rates, ranging from 0.5 to 3.6 nl cell-1 h-1, with the largest differences (3fold or higher) between small prey (lower rates) and large prey (higher rates); (2) the cytometry estimate differed significantly from the microscopy estimate in 3 out of 4 experimental configurations; and (3) the precision of the cytometric analysis was greater, with > 3-fold higher uncertainty associated with microscopy counting. Our results validate that flow cytometry provides a more precise bacterivory estimate, and that the choice of FLT influences the grazing rate estimate to a high extent regardless of the analytical method used.}, keywords = {RCC21}, issn = {0948-3055, 1616-1564}, doi = {10.3354/ame01996}, url = {https://www.int-res.com/abstracts/ame/v89/p43-53/}, author = {Florenza, J and Bertilsson, S} } @booklet {clark_coccolithophorids_2023, title = {Coccolithophorids precipitate carbonate in clumped isotope equilibrium with seawater}, year = {2023}, month = {nov}, publisher = {EGUsphere}, type = {preprint}, abstract = {Numerous recent studies have tested the clumped isotope (Δ47) thermometer on a variety of biogenic carbonates such as foraminifera and bivalves and showed that all follow a common calibration. While the sample size requirements for a reliable Δ47 measurement have decreased over the years, the availability and preservation of many biogenic carbonates is still 10 limited and/or require substantial time to be extracted from sediments in sufficient amounts. We thus determined the Δ47temperature relationship for coccolith carbonate, which is abundant and often well-preserved in sediments. The carbon and oxygen isotopic compositions of coccolith calcite have limited use in palaeoenvironmental reconstructions due to physiological effects that cause variability in the carbon and oxygen isotopic values. However, the relatively limited data available suggest that clumped isotopes may not be influenced by these effects. We cultured three species of coccolithophores in well15 constrained carbonate system conditions with a CO2(aq) between 5 and 45 μM and temperatures between 6{\textdegree}C and 27{\textdegree}C.}, keywords = {RCC1130, RCC1303, RCC3370}, doi = {10.5194/egusphere-2023-2581}, url = {https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2581/}, author = {Clark, Alexander J. and Torres-Romero, Ismael and Jaggi, Madalina and Bernasconi, Stefano M. and Stoll, Heather M.} } @article {arnaldo_comparison_2023, title = {Comparison of different small-scale cultivation methods towards the valorization of a marine benthic diatom strain for lipid production}, journal = {Algal Research}, year = {2023}, pages = {103327}, keywords = {RCC5813}, issn = {22119264}, doi = {10.1016/j.algal.2023.103327}, url = {https://linkinghub.elsevier.com/retrieve/pii/S2211926423003600}, author = {Arnaldo, Mary Dianne Grace and Gamage, Nadeeshani Dehel and Jaffrenou, Agathe and Rabesaotra, Vony and Mossion, Aur{\'e}lie and Wielgosz-Collin, Ga{\"e}tane and M{\'e}l{\'e}der, Vona} } @article {edullantes_comparison_2023, title = {Comparison of thermal traits between non-toxic and potentially toxic marine phytoplankton: Implications to their responses to ocean warming}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {562}, year = {2023}, pages = {151883}, abstract = {Understanding the effect of temperature on growth in marine phytoplankton is crucial in predicting the biogeography and phenology of algal blooms in the warming ocean. Here, we investigated the temperature dependence of the growth of non-toxic and potentially toxic marine phytoplankton. Using non-toxic strains (Prorocentrum sp. NRR 188, Prorocentrum micans CCAP 1136/15, and Alexandrium tamutum PARALEX 242) and potentially toxic strains (Prorocentrum minimum Poulet, Prorocentrum lima CCAP 1136/11, and Alexandrium minutum PARALEX 246) of dinoflagellates as test organisms, we measured their growth rates along a wide temperature gradient and estimated their maximum growth rates, thermal traits (e.g. thermal optima (Topt), critical thermal minima (CTmin), critical thermal maximum (CTmax), fundamental thermal niche (FTN), and skewness), thermal sensitivity, and warming vulnerability. To allow a comparison of these traits with an adequate number of observations, we independently analyzed datasets compiled from published laboratory experiments. Our experiments revealed that the temperature traits were independent of the toxicity of phytoplankton, except for Topt and CTmax. Also, the results of the analysis of the published datasets showed that maximum growth rates and thermal traits were comparable between non-toxic and potentially toxic phytoplankton. Our findings suggest that non-toxic and potentially toxic phytoplankton have generally comparable temperature traits that they can use to respond to climate change. However, depending on the climate scenario, non-toxic phytoplankton may be more vulnerable to warming than potentially toxic phytoplankton. Further studies are needed to improve our understanding of the response of marine phytoplankton to temperature, which can advance our ability to predict algal blooms in response to ongoing climate change.}, keywords = {Growth experiment, Growth models, Microalgal ecophysiology, RCC2649, RCC291, RCC3034, Thermal performance, Thermal physiology, Toxic microalgae}, issn = {0022-0981}, doi = {10.1016/j.jembe.2023.151883}, url = {https://www.sciencedirect.com/science/article/pii/S0022098123000151}, author = {Edullantes, Brisneve and Low-Decarie, Etienne and Steinke, Michael and Cameron, Tom} } @article {graeff_composition_2023, title = {Composition of galactolipids, betaine lipids and triglyceride-associated fatty acids of the symbiotic dinoflagellate Zooxanthella (Brandtodinium) nutricula: A glimpse into polyunsaturated fatty acids available to its polycystine radiolarian host}, journal = {Phycological Research}, volume = {n/a}, number = {n/a}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/pre.12530}, abstract = {

Zooxanthella nutricula is a photosynthetic dinoflagellate symbiont of polycystine radiolarians. As such, it is hypothesized to provide fixed organic carbon, including in the form of acylglycerolipids and sterols, to its non-photosynthetic host. We have previously characterized the sterols of Z. nutricula that may be transferred to its host and, in the present study, have turned our attention to three classes of fatty acid-containing lipids, chloroplast-associated galactolipids, betaine lipids, which are non-phosphorylated phospholipid analogs present in many eukaryotes, and triglycerides. Zooxanthella nutricula was observed using positive-ion electrospray/mass spectrometry (ESI/MS) and ESI/MS/MS to produce the galactolipids mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively) enriched in octadecapentaenoic (18:5(n-3)) and octadecatetraenoic (18:4(n-3)) acid to place it within a group of peridinin-containing dinoflagellates in a C18/C18 (sn-1/sn-2 fatty acid regiochemistry) cluster, as opposed to another cluster with C20/C18 MGDG and DGDG, where the C20 fatty acid is eicosapentaenoic acid (20:5(n-3)) and the C18 fatty acid is either 18:5(n-3) or 18:4(n-3). Zooxanthella nutricula was also observed to produce 38:10 (total number of fatty acid carbons:total number of double bonds), 38:6, and 44:7 diacylglycerylcarboxyhydroxymethylcholine (DGCC) as the sole type of betaine lipid. Although it is more difficult to determine which fatty acids are present in the sn-1 and sn-2 positions on the glycerol backbone of DGCC using ESI/MS/MS, gas chromatography/mass spectrometry (GC/MS)-based examination indicated the putatively DGCC-associated polyunsaturated fatty acid (PUFA) docosahexaenoic acid (22:6(n-3)). Coupled with the C18 PUFAs of MGDG and DGDG, and fatty acids associated with triglycerides (also examined via GC/MS), Z. nutricula could serve as a rich source of PUFAs for its radiolarian host. These data demonstrate that Z. nutricula produces a similar set of PUFA-containing lipids as Symbiodinium microadriaticum, a photosynthetic dinoflagellate symbiont of cnidarians, indicating a metabolic commonality in these phylogenetically discrete dinoflagellate symbionts with unrelated host organisms.

}, keywords = {Brandtodinium, chloroplast, Dinoflagellate, Dinophyceae, lipid, RCC3387, Zooxanthella}, issn = {1440-1835}, doi = {10.1111/pre.12530}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/pre.12530}, author = {Graeff, Jori E. and Leblond, Jeffrey D.} } @booklet {de_vries_critical_2023, title = {A critical trade-off between nitrogen quota and growth allows Coccolithus braarudii life cycle phases{\textquoteright} to exploit varying environment}, year = {2023}, publisher = {Biodiversity and Ecosystem Function: Marine}, type = {preprint}, abstract = {Coccolithophores have a distinct haplo-diplontic life cycle, which allows them to grow and divide in two different life cycle phases (haploid and diploid). These life cycle phases vary significantly in inorganic carbon content and morphology, and inhabit distinct niches, with haploids generally preferring low-nutrient and high-temperature and -light environments. This niche contrast indicates different physiology of the life cycle phases, which is considered here in the context of a trait trade-off 5 framework, in which a particular set of traits comes with both costs and benefits. However, coccolithophore{\textquoteright}s phase trade-offs are not fully identified, limiting our understanding of the functionality of the coccolithophore life cycle. Here, we investigate the response of the two life cycle phases of the coccolithophore Coccolithus braarudii to key environmental drivers: light, temperature and nutrients, using laboratory experiments. With this data, we identify the main trade-offs of each life cycle phase and use models to test the role of such trade-offs under different environmental conditions.}, keywords = {RCC1200, RCC1203, RCC3777, RCC3779, RCC6535}, doi = {10.5194/egusphere-2023-880}, url = {https://egusphere.copernicus.org/preprints/2023/egusphere-2023-880/}, author = {De Vries, Joost and Monteiro, Fanny and Langer, Gerald and Brownlee, Colin and Wheeler, Glen} } @article {ben-joseph_crystallization_2023, title = {Crystallization of Coccolith Calcite at Different Life-Cycle Phases Exhibits Distinct Degrees of Cellular Confinement}, journal = {Small Structures}, volume = {n/a}, number = {n/a}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/sstr.202200353}, pages = {2200353}, abstract = {Coccolithophores are a group of unicellular marine algae that shape global geochemical cycles via the production of calcium carbonate crystals. Interestingly, different life-cycle phases of the same coccolithophore species produce very different calcitic scales, called coccoliths. In the widely studied diploid phase, the crystals have anisotropic and complex morphologies, while haploid cells produce coccoliths consisting solely of calcite crystals with simple rhombohedral morphology. Understanding how these two life-cycle phases control crystallization is a highly sought-after goal, yet, haploid phase crystallization has rarely been studied, and the process by which they form is unknown. Herein, advanced electron microscopy is employed to elucidate the cellular architecture of the calcification process in haploid cells. The results show that in contrast to diploid-phase calcification, the coccolith-forming vesicle of haploid-phase cells is voluminous. In this solution-like environment, the crystals nucleate and grow asynchronously in a process that resembles calcite growth in bulk solution, leading to the simple morphologies of the crystals. The two distinct mineralization regimes of coccolithophore life-cycle phases suggest that cellular architecture, and specifically confinement of the crystallization process, is a pivotal determinant of biomineral morphology and assembly.}, keywords = {biomineralization, calcites, Coccoliths, crystal growths, haploid{\textendash}diploid life cycles, RCC1181, RCC3777}, issn = {2688-4062}, doi = {10.1002/sstr.202200353}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sstr.202200353}, author = {Ben-Joseph, Oz and de Haan, Diede and Rechav, Katya and Shimoni, Eyal and Levin-Zaidman, Smadar and Langer, Gerald and Probert, Ian and Wheeler, Glen L. and Gal, Assaf} } @article {coello-camba_design_2023, title = {Design and use of a new primer pair for the characterization of the cyanobacteria Synechococcus and Prochlorococcus communities targeting petB gene through metabarcoding approaches.}, journal = {MethodsX}, year = {2023}, month = {oct}, pages = {102444}, abstract = {During the last years, the application of next-generation sequencing (NGS) technologies to search for specific genetic markers has become a crucial method for the characterization of microbial communities. Illumina MiSeq, likely the most widespread NGS platform for metabarcoding experiments and taxonomic classification, allows processing shorter reads than the classical SANGER sequencing method and therefore requires specific primer pairs that produce shorter amplicons. Specifically, for the analysis of the commonly studied Prochlorococcus and Synechococcus communities, the petB marker gene has recently stood out as able to provide deep coverage to determine the microdiversity of the community.. However, current petB primer set produce a 597 bp amplicon that is not suitable for MiSeq chemistry. Here, we designed and tested a petB primer pair that targets both Prochlorococcus and Synechococcus communities producing an appropriate amplicon to be used with state-of-the-art Illumina MiSeq. This new primer set allows the classification of both groups to a low taxonomic level and is therefore suitable for high throughput experiments using MiSeq technologies, therefore constituting a useful, novel tool to facilitate further studies on Prochlorococcus and Synechococcus communities. {\textbullet} This work describes the de novo design of a Prochlorococcus and Synechococcus-specific petB primer pair, allowing the characterization of both populations to a low taxonomic level. {\textbullet} This primer pair is suitable for widespread Illumina MiSeq sequencing technologies. {\textbullet} petB was confirmed as an adequate target for the characterization of both picocyanobacteria.}, keywords = {cyanobacteria, Illumina MiSeq, RCC156, rcc162, RCC2319, RCC2372, RCC2378, RCC2383, RCC2384, RCC2455, RCC2529, RCC2531, RCC2554, RCC3377, RCC407, RCC408, sequencing}, issn = {2215-0161}, doi = {10.1016/j.mex.2023.102444}, url = {https://www.sciencedirect.com/science/article/pii/S2215016123004405}, author = {Coello-Camba, Alexandra and D{\'\i}az-R{\'u}a, Rub{\'e}n and Agusti, Susana} } @article {saide_diatom_2023, title = {The Diatom Cylindrotheca closterium and the Chlorophyll Breakdown Product Pheophorbide a for Photodynamic Therapy Applications}, journal = {Applied Sciences}, volume = {13}, number = {4}, year = {2023}, note = {Number: 4 Publisher: Multidisciplinary Digital Publishing Institute}, pages = {2590}, abstract = {Microalgae, eukaryotic unicellular plants that are distributed worldwide, have been shown to exert anti-proliferative and anticancer activities on various human cancer cell lines. An example of a microalgal bioactive compound is a chlorophyll breakdown product named Pheophorbide a (Ppa), which has been reported to have anti-proliferative properties against various cell lines. This compound has also been tested with light exposure in photodynamic therapy for cancer treatment. In this paper, we screened eleven marine microalgae against a panel of cancer cells, and evaluated the synergistic anti-proliferative effect with Pheophorbide a, with and without photo-activation. The results showed significant anti-proliferative activity against melanoma cells when Ppa was combined with fraction E of the diatom Cylindrotheca closterium plus 1 h photo-activation. Its activity was also analyzed using gene expression and Western blot experiments. Altogether, these data give new insights into the possible application of microalgae for photodynamic therapy.}, keywords = {biotechnological applications, cancer, Microalgae, Pheophorbide \textita, photodynamic therapy, RCC1712, \textitCylindrotheca closterium}, issn = {2076-3417}, doi = {10.3390/app13042590}, url = {https://www.mdpi.com/2076-3417/13/4/2590}, author = {Saide, Assunta and Riccio, Gennaro and Ianora, Adrianna and Lauritano, Chiara} } @article {ruan_different_2023, title = {Different photosynthetic responses of haploid and diploid Emiliania huxleyi (Prymnesiophyceae) to high light and ultraviolet radiation}, journal = {Bioresources and Bioprocessing}, volume = {10}, number = {1}, year = {2023}, month = {jul}, pages = {40}, abstract = {Solar radiation varies quantitatively and qualitatively while penetrating through the seawater column and thus is one of the most important environmental factors shaping the vertical distribution pattern of phytoplankton. The haploid and diploid life-cycle phases of coccolithophores might have different vertical distribution preferences. Therefore, the two phases respond differently to high solar photosynthetically active radiation (PAR, 400{\textendash}700~nm) and ultraviolet radiation (UVR, 280{\textendash}400~nm). To test this, the haploid and diploid Emiliania huxleyi were exposed to oversaturating irradiance. In the presence of PAR alone, the effective quantum yield was reduced by 10\% more due to the higher damage rate of photosystem II in haploid cells than in diploid cells. The addition of UVR resulted in further inhibition of the quantum yield for both haploid and diploid cells in the first 25~min, partly because of the increased damage of photosystem II. Intriguingly, this UVR-induced inhibition of the haploid cells completely recovered half an hour later. This recovery was confirmed by the comparable maximum quantum yields, maximum relative electron transport rates and yields of the haploid cells treated with PAR and PAR + UVR. Our data indicated that photosynthesis of the haploid phase was more sensitive to high visible light than the diploid phase but resistant to UVR-induced inhibition, reflecting the ecological niches to which this species adapts.}, keywords = {Diploid phase, Effective quantum yield, Emiliania huxleyi, Haploid phase, rcc1217, Ultraviolet radiation (UVR)}, issn = {2197-4365}, doi = {10.1186/s40643-023-00660-5}, url = {https://doi.org/10.1186/s40643-023-00660-5}, author = {Ruan, Zuoxi and Lu, Meifang and Lin, Hongmin and Chen, Shanwen and Li, Ping and Chen, Weizhou and Xu, Huijuan and Qiu, Dajun} } @article {yu_does_2023, title = {Does the life cycle stage matter for distinguishing phytoplankton via fluoro-electrochemical microscopy?}, journal = {Cell Reports Physical Science}, year = {2023}, pages = {101223}, abstract = {Phytoplankton have species-specific responses toward electrogenerated oxidants, allowing high-throughput species analysis. Herein, a fluoro-electrochemical method is used to expose single Chlamydomonas concordia vegetative cells at different points within their life cycle to electro-generated oxidants from seawater. The resulting decay in fluorescence from chlorophyll-a is measured as a function of time and drops to zero for phytoplankton adjacent to the electrode over a period of a few seconds. The chlorophyll-a transient timescale allows mother cells, which are distinctively larger and require a larger quantity of oxidants, to be distinguished from either zoospores or {\textquotedblleft}growing{\textquotedblright} cells, while all the cells show the same intrinsic susceptibility modulated only by the size of the phytoplankton. These observations are essential for the future automated characterization of the speciation of phytoplankton populations as they show that there is no need to manually identify the life cycle stage.}, keywords = {electrogenerated radicals, fluoro-electrochemistry, Green algae, life cycle, marine phytoplankton, oxidative damage, RCC1, remote sensing, susceptibility library}, issn = {2666-3864}, doi = {10.1016/j.xcrp.2022.101223}, url = {https://www.sciencedirect.com/science/article/pii/S2666386422005410}, author = {Yu, Jiahao and Yang, Minjun and Batchelor-McAuley, Christopher and Barton, Samuel and Rickaby, Rosalind E. M. and Bouman, Heather A. and Compton, Richard G.} } @booklet {sirin_effects_2023, title = {Effects of Nitrogen Starvation on Growth and Biochemical Composition of Some Microalgae Species}, year = {2023}, month = {apr}, publisher = {In Review}, type = {preprint}, abstract = {Abstract Nitrogen is one of the most important nutrient sources for the growth of microalgae. We studied the effects of nitrogen starvation on the growth responses, biochemical composition and fatty acid profile of Dunaliella tertiolecta, Phaeodactylum tricornutum and Nannochloropsis oculata . The lack of nitrogen caused changes in carbohydrate, protein, lipid and fatty acid composition in all examined microalgae. The carbohydrate content increased 59\% in D. tertiolecta , while the lipid level increased 139\% in P. tricornutum under nitrogen stress conditions. Nitrogen starvation increased the oligosaccharide and polysaccharide contents of D. tertiolecta 4.18-fold and 3.77-fold, respectively. Furthermore, triacylglycerol (TAG) levels in N. oculata and P. tricornutum increased 2.3-fold and 7.4-fold, respectively. The dramatic increase in the amount of TAG is important for the use of these microalgae as raw materials in biodiesel. Nitrogen starvation increased the amounts of oligosaccharides and polysaccharides of D. tertiolecta , while increased eicosapentaenoic acid (EPA) in N. oculata and docosahexaenoic acid (DHA) content in P. tricornutum . The amount of polyunsaturated fatty acids (PUFAs), EPA, DHA, oligosaccharides and polysaccharides in microalgal species can be increased without using the too costly nitrogen source in the culture conditions, which can reduce the most costly of living feeding.}, keywords = {RCC2967}, doi = {10.21203/rs.3.rs-2787376/v1}, url = {https://www.researchsquare.com/article/rs-2787376/v1}, author = {{\c S}i̇Ri̇N, P{\i}nar AKDO{\u G}AN and Serdar, Serpil} } @article {liao_exploring_2023, title = {Exploring the theoretical upper temperature limit of alkenone unsaturation indices: Implications for paleotemperature reconstructions}, journal = {Organic Geochemistry}, volume = {180}, year = {2023}, pages = {104606}, abstract = {The structural specificity, exceptional diagenetic stability, and linear response of unsaturation to temperature have made alkenones an indispensable tool for reconstructing past sea surface temperatures, with the well known U37K' proxy widely applied in the past 40~years. However, U37K' approaches unity at around 28~{\textdegree}C in cultures of Emiliania huxleyi (E. huxleyi), the most widely distributed alkenone producer in global oceans. Recent studies using surface sediments suggest U38MeK' has \~{}1.5~{\textdegree}C higher upper temperature limits than U37K'. However, E. huxleyi generally does not grow above 28~{\textdegree}C. Gephyrocapsa oceanica (G. oceanica), on the other hand, is the dominant alkenone producer when sea surface temperature is above 22~{\textdegree}C and thrives in ocean regions such as the Pacific Warm Pool. So far there have been no culture data for G. oceanica above 29~{\textdegree}C to evaluate the temperature response of alkenone distributions and the (theoretical) upper temperature limit of alkenone unsaturation indices. Here we performed the first culture experiments on two strains of G. oceanica isolated from warm ocean sites at up to 32~{\textdegree}C: RCC6484 from the Pacific Warm Pool and RCC3483 from the South China Sea. We show both strains display higher growth rates at higher temperature, with the highest growth rates at 32~{\textdegree}C (the highest temperature we tested), although alkenone production per cell decreases as temperature increases. Importantly, U37K' and U38MeK' values of RCC6484 and RCC3483 continue to respond to temperature changes beyond 28~{\textdegree}C, although temperature sensitivity decreases significantly above 28~{\textdegree}C. Above 30~{\textdegree}C, U37K' and U38MeK' responses to temperature further diminish, limiting their potential for paleo-SST applications using the currently available analytical technology. The ratio of C38:3 over C38:2 methyl ketone is on average 11 times higher than the ratio of C37:3 over C37:2 from 24 to 32~{\textdegree}C, suggesting a greater potential of using U38MeK' for paleotemperature reconstruction in high temperature settings.}, keywords = {Culture experiments, RCC3483, RCC6484, Temperature calibrations}, issn = {0146-6380}, doi = {10.1016/j.orggeochem.2023.104606}, url = {https://www.sciencedirect.com/science/article/pii/S0146638023000529}, author = {Liao, Sian and Novak, Joseph and Huang, Yongsong} } @article {coleman_fine-tuning_2023, title = {Fine-tuning the flavor of Tetraselmis chuii by modifying nitrogen supply}, journal = {Algal Research}, year = {2023}, pages = {103208}, abstract = {Dried Tetraselmis chuii biomass has potential as flavoring agent for the development of plant-based seafood alternatives because of its seafood-like aroma and strong umami taste. Depending on the cultivation conditions, microalgae can adapt their metabolism, resulting in a change in biochemical composition. The aim of this study was to assess if the flavor of T. chuii could be modified by changing the nitrogen (N) supply in the cultivation medium in order to maximize the potential of T. chuii as flavoring agent. The sensory evaluation by a trained panel showed that the T. chuii biomass obtained from N starved cultivation conditions (N-deplete) is characterized by a significantly stronger odor intensity and earthy-like off-odor compared to T. chuii biomass obtained from N sufficient cultivation conditions (N-replete). The analysis of volatile organic compounds (VOCs) using SPME-GC{\textendash}MS showed that these odor features of N-deplete biomass are attributed to an increased formation of odor-active VOCs including 2,3-butanedione, 3-methylbutanal, 3-methylbutanol and sulfur-containing dimethyl sulfide and dimethyl disulfide. In contrast, the T. chuii N-replete biomass possessed a significantly stronger taste intensity, umami and salty taste compared to the T. chuii N-deplete biomass. The higher umami is attributed to the significantly higher free glutamic acid (Glu) and adenosine monophosphate (AMP) concentrations in N-replete biomass compared to N-deplete biomass. This study illustrates that flavor and palatability of microalgae biomass is strongly affected by cultivating conditions and modifying these conditions can be an important tool in the development of plant-based seafood alternatives.}, keywords = {Microalgae, Nitrogen starvation, RCC128, Sensory evaluation, Umami, Volatile organic compounds}, issn = {2211-9264}, doi = {10.1016/j.algal.2023.103208}, url = {https://www.sciencedirect.com/science/article/pii/S2211926423002412}, author = {Coleman, Bert and Van Poucke, Christof and Dewitte, Bavo and Casciaro, Valentina and Moerdijk-Poortvliet, Tanja and Muylaert, Koenraad and Robbens, Johan} } @article {sands_genetic_2023, title = {Genetic and physiological responses to light quality in a deep ocean ecotype of Ostreococcus, an ecologically important photosynthetic picoeukaryote}, journal = {Journal of Experimental Botany}, year = {2023}, pages = {erad347}, abstract = {Abstract Phytoplankton are exposed to dramatic variations in light quality when cells are carried by upwelling or downwelling currents or encounter sediment. We investigated the potential impact of light quality changes in Ostreococcus, a key marine photosynthetic picoeukaryote, by analysing changes in its transcriptome, pigment content and photophysiology after acclimation to monochromatic red, green or blue light. The clade B species RCC809, isolated from the deep euphotic zone of the tropical Atlantic Ocean, responded to blue light by accelerating cell division at the expense of storage reserves and by increasing the relative level of blue-light absorbing pigments. RCC809 responded to red and green light by increasing its potential for photoprotection. In contrast, the clade A species OTTH0595, which originates from a shallow water environment, showed no difference in photosynthetic properties and minor differences in carotenoid contents between light qualities. This was associated with the loss of candidate lightquality responsive promoter motifs identified in RCC809 genes. These results demonstrate that light quality can have a major influence on the physiology of eukaryotic phytoplankton and suggest that different light quality environments can drive selection for diverse patterns of responsiveness and environmental niche partitioning.}, keywords = {Rcc141, RCC4221, RCC745, RCC809}, issn = {0022-0957, 1460-2431}, doi = {10.1093/jxb/erad347}, url = {https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erad347/7258950}, author = {Sands, Elizabeth and Davies, Sian and Puxty, Richard John and Verg{\'e}, Val{\'e}rie and Bouget, Fran{\c c}ois-Yves and Scanlan, David John and Carr{\'e}, Isabelle Alice} } @article {ruvindy_genomic_2023, title = {Genomic copy number variability at the genus, species and population levels impacts in situ ecological analyses of dinoflagellates and harmful algal blooms}, journal = {ISME Communications}, volume = {3}, number = {1}, year = {2023}, note = {Number: 1 Publisher: Nature Publishing Group}, month = {jul}, pages = {1{\textendash}11}, abstract = {The application of meta-barcoding, qPCR, and metagenomics to aquatic eukaryotic microbial communities requires knowledge of genomic copy number variability (CNV). CNV may be particularly relevant to functional genes, impacting dosage and expression, yet little is known of the scale and role of CNV in microbial eukaryotes. Here, we quantify CNV of rRNA and a gene involved in Paralytic Shellfish Toxin (PST) synthesis (sxtA4), in 51 strains of 4 Alexandrium (Dinophyceae) species. Genomes varied up to threefold within species and \textasciitilde7-fold amongst species, with the largest (A. pacificum, 130 {\textpm} 1.3 pg cell-1 /\textasciitilde127 Gbp) in the largest size category of any eukaryote. Genomic copy numbers (GCN) of rRNA varied by 6 orders of magnitude amongst Alexandrium (102{\textendash} 108 copies cell-1) and were significantly related to genome size. Within the population CNV of rRNA was 2 orders of magnitude (105 {\textendash} 107 cell-1) in 15 isolates from one population, demonstrating that quantitative data based on rRNA genes needs considerable caution in interpretation, even if validated against locally isolated strains. Despite up to 30 years in laboratory culture, rRNA CNV and genome size variability were not correlated with time in culture. Cell volume was only weakly associated with rRNA GCN (20{\textendash}22\% variance explained across dinoflagellates, 4\% in Gonyaulacales). GCN of sxtA4 varied from 0{\textendash}102 copies cell-1, was significantly related to PSTs (ng cell-1), displaying a gene dosage effect modulating PST production. Our data indicate that in dinoflagellates, a major marine eukaryotic group, low-copy functional genes are more reliable and informative targets for quantification of ecological processes than unstable rRNA genes.}, keywords = {Molecular ecology, Molecular Evolution, RCC3145, RCC4874, RCC4876, RCC4877, RCC4879}, issn = {2730-6151}, doi = {10.1038/s43705-023-00274-0}, url = {https://www.nature.com/articles/s43705-023-00274-0}, author = {Ruvindy, Rendy and Barua, Abanti and Bolch, Christopher J. S. and Sarowar, Chowdhury and Savela, Henna and Murray, Shauna A.} } @article {lopez-pacheco_growth_2023, title = {Growth Behavior, Biomass Composition and Fatty Acid Methyl Esters (FAMEs) Production Potential of Chlamydomonas reinhardtii, and Chlorella vulgaris Cultures}, journal = {Marine Drugs}, volume = {21}, number = {8}, year = {2023}, month = {aug}, pages = {450}, abstract = {The production of biomolecules by microalgae has a wide range of applications in the development of various materials and products, such as biodiesel, food supplements, and cosmetics. Microalgae biomass can be produced using waste and in a smaller space than other types of crops (e.g., soja, corn), which shows microalgae{\textquoteright}s great potential as a source of biomass. Among the produced biomolecules of greatest interest are carbohydrates, proteins, lipids, and fatty acids. In this study, the production of these biomolecules was determined in two strains of microalgae (Chlamydomonas reinhardtii and Chlorella vulgaris) when exposed to different concentrations of nitrogen, phosphorus, and sulfur. Results show a significant microalgal growth (3.69 g L-1) and carbohydrates (163 mg g-1) increase in C. reinhardtii under low nitrogen concentration. Also, higher lipids content was produced under low sulfur concentration (246 mg g-1). It was observed that sulfur variation could affect in a negative way proteins production in C. reinhardtii culture. In the case of C. vulgaris, a higher biomass production was obtained in the standard culture medium (1.37 g L-1), and under a low-phosphorus condition, C. vulgaris produced a higher lipids concentration (248 mg g-1). It was observed that a low concentration of nitrogen had a better effect on the accumulation of fatty acid methyl esters (FAMEs) (C16-C18) in both microalgae. These results lead us to visualize the effects that the variation in macronutrients can have on the growth of microalgae and their possible utility for the production of microalgae-based subproducts.}, keywords = {RCC2488}, issn = {1660-3397}, doi = {10.3390/md21080450}, url = {https://www.mdpi.com/1660-3397/21/8/450}, author = {L{\'o}pez-Pacheco, Itzel Y. and Ayala-Moreno, Victoria Guadalupe and Mejia-Melara, Catherinne Arlette and Rodr{\'\i}guez-Rodr{\'\i}guez, Jos{\'e} and Cuellar-Bermudez, Sara P. and Gonz{\'a}lez-Gonz{\'a}lez, Reyna Berenice and Coronado-Apodaca, Karina G. and Farfan-Cabrera, Leonardo I. and Gonz{\'a}lez-Meza, Georgia Mar{\'\i}a and Iqbal, Hafiz M. N. and Parra-Sald{\'\i}var, Roberto} } @booklet {devic_indel_2023, title = {An INDEL genomic approach to explore population diversity of phytoplankton : \textit{Bathycoccus , a case study}, year = {2023}, publisher = {Ecology}, type = {preprint}, abstract = {Abstract Although metabarcoding has generated large dataset on world-wide phytoplankton species diversity, little is known about the intraspecies diversity underlying adaptation to environmental niches. To gain insight into population diversity, a novel INDEL based method was developed on Bathycoccus prasinos . Oxford Nanopore Technology (ONT) sequencing was first used to characterise structural variants (SV) among the genomes of Bathycoccus sampled from geographically distinct regions in the world ocean. Markers derived from INDEL were validated by PCR and sequencing in the world-wide strains. These markers were then used to genotype 55 Bathycoccus strains isolated during the winter bloom 2018-2019 in the bay of Banyuls-sur-Mer. With five markers, eight Multi Loci Genotypes (MLG) were determined, two of which represented 53\% and 29\% of the isolates. Physiological studies confirmed that isolates are phenotypically different, cells isolated in February growing better at low temperature than those isolated in December and January. When tested directly on environmental samples, two diversity markers showed a similar allele frequency in sea water as in individual Bathycoccus strains isolated at the same period. We conclude that these markers constitute a resource to identify the most abundant variant alleles in a given bloom. A follow-up on three consecutive blooms revealed differences in allele abundance during the course of a bloom, particularly at initiation and between years. This INDEL-based genotyping constitutes a new methodological approach that may be used to assess the population structure and diversity of other species.}, keywords = {RCC1613, RCC1615, RCC1868, RCC4222, RCC4752, RCC5417, RCC685}, doi = {10.1101/2023.02.09.527951}, url = {http://biorxiv.org/lookup/doi/10.1101/2023.02.09.527951}, author = {Devic, Martine and Mariac, C{\'e}dric and Verg{\'e}, Val{\'e}rie and Schatt, Philipe and Dennu, Louis and Lozano, Jean-Claude and Bouget, Fran{\c c}ois-Yves and Sabot, Fran{\c c}ois} } @article {moreno-cabezuelo_integrated_2023, title = {Integrated Proteomic and Metabolomic Analyses Show Differential Effects of Glucose Availability in Marine Synechococcus and Prochlorococcus}, journal = {Microbiology Spectrum}, year = {2023}, month = {feb}, pages = {e03275{\textendash}22}, abstract = {

We compared changes induced by the addition of 100 nM and 5 mM glucose on the proteome and metabolome complements in Synechococcus sp. strains WH8102, WH7803, and BL107 and Prochlorococcus sp. strains MED4, SS120, and MIT9313, grown either under standard light conditions or in darkness. Our results suggested that glucose is metabolized by these cyanobacteria, using primarily the oxidative pentoses and Calvin pathways, while no proof was found for the involvement of the EntnerDoudoroff pathway in this process. We observed differences in the effects of glucose availability, both between genera and between Prochlorococcus MED4 and SS120 strains, which might be related to their specific adaptations to the environment. We found evidence for fermentation in Prochlorococcus sp. strain SS120 and Synechococcus sp. strain WH8102 after 5 mM glucose addition. Our results additionally suggested that marine cyanobacteria can detect nanomolar glucose concentrations in the environment and that glucose might be used to sustain metabolism under darkness. Furthermore, the KaiB and KaiC proteins were also affected in Synechococcus sp. WH8102, pointing to a direct link between glucose assimilation and circadian rhythms in marine cyanobacteria. In conclusion, our study provides a wide overview on the metabolic effects induced by glucose availability in representative strains of the diverse marine picocyanobacteria, providing further evidence for the importance of mixotrophy in marine picocyanobacteria.

}, keywords = {RCC156, RCC407, RCC515, rcc539, rcc752}, issn = {2165-0497}, doi = {10.1128/spectrum.03275-22}, url = {https://journals.asm.org/doi/10.1128/spectrum.03275-22}, author = {Moreno-Cabezuelo, Jos{\'e} {\'A}ngel and G{\'o}mez-Baena, Guadalupe and D{\'\i}ez, Jes{\'u}s and Garc{\'\i}a-Fern{\'a}ndez, Jos{\'e} Manuel}, editor = {Hom, Erik F. Y.} } @article {groussman_marferret_2023, title = {MarFERReT, an open-source, version-controlled reference library of marine microbial eukaryote functional genes}, journal = {Scientific Data}, volume = {10}, number = {1}, year = {2023}, note = {Number: 1 Publisher: Nature Publishing Group}, pages = {926}, abstract = {Metatranscriptomics generates large volumes of sequence data about transcribed genes in natural environments. Taxonomic annotation of these datasets depends on availability of curated reference sequences. For marine microbial eukaryotes, current reference libraries are limited by gaps in sequenced organism diversity and barriers to updating libraries with new sequence data, resulting in taxonomic annotation of about half of eukaryotic environmental transcripts. Here, we introduce Marine Functional EukaRyotic Reference Taxa (MarFERReT), a marine microbial eukaryotic sequence library designed for use with taxonomic annotation of eukaryotic metatranscriptomes. We gathered 902 publicly accessible marine eukaryote genomes and transcriptomes and assessed their sequence quality and cross-contamination issues, selecting 800 validated entries for inclusion in MarFERReT. Version 1.1 of MarFERReT contains reference sequences from 800 marine eukaryotic genomes and transcriptomes, covering 453 species- and strain-level taxa, totaling nearly 28 million protein sequences with associated NCBI and PR2 Taxonomy identifiers and Pfam functional annotations. The MarFERReT project repository hosts containerized build scripts, documentation on installation and use case examples, and information on new versions of MarFERReT.}, keywords = {Classification and taxonomy, Microbial genetics, transcriptomics}, issn = {2052-4463}, doi = {10.1038/s41597-023-02842-4}, url = {https://www.nature.com/articles/s41597-023-02842-4}, author = {Groussman, R. D. and Blaskowski, S. and Coesel, S. N. and Armbrust, E. V.} } @article {barbosa_microalga_2023, title = {The microalga \textit{Dunaliella and its applications: a review}, journal = {Applied Phycology}, volume = {4}, number = {1}, year = {2023}, pages = {99{\textendash}120}, keywords = {RCC3579, RCC5}, issn = {2638-8081}, doi = {10.1080/26388081.2023.2222318}, url = {https://www.tandfonline.com/doi/full/10.1080/26388081.2023.2222318}, author = {Barbosa, Miguel and In{\'a}cio, Leonardo Garcia and Afonso, Cl{\'e}lia and Maranh{\~a}o, Paulo} } @article {mertens_morpho-molecular_2023, title = {Morpho-molecular analysis of podolampadacean dinoflagellates (Dinophyceae), with the description of two new genera}, journal = {Phycologia}, year = {2023}, note = {Publisher: Taylor \& Francis _eprint: https://doi.org/10.1080/00318884.2022.2158281}, month = {feb}, pages = {1{\textendash}19}, abstract = {Sequences were obtained for 58 podolampadacean single cells from France, Reunion Island (French territories) and Japan (6 SSU rDNA only, 40 SSU+LSU and 12 LSU only). The sequenced taxa belong to five of the eight described genera: Podolampas, Blepharocysta, Lissodinium, Gaarderiella and Mysticella. Two new genera, Alatosphaera and Pseudalatosphaera, were erected to accommodate {\textquoteleft}Blepharocysta{\textquoteright} hermosillae and {\textquoteleft}Blepharocysta{\textquoteright} denticulata. Most genera are well supported by concatenated LSU{\textendash}SSU rDNA phylogenies, with the least support for Lissodinium. Metabarcoding of podolampadaceans using the V4 region of SSU rDNA showed a resolution too low to discriminate genera or species. Roscoffia and Cabra are here considered podolampadaceans, whilst Lessardia is considered to belong in a separate family. The relationship of Rhinodinium to the Podolampadaceae needs further study. Desmoschisis was recorded for the first time in Alatosphaera and Pseudalatosphaera. Several ribotypes need further study to attribute a species name to them.}, keywords = {Alatosphaera, Blepharocysta, desmoschisis, Gaarderiella, Lissodinium, LSU rDNA, Mysticella, Podolampas, Pseudalatosphaera, SSU rDNA}, issn = {0031-8884}, doi = {10.1080/00318884.2022.2158281}, url = {https://doi.org/10.1080/00318884.2022.2158281}, author = {Mertens, Kenneth Neil and Carbonell-Moore, M. Consuelo and Chom{\'e}rat, Nicolas and Bilien, Gwenael and Boulben, Sylviane and Guillou, Laure and Romac, Sarah and Probert, Ian and Ishikawa, Akira and N{\'e}zan, Elisabeth} } @article {veron_new_2023, title = {New species of Pavlovophyceae (Haptophyta) and revision of the genera Exanthemachrysis, Rebecca and Pavlova}, journal = {European Journal of Taxonomy}, volume = {861}, year = {2023}, month = {mar}, pages = {21{\textendash}47}, abstract = {The justification of the 4 genera that currently compose the class Pavlovophyceae is based on a low number of species and a relative paucity of available, traceable and referenced cultures. Previous integrative phylogeny work revealed strains that can refine and strengthen our knowledge of the genera in the class. The application of multiple light and electron microscopy techniques allowed us to prioritize the cytomorphological characters (pyrenoid, thylakoid, stigma, knob-scales, life stage / life cycle) used for the taxonomy of these algae and to describe two new species: Exanthemachrysis fresneliae V{\'e}ron sp.~nov. and Rebecca billardiae V{\'e}ron sp.~nov. Consequently, revisions of the two genera Exanthemachrysis Lepailleur emend. V{\'e}ron and Rebecca Green emend. V{\'e}ron were made. In addition, the genus Pavlova Butcher emend V{\'e}ron is revised in the light of these characters. Particular emphasis is placed on the life stages and habitat of the species.}, keywords = {habitats, haptophytes, new species, phytoplankton, pyrenoid, RCC1528, RCC1541}, issn = {2118-9773}, doi = {10.5852/ejt.2023.861.2063}, url = {https://europeanjournaloftaxonomy.eu/index.php/ejt/article/view/2063}, author = {Veron, Benoit and Rougier, Etienne and Taylor, Anthony and Goux, Didier} } @booklet {wang_novel_2023, title = {Novel dimethylsulfoniopropionate biosynthesis enzymes in diverse marine bacteria, cyanobacteria and abundant algae}, year = {2023}, month = {mar}, publisher = {In Review}, type = {preprint}, abstract = {Abstract Dimethylsulfoniopropionate (DMSP) is an abundant marine organosulfur compound[1] with roles in stress protection[2, 3], chemotaxis[4], nutrient and sulfur cycling[5] and, potentially, climate regulation[6, 7]. Marine algae and bacteria are considered significant DMSP producers, but many diverse representatives lack known DMSP synthesis genes/enzymes[8, 9]. Here, new DMSP biosynthesis enzymes were identified that considerably increase the number and diversity of potential DMSP-producing organisms, inferring new and significant global DMSP producers. A novel bifunctional DMSP biosynthesis enzyme, DsyGD, identified in the rhizobacterium Gynuella sunshinyii, produces DMSP at levels higher than any other bacterium from methylthiohydroxybutyrate (MTHB) via an N-terminal MTHB S-methyltransferase domain (termed DsyG) and a C-terminal dimethylsulfoniohydroxybutyrate (DMSHB) decarboxylase domain (termed DsyD, which is the first reported enzyme with this activity). DsyGD is also found in some filamentous cyanobacteria, not previously known to produce DMSP. Regulation of DMSP production and dsyGD transcription was consistent with their role in osmoprotection. Indeed, cloned dsyGD conferred osmotolerance to bacteria deficient in osmolyte production, something not previously demonstrated for any known DMSP synthesis gene, and which could be exploited for biotechnology e.g., engineering salt tolerance. DsyGD characterisation led to identification of phylogenetically distinct DsyG-like proteins, termed DSYE, with MTHB S-methyltransferase activity, in diverse and environmentally abundant Chlorophyta, Chlorachniophyta, Ochraphyta, Haptophyta and Bacillariophyta algae. These algae comprise a mix of low, high and previously unknown DMSP producers[10]. Algae containing DSYE, particularly bloom-forming Pelagophyceae species, which we showed to accumulate medium-high intracellular DMSP levels, were globally more abundant DMSP producers than Haptophyta, Dinophyta and Bacillariophyta with DSYB and/or TpMMT. This highlights the potential importance of Pelagophyceae and other DSYE containing algae in global DMSP production and sulfur cycling.}, keywords = {RCC100, RCC2956, RCC4094, RCC4422, RCC6172}, doi = {10.21203/rs.3.rs-2678769/v1}, url = {https://www.researchsquare.com/article/rs-2678769/v1}, author = {Wang, Jinyan and Zhou, Shun and Curson, Andrew and Vieira, Ana and Walsham, Keanu and Monaco, Serena and Li, Chun-Yang and Rivera, Peter Paolo and Wang, Xiao-Di and Hanwell, Libby and Zhu, Xiao-Yu and Le{\~a}o, Pedro and Lea-Smith, David J. and Zhang, Yuzhong and Zhang, Xiaohua and Todd, Jonathan} } @article {concordio-reis_novel_2023, title = {Novel exopolysaccharide produced by the marine dinoflagellate Heterocapsa AC210: Production, characterization, and biological properties}, journal = {Algal Research}, volume = {70}, year = {2023}, pages = {103014}, abstract = {Marine microalgae are promising sources of novel valuable biomolecules such as polysaccharides. In this study, the dinoflagellate Heterocapsa sp. AC210 was described as a new exopolysaccharide (EPS) producer. The cultivation and EPS production in bioreactor was evaluated for the first time in detail. The EPS was composed of seven different sugar monomers, including fucose and glucosamine, which are quite rare and have never been reported in dinoflagellates{\textquoteright} EPS. Moreover, the EPS had a high content of sulphate, which is often associated with biological properties. Cytotoxicity was accessed and the results showed that the EPS did not reduce cell viability for concentrations up to 1~g~L-1. Additionally, antioxidant and anti-inflammatory assays demonstrated that the EPS reduced by 18~\% the intracellular reactive oxygen species and decreased up to 79.3~\% and 46.2~\% of IL-8 and IL-6 secretion in keratinocytes, which supports its potential application in the cosmeceutical and biomedical fields.}, keywords = {Anti-inflammatory, Cytotoxicity, Dinoflagellates, Exopolysaccharide production, Marine microalgae, RCC1514, sp. AC210}, issn = {2211-9264}, doi = {10.1016/j.algal.2023.103014}, url = {https://www.sciencedirect.com/science/article/pii/S2211926423000474}, author = {Conc{\'o}rdio-Reis, Patr{\'\i}cia and Cardeira, Martim and Macedo, Ana Catarina and Ferreira, S{\'o}nia S. and Serra, Ana Teresa and Coimbra, Manuel A. and Amorim, Ana and Reis, Maria A. M. and Freitas, Filomena} } @booklet {barton_novel_2023, title = {A novel fluoro-electrochemical technique for classifying diverse marine nanophytoplankton}, year = {2023}, month = {apr}, publisher = {Life Sciences}, type = {preprint}, abstract = {

To broaden our understanding of pelagic ecosystem responses to environmental change, it is essential that we improve the spatio-temporal resolution of in situ monitoring of phytoplankton communities. A key challenge for existing methods is in classifying and quantifying cells within the nanophytoplankton size range (2-20{\textmu}m). This is particularly difficult when there are similarities in morphology, making visual differentiation difficult for both trained taxonomists and machine learning based approaches. Here we present a rapid fluoro-electrochemical technique for classifying nanophytoplankton, and using a library of 52 diverse strains of nanophytoplankton we assess the accuracy of this technique based on two measurements at the individual level: charge required to reduce per cell chlorophyll a fluorescence by 50\%, and cell radius. We demonstrate a high degree of accuracy overall (\>90\%) in categorising cells belonging to widely recognised key functional groups, however this is reduced when we consider the broader diversity of {\textquotedblleft}nano-phytoflagellates{\textquotedblright}. Notably, we observe that some groups, for example calcifying Isochrysidales, have much greater resilience to electrochemically driven oxidative conditions relative to others of a similar size, making them more easily categorised by the technique. The findings of this study present a promising step forward in advancing our toolkit for monitoring phytoplankton communities. We highlight that, for improved categorisation accuracy, future iterations of the method can be enhanced by measuring additional predictor variables with minimal adjustments to the set-up. In doing so, we foresee this technique being highly applicable, and potentially invaluable, for in situ classification and enumeration of the nanophytoplankton size fraction.

}, keywords = {RCC1, rcc1084, RCC1130, RCC1150, RCC1178, RCC1185, RCC1198, RCC1216, rcc1217, RCC1242, RCC1314, RCC1346, RCC1489, RCC1511, RCC1546, RCC1557, RCC1614, rcc1731, RCC191, RCC2570, RCC3598, RCC3696, RCC3776, RCC3780, RCC4207, RCC4221, RCC4273, RCC4657, RCC4660, RCC6, RCC623, RCC6516, RCC656, RCC678, RCC69, RCC74, RCC76, RCC8, RCC80, RCC81, RCC88, RCC911, RCC950}, doi = {10.1002/lom3.10572}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lom3.10572}, author = {Barton, Samuel and Yang, Minjun and Chen, Haotian and Batchelor-McAuley, Christopher and Compton, Richard and Bouman, Heather and Rickaby, Rosalind} } @article {noordally_phospho-dawn_2023, title = {A phospho-dawn of protein modification anticipates light onset in the picoeukaryote \textit{O. tauri}, journal = {Journal of Experimental Botany}, year = {2023}, month = {jul}, pages = {erad290}, abstract = {Abstract Diel regulation of protein levels and protein modification had been less studied than transcript rhythms. Here, we compare transcriptome data under light-dark cycles to partial proteome and phosphoproteome data, assayed using shotgun mass-spectrometry, from the alga Ostreococcus tauri, the smallest free-living eukaryote. 10\% of quantified proteins but two-thirds of phosphoproteins were rhythmic. Mathematical modelling showed that light-stimulated protein synthesis can account for the observed clustering of protein peaks in the daytime. Prompted by night-peaking and apparently dark-stable proteins, we also tested cultures under prolonged darkness, where the proteome changed less than under the diel cycle. Among the dark-stable proteins were prasinophyte-specific sequences that were also reported to accumulate when O. tauri formed lipid droplets. In the phosphoproteome, 39\% of rhythmic phospho-sites reached peak levels just before dawn. This anticipatory phosphorylation suggests that a clock-regulated phospho-dawn prepares green cells for daytime functions. Acid-directed and proline-directed protein phosphorylation sites were regulated in antiphase, implicating the clock-related, casein kinases 1 and 2 in phase-specific regulation, alternating with the CMGC protein kinase family. Understanding the dynamic phosphoprotein network should be facilitated by the minimal kinome and proteome of O. tauri. The data are available from ProteomeXchange, with identifiers PXD001734, PXD001735 and PXD002909.}, keywords = {RCC745}, issn = {0022-0957, 1460-2431}, doi = {10.1093/jxb/erad290}, url = {https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erad290/7229478}, author = {Noordally, Zeenat B and Hindle, Matthew M and Martin, Sarah F and Seaton, Daniel D and Simpson, T Ian and Le Bihan, Thierry and Millar, Andrew J} } @article {cho_phylogenomic_2023, title = {Phylogenomic position of genetically diverse phagotrophic stramenopile flagellates in the sediment-associated MAST-6 lineage and a potentially halotolerant placididean}, journal = {Molecular Phylogenetics and Evolution}, year = {2023}, month = {nov}, pages = {107964}, abstract = {Unlike morphologically conspicuous ochrophytes, many flagellates belonging to basally branching stramenopiles are small and often overlooked. As a result, many of these lineages are known only through molecular surveys and identified as MArine STramenopiles (MAST), and remain largely uncharacterized at the cellular or genomic level. These likely phagotrophic flagellates are not only phylogenetically diverse, but also extremely abundant in some environments, making their characterization all the more important. MAST-6 is one example of a phylogenetically distinct group that has been known to be associated with sediments, but little else is known about it. Indeed, until the present study, only a single species from this group, Pseudophyllomitus vesiculosus (Pseudophyllomitidae), has been both formally described and associated with genomic information. Here, we describe four new species including two new genera of sediment-dwelling MAST-6, Vomastramonas tehuelche gen. et sp. nov., Mastreximonas tlaamin gen. et sp. nov., one undescribed Pseudophyllomitus sp., BSC2, and a new species belonging to Placididea, the potentially halotolerant Haloplacidia sinai sp. nov. We also provide two additional bikosian transcriptomes from a public culture collection, to allow for better phylogenetic reconstructions of deep-branching stramenopiles. With the SSU rRNA sequences of the new MAST-6 species, we investigate the phylogenetic diversity of the MAST-6 group and show a high relative abundance of MAST-6 related to M. tlaamin in samples across various depths and geographical locations. Using the new MAST-6 species, we also update the phylogenomic tree of stramenopiles, particularly focusing on the paraphyly of Bigyra.}, keywords = {benthic protists, Bigyra, MAST-6, phylogenomics, Placididea, RCC1078, RCC257, Stramenopile}, issn = {1055-7903}, doi = {10.1016/j.ympev.2023.107964}, url = {https://www.sciencedirect.com/science/article/pii/S1055790323002646}, author = {Cho, Anna and Tikhonenkov, Denis V. and Lax, Gordon and Prokina, Kristina I. and Keeling, Patrick J.} } @booklet {devic_population_2023, title = {Population dynamics of the cosmopolitan eukaryotic picophytoplankton Bathycoccus during seasonal blooms in the bay of Banyuls sur Mer (North Western Mediterranean sea)}, year = {2023}, publisher = {BioRxiv}, type = {preprint}, abstract = {Abstract Although Bathycoccus is one of the most abundant picophytoplankton, little is known about the genetic diversity underlying its adaptation to ecological niches. In this study, the diversity of Bathycoccus populations during their annual bloom in the Mediterranean bay of Banyuls France was assessed by an INDEL based approach. Oxford Nanopore Technology (ONT) was used to characterise structural variants (SV) among the genomes of Bathycoccus sampled from geographically distinct regions in the world ocean. Markers derived from INDEL were validated by PCR and sequencing in the world-wide strains. These markers were then used to genotype 55 Bathycoccus strains isolated during the winter bloom 2018-2019 in Banyuls. With five markers, eight Multi Loci Genotypes (MLG) were determined, two of which represented 53\% and 29\% of the isolates. Physiological studies confirmed that isolates are phenotypically different, cells isolated in February growing better at low temperature than those isolated in December. When tested on environmental samples, two diversity markers showed a similar allele frequency in sea water as in individual Bathycoccus strains isolated at the same period. We conclude that these markers constitute a resource to identify the most abundant variant alleles in a given bloom. A follow-up on three consecutive blooms revealed differences in allele abundance during the course of a bloom, particularly at initiation, and between years. In addition to Bathycoccus prasinos , two other species of Bathycoccus were identified including the recently described species B. calidus and a novel species B. catiminus , suggesting that species diversity of the genus Bathycoccus may be underestimated.}, keywords = {RCC1613, RCC1615, RCC1868, RCC4222, RCC4752, RCC5417, RCC685}, doi = {10.1101/2023.02.09.527951}, url = {http://biorxiv.org/lookup/doi/10.1101/2023.02.09.527951}, author = {Devic, Martine and Mariac, C{\'e}dric and Verg{\'e}, Val{\'e}rie and Schatt, Philipe and Dennu, Louis and Lozano, Jean-Claude and Bouget, Fran{\c c}ois-Yves and Sabot, Fran{\c c}ois} } @article {bendif_rapid_2023, title = {Rapid diversification underlying the global dominance of a cosmopolitan phytoplankton}, journal = {The ISME Journal}, year = {2023}, note = {Publisher: Nature Publishing Group}, pages = {1{\textendash}11}, abstract = {Marine phytoplankton play important roles in the global ecosystem, with a limited number of cosmopolitan keystone species driving their biomass. Recent studies have revealed that many of these phytoplankton are complexes composed of sibling species, but little is known about the evolutionary processes underlying their formation. Gephyrocapsa huxleyi, a widely distributed and abundant unicellular marine planktonic algae, produces calcified scales (coccoliths), thereby significantly affects global biogeochemical cycles via sequestration of inorganic carbon. This species is composed of morphotypes defined by differing degrees of coccolith calcification, the evolutionary ecology of which remains unclear. Here, we report an integrated morphological, ecological and genomic survey across globally distributed G. huxleyi strains to reconstruct evolutionary relationships between morphotypes in relation to their habitats. While G. huxleyi has been considered a single cosmopolitan species, our analyses demonstrate that it has evolved to comprise at least three distinct species, which led us to formally revise the taxonomy of the G. huxleyi complex. Moreover, the first speciation event occurred before the onset of the last interglacial period (\textasciitilde140 ka), while the second followed during this interglacial. Then, further rapid diversifications occurred during the most recent ice-sheet expansion of the last glacial period and established morphotypes as dominant populations across environmental clines. These results suggest that glacial-cycle dynamics contributed to the isolation of ocean basins and the segregations of oceans fronts as extrinsic drivers of micro-evolutionary radiations in extant marine phytoplankton.}, keywords = {Microbial biooceanography, phylogenomics, population genetics, rcc1212, RCC1216, rcc1220, RCC1239, RCC1240, RCC1242, RCC1245, rcc1252, RCC1253, RCC1266, RCC1304, rcc1731, RCC1754, RCC1813, RCC1823, rcc1824, RCC1830, RCC1838, RCC1840, RCC1853, RCC1856, RCC3746, RCC4027, RCC4028, RCC4030, RCC5134, RCC5137, RCC5141, RCC6381, RCC6421, RCC6427, RCC6566, RCC6660, RCC6666, RCC911, RCC963}, issn = {1751-7370}, doi = {10.1038/s41396-023-01365-5}, url = {https://www.nature.com/articles/s41396-023-01365-5}, author = {Bendif, El Mahdi and Probert, Ian and Archontikis, Odysseas A. and Young, Jeremy R. and Beaufort, Luc and Rickaby, Rosalind E. and Filatov, Dmitry} } @article {parsy_selection_2023, title = {Selection of photosynthetic microorganisms grown in artificial saline industrial effluents with liquid digestate: From screening to consortium cultures}, journal = {Algal Research}, year = {2023}, month = {mar}, pages = {103061}, abstract = {The objective of this study was to determine the feasibility of using saline industrial streams as a culture medium to grow microalgae and cyanobacteria. Experiments were performed to determine the extent of the growth in artificial saline produced water and aquifer water supplemented with liquid digestate. Tests were performed in 96-wells microplates. Media were composed with different proportion of saline artificial produced water or aquifer water supplemented with 5\% v/v liquid digestate (final concentrations: 149{\textendash}195 mgN{\textperiodcentered}L-1, 1.5{\textendash}2.7 mgP{\textperiodcentered}L-1). Media were completed to 100 \% with artificial seawater, corresponding to final salinities of 40, 70 and 100 g{\textperiodcentered}L-1. D. salina, N. oceanica and T. suecica showed the best growth rates. They were selected to perform mixed cultures in 80 mL tubes in the same culture media. Population evolutions were followed for 19 days. Depending on salinity and industrial effluent used, different species became predominant over the two others (N. oceanica, T. suecica and D. salina. at 40, 70 and 100 g{\textperiodcentered}L-1, respectively). It appears that mixed culture is a good solution to have a biomass production during a culture process where the culture media will evolve in terms of salinity and composition.}, keywords = {Aquifer water, cyanobacteria, Liquid digestate, Microalgae, Produced water, RCC4223, RCC537, rcc752}, issn = {2211-9264}, doi = {10.1016/j.algal.2023.103061}, url = {https://www.sciencedirect.com/science/article/pii/S2211926423000942}, author = {Parsy, Aur{\'e}lien and Sambusiti, Cecilia and Baldoni-Andrey, Patrick and P{\'e}ri{\'e}, Fr{\'e}d{\'e}ric and Guyoneaud, R{\'e}my} } @article {dedman_shotgun_2023, title = {Shotgun proteomics reveals temperature-dependent regulation of major nutrient metabolism in coastal Synechococcus sp. WH5701}, journal = {Algal Research}, year = {2023}, month = {oct}, pages = {103279}, abstract = {Marine cyanobacteria are major contributors to the oceanic carbon sink and are predicted to increase in numbers in the future warmed ocean. As a result, the influence of marine cyanobacteria on marine biogeochemical cycling will likely be enhanced. Associated with elevations in temperature the ocean will undergo increased stratification, reducing supply of essential nutrients to upper phototrophic layers. It is therefore critical that we resolve the manners by which cyanobacteria respond to variations in temperature, and consequences for major nutrient metabolism which may ultimately direct global biogeochemistry and trophic transfer. In this study we use the coastal Synechococcus sp. WH5701 to examine proteomic alterations in major nutrient (C, N and P) metabolic pathways following exposure to varying temperature. In response to temperature treatments, Synechococcus displayed higher rates of growth and photosynthetic efficiency when temperatures were raised from 17 {\textdegree}C to 23 {\textdegree}C and 28 {\textdegree}C, associated with a significant \textasciitilde30{\textendash}40 \% alteration in the cellular proteome. As temperatures increased, proteomic investment towards photosynthetic machinery appeared up-regulated, whilst abundance of RuBisCO was reduced, associated with an apparent alteration in CCM composition and carbon metabolism. N demand appeared to increase in-line with temperature, associated with alterations in the GS-GOGAT pathway, likely due to increased demand for and efficiency of protein synthesis. In contrast, P demand at the highest temperature appeared reduced as investment in the ribosome declines due to improved translation efficiency, whilst luxury P-storage appeared a feature of growth at low temperature. It appears likely that as seawater temperatures rise under ocean warming, the biochemical composition of cyanobacteria will be altered, increasing cellular C- and N- to P ratios, ultimately impacting upon their contribution to oceanic biogeochemical cycling.}, keywords = {climate change, Ocean warming, phytoplankton, Proteomics: Marine biogeochemistry, rcc1084}, issn = {2211-9264}, doi = {10.1016/j.algal.2023.103279}, url = {https://www.sciencedirect.com/science/article/pii/S2211926423003120}, author = {Dedman, Craig J. and Barton, Samuel and Fournier, Marjorie and Rickaby, Rosalind E. M.} } @article {klintzsch_stable_2023, title = {Stable Carbon Isotope Signature of Methane Released from Phytoplankton}, journal = {Geophysical Research Letters}, year = {2023}, month = {feb}, abstract = {Aquatic ecosystems play an important role in global methane cycling and many field studies have reported methane supersaturation in the oxic surface mixed layer (SML) of the ocean and in the epilimnion of lakes. The origin of methane formed under oxic condition is hotly debated and several pathways have recently been offered to explain the {\textquoteleft}methane paradox{\textquoteright}. In this context, stable isotope measurements have been applied to constrain methane sources in supersaturated oxygenated waters. Here we present stable carbon isotope signatures for six widespread marine phytoplankton species, three haptophyte algae and three cyanobacteria, incubated under laboratory conditions. The observed isotopic patterns implicate that methane formed by phytoplankton might be clearly distinguished from methane produced by methanogenic archaea. Comparing results from phytoplankton experiments with isotopic data from field measurements, suggests that algal and cyanobacterial populations may contribute substantially to methane formation observed in the SML of oceans and lakes.}, keywords = {RCC1216, ⛔ No DOI found}, doi = {10.22541/essoar.167689993.32180072/v1}, url = {https://essopenarchive.org/users/587513/articles/625160-stable-carbon-isotope-signature-of-methane-released-from-phytoplankton?commit=633a121ee07c48e6c59ffeca06fd5d5ebe1df4d4}, author = {Klintzsch, Thomas and Geisinger, Hannah and Wieland, Anna and Langer, Gerald and Nehrke, Gernot and Bizic, Mina and Greule, Markus and Lenhart, Katharina and Borsch, Christian and Schroll, Moritz and Keppler, Frank} } @article {zhang_stimulating_2023, title = {Stimulating and toxic effect of chromium on growth and photosynthesis of a marine chlorophyte}, journal = {New Phytologist}, volume = {n/a}, number = {n/a}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/nph.19376}, abstract = {Marine phytoplankton can interchange trace metals in various biochemical functions, particularly under metal-limiting conditions. Here, we investigate the stimulating and toxicity effect of chromium (Cr) on a marine Chlorophyceae Osetreococcus tauri under Fe-replete and Fe-deficient conditions. We determined the growth, photosynthesis, and proteome expressions of Osetreococcus tauri cultured under different Cr and Fe concentrations. In Fe-replete conditions, the presence of Cr(VI) stimulated significantly the growth rate and the maximum yield of photochemistry of photosystem II (Fv/Fm) of the phytoplankton, while the functional absorption cross-section of photosystem II (σPSII) did not change. Minor additions of Cr(VI) partially rescued phytoplankton growth under Fe-limited conditions. Proteomic analysis of this alga grown in Fe-replete normal and Fe-replete with Cr addition media (10 μM Cr) showed that the presence of Cr significantly decreased the expression of phosphate-transporting proteins and photosynthetic proteins, while increasing the expression of proteins related to carbon assimilation. Cr can stimulate the growth and photosynthesis of O. tauri, but the effects are dependent on both the Cr(VI) concentration and the availability of Fe. The proteomic results further suggest that Cr(VI) addition might significantly increase starch production and carbon fixation.}, keywords = {chromium, Photosynthesis, phytoplankton, proteomics, RCC1, RCC1242, trace metal}, issn = {1469-8137}, doi = {10.1111/nph.19376}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.19376}, author = {Zhang, Qiong and Charles, Philip D. and Bendif, El Mahdi and Hester, Svenja S. and Mohammad, Shabaz and Rickaby, Rosalind E. M.} } @article {storti_tailoring_2023, title = {Tailoring confocal microscopy for real-time analysis of photosynthesis at single-cell resolution}, journal = {Cell Reports Methods}, year = {2023}, pages = {100568}, abstract = {Photoautotrophs{\textquoteright} environmental responses have been extensively studied at the organism and ecosystem level. However, less is known about their photosynthesis at the single-cell level. This information is needed to understand photosynthetic acclimation processes, as light changes as it penetrates cells, layers of cells, or organs. Furthermore, cells within the same tissue may behave differently, being at different developmental/ physiological stages. Here, we describe an approach for single-cell and subcellular photophysiology based on the customization of confocal microscopy to assess chlorophyll fluorescence quenching by the saturation pulse method. We exploit this setup to (1) reassess the specialization of photosynthetic activities in developing tissues of non-vascular plants; (2) identify a specific subpopulation of phytoplankton cells in marine photosymbiosis, which consolidate energetic connections with their hosts; and (3) examine the link between light penetration and photoprotection responses inside the different tissues that constitute a plant leaf anatomy.}, keywords = {rcc1383}, issn = {26672375}, doi = {10.1016/j.crmeth.2023.100568}, url = {https://linkinghub.elsevier.com/retrieve/pii/S2667237523002126}, author = {Storti, Mattia and Hsine, Haythem and Uwizeye, Clarisse and Bastien, Olivier and Yee, Daniel P. and Chevalier, Fabien and Decelle, Johan and Giustini, C{\'e}cile and B{\'e}al, Daniel and Curien, Gilles and Finazzi, Giovanni and Tolleter, Dimitri} } @booklet {blocka_taxonomic_2023, title = {Taxonomic profling of microbes co-cultured with protists in the Roscoff Culture Collection}, year = {2023}, publisher = {ETH Z{\"u}rich}, type = {Semester Project Report}, abstract = {The ocean hosts an enormous diversity of microorganisms. However, most of these are notat present available for culture, which makes them difcult to study. We know that manymarine organisms rely on complex nutrient cycles which are difcult to unravel. Microalgaeproduces soluble carbon-, sulfur-, and nitrogen-containing compounds which are taken up byheterotrophic bacteria. The photosynthesizers, on the other hand, often rely on co-factors ofbacterial origin, such as vitamin B12. Since many ocean bacteria may rely on algal organicproducts to obtain essential nutrients, searching for microbes of interest in algal strain culturescan help pinpoint the method of cultivation. In this study, 16S meta-barcoding was performedon bacteria associated to sixty strains from the Roscoff Culture Collection. The bacterial taxonomic composition differed between the algal divisions. Hierarchical clustering revealed interand intra-division differences. The microbiota of the samples mostly belonged to Bacteroidota,Alpha- and Gammaproteobacteria. This is consistent with previous studies on the cycling ofnutrients in the ocean, as these groups are metabolically flexible and ubiquitous heterotrophs.Among the sequenced reads, there appear members of poorly described or undescribed prokaryotic lineages at high taxonomic levels, which could be subject to further study and cultivationefforts. Obtaining these organisms in pure culture could allow the description of new lineagesand their unique metabolisms, and potentially, the production of their bio-products of interest.}, author = {Blocka, Zuzanna} } @article {barbeyron_zobellia_2023, title = {\textit{Zobellia alginiliquefaciens sp. nov., a novel member of the flavobacteria isolated from the epibiota of the brown alga Ericaria zosteroides (C. Agardh) Molinari \& Guiry 2020}, journal = {International Journal of Systematic and Evolutionary Microbiology}, volume = {73}, number = {6}, year = {2023}, note = {Publisher: Microbiology Society,}, pages = {005924}, abstract = {Strain LLG6346-3.1T, isolated from the thallus of the brown alga Ericaria zosteroides collected from the Mediterranean Sea near Bastia in Corsica, France, was characterised using a polyphasic method. Cells were Gram-stain-negative, strictly aerobic, non-flagellated, motile by gliding, rod-shaped and grew optimally at 30{\textendash}33 {\textdegree}C, at pH 8{\textendash}8.5 and with 4{\textendash}5 \% NaCl. LLG6346-3.1T used the seaweed polysaccharide alginic acid as a sole carbon source which was vigorously liquefied. The results of phylogenetic analyses indicated that the bacterium is affiliated to the genus Zobellia (family Flavobacteriaceae , class Flavobacteriia ). LLG6346-3.1T exhibited 16S rRNA gene sequence similarity values of 98.6 and 98.3 \% to the type strains of Zobellia russellii and Zobellia roscoffensis , respectively, and of 97.4{\textendash}98.5 \% to members of other species of the genus Zobellia . The DNA G+C content of LLG6346-3.1T was determined to be 38.3 mol\%. Digital DNA{\textendash}DNA hybridisation predictions by the average nucleotide identity (ANI) and genome to genome distance calculator (GGDC) methods between LLG6346-3.1T and other members of the genus Zobellia showed values of 76{\textendash}88 \% and below 37 \%, respectively. The results of phenotypic, phylogenetic and genomic analyses indicate that LLG6346-3.1T is distinct from species of the genus Zobellia with validly published names and that it represents a novel species of the genus Zobellia , for which the name Zobellia alginiliquefaciens sp. nov. is proposed. The type strain is LLG6346-3.1T (= RCC7657T = LMG 32918T).}, keywords = {RCC7657}, issn = {1466-5034}, doi = {10.1099/ijsem.0.005924}, url = {https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.005924}, author = {Barbeyron, Tristan and Le Duff, Nolwen and Duchaud, Eric and Thomas, Fran{\c c}ois} } @article {alonso-saez_transcriptional_2023, title = {Transcriptional Mechanisms of Thermal Acclimation in \textit{Prochlorococcus}, journal = {mBio}, year = {2023}, pages = {e03425{\textendash}22}, abstract = {Low temperature limits the growth and the distribution of the key oceanic primary producer Prochlorococcus, which does not proliferate above a latitude of ca. 40{\textdegree}. Yet, the molecular basis of thermal acclimation in this cyanobacterium remains unexplored. We analyzed the transcriptional response of the Prochlorococcus marinus strain MIT9301 in long-term acclimations and in natural Prochlorococcus populations along a temperature range enabling its growth (17 to 30{\textdegree}C). MIT9301 upregulated mechanisms of the global stress response at the temperature minimum (17{\textdegree}C) but maintained the expression levels of genes involved in essential metabolic pathways (e.g., ATP synthesis and carbon fixation) along the whole thermal niche. Notably, the declining growth of MIT9301 from the optimum to the minimum temperature was coincident with a transcriptional suppression of the photosynthetic apparatus and a dampening of its circadian expression patterns, indicating a loss in their regulatory capacity under cold conditions. Under warm conditions, the cellular transcript inventory of MIT9301 was strongly streamlined, which may also induce regulatory imbalances due to stochasticity in gene expression. The daytime transcriptional suppression of photosynthetic genes at low temperature was also observed in metatranscriptomic reads mapping to MIT9301 across the global ocean, implying that this molecular mechanism may be associated with the restricted distribution of Prochlorococcus to temperate zones.}, keywords = {RCC3377}, issn = {2150-7511}, doi = {10.1128/mbio.03425-22}, url = {https://journals.asm.org/doi/10.1128/mbio.03425-22}, author = {Alonso-S{\'a}ez, Laura and Palacio, Antonio S. and Cabello, Ana M. and Robaina-Est{\'e}vez, Semid{\'a}n and Gonz{\'a}lez, Jos{\'e} M. and Garczarek, Laurence and L{\'o}pez-Urrutia, {\'A}ngel}, editor = {Martiny, Jennifer B. H.} } @article {syhapanha_transcriptomicsguided_2023, title = {Transcriptomics-guided identification of an algicidal protease of the marine bacterium Kordia algicida OT-1}, journal = {MicrobiologyOpen}, volume = {12}, number = {5}, year = {2023}, pages = {e1387}, abstract = {In recent years, interest in algicidal bacteria has risen due to their ecological importance and their potential as biotic regulators of harmful algal blooms. Algicidal bacteria shape the plankton communities of the oceans by inhibiting or lysing microalgae and by consuming the released nutrients. Kordia algicida strain OT-1 is a model marine algicidal bacterium that was isolated from a bloom of the diatom Skeletonema costatum. Previous work has suggested that algicidal activity is mediated by secreted proteases. Here, we utilize a transcriptomics-guided approach to identify the serine protease gene KAOT1_RS09515, hereby named alpA1 as a key element in the algicidal activity of K. algicida. The protease AlpA1 was expressed and purified from a heterologous host and used in in vitro bioassays to validate its activity. We also show that K. algicida is the only algicidal species within a group of four members of the Kordia genus. The identification of this algicidal protease opens the possibility of real-time monitoring of the ecological impact of algicidal bacteria in natural phytoplankton blooms., Algicidal bacteria shape the plankton communities of the oceans by lysing microalgae and consuming the released nutrients. Kordia algicida is an environmentally relevant marine bacterium whose algicidal activity is mediated by secreted proteases. In this study, we utilize a transcriptomics-guided approach to identify the secreted serine protease AlpA1 as a key factor in the algicidal process. This discovery offers new approaches for the real-time monitoring and manipulation of algicidal bacteria in algal blooms.}, keywords = {RCC75}, issn = {2045-8827}, doi = {10.1002/mbo3.1387}, url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10565126/}, author = {Syhapanha, Kristy S. and Russo, David A. and Deng, Yun and Meyer, Nils and Poulin, Remington X. and Pohnert, Georg} } @article {bordiga_unexpected_2023, title = {Unexpected silicon localization in calcium carbonate exoskeleton of cultured and fossil coccolithophores}, journal = {Scientific Reports}, volume = {13}, number = {1}, year = {2023}, note = {Number: 1 Publisher: Nature Publishing Group}, month = {may}, pages = {7417}, abstract = {Coccolithophores, marine calcifying phytoplankton, are important primary producers impacting the global carbon cycle at different timescales. Their biomineral structures, the calcite containing coccoliths, are among the most elaborate hard parts of any organism. Understanding the morphogenesis of coccoliths is not only relevant in the context of coccolithophore eco-physiology but will also inform biomineralization and crystal design research more generally. The recent discovery of a silicon (Si) requirement for crystal shaping in some coccolithophores has opened up a new avenue of biomineralization research. In order to develop a mechanistic understanding of the role of Si, the presence and localization of this chemical element in coccoliths needs to be known. Here, we document for the first time the uneven Si distribution in Helicosphaera carteri coccoliths through three synchrotron-based techniques employing X-ray Fluorescence and Infrared Spectromicroscopy. The enrichment of Si in specific areas of the coccoliths point to a targeted role of this element in the coccolith formation. Our findings mark a key step in biomineralization research because it opens the door for a detailed mechanistic understanding of the role Si plays in shaping coccolith crystals.}, keywords = {Biogeochemistry, Marine biology, Palaeontology, RCC1323}, issn = {2045-2322}, doi = {10.1038/s41598-023-34003-3}, url = {https://www.nature.com/articles/s41598-023-34003-3}, author = {Bordiga, M. and Lupi, C. and Langer, G. and Gianoncelli, A. and Birarda, G. and Pollastri, S. and Bonanni, V. and Bedolla, D. E. and Vaccari, L. and Gariani, G. and Cerino, F. and Cabrini, M. and Beran, A. and Zuccotti, M. and Fiorentino, G. and Zanoni, M. and Garagna, S. and Cobianchi, M. and Di Giulio, A.} } @article {walde_viral_2023, title = {Viral infection impacts the 3D subcellular structure of the abundant marine diatom Guinardia delicatula}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2023}, abstract = {Viruses are key players in marine ecosystems where they infect abundant marine microbes. RNA viruses are emerging as key members of the marine virosphere. They have recently been identified as a potential source of mortality in diatoms, a group of microalgae that accounts for roughly 40\% of the primary production in the ocean. Despite their likely importance, their impacts on host populations and ecosystems remain difficult to assess. In this study, we introduce an innovative approach that combines automated 3D confocal microscopy with quantitative image analysis and physiological measurements to expand our understanding of viral infection. We followed different stages of infection of the bloom-forming diatom Guinardia delicatula by the RNA virus GdelRNAV-04 until the complete lysis of the host. From 20h after infection, we observed quantifiable changes in subcellular host morphology and biomass. Our microscopy monitoring also showed that viral infection of G. delicatula induced the formation of auxospores as a probable defense strategy against viruses. Our method enables the detection of discriminative morphological features on the subcellular scale and at high throughput for comparing populations, making it a promising approach for the quantification of viral infections in the field in the future.}, keywords = {RCC3083, RCC5812}, issn = {2296-7745}, doi = {10.3389/fmars.2022.1034235}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.1034235}, author = {Walde, Marie and Camplong, Cyprien and de Vargas, Colomban and Baudoux, Anne-claire and Simon, Nathalie} } @article {yee_v-type_2023, title = {The V-type ATPase enhances photosynthesis in marine phytoplankton and further links phagocytosis to symbiogenesis}, journal = {Current Biology}, year = {2023}, month = {may}, pages = {S0960982223006152}, abstract = {Diatoms, dinoflagellates, and coccolithophores are dominant groups of marine eukaryotic phytoplankton that are collectively responsible for the majority of primary production in the ocean.1 These phytoplankton contain additional intracellular membranes around their chloroplasts, which are derived from ancestral engulfment of red microalgae by unicellular heterotrophic eukaryotes that led to secondary and tertiary endosymbiosis.2 However, the selectable evolutionary advantage of these membranes and the physiological significance for extant phytoplankton remain poorly understood. Since intracellular digestive vacuoles are ubiquitously acidified by V-type H+-ATPase (VHA),3 proton pumps were proposed to acidify the microenvironment around secondary chloroplasts to promote the dehydration of dissolved inorganic carbon (DIC) into CO2, thus enhancing photosynthesis.4,5 We report that VHA is localized around the chloroplasts of centric diatoms and that VHA significantly contributes to their photosynthesis across a wide range of oceanic irradiances. Similar results in a pennate diatom, dinoflagellate, and coccolithophore, but not green or red microalgae, imply the co-option of phagocytic VHA activity into a carbon-concentrating mechanism (CCM) is common to secondary endosymbiotic phytoplankton. Furthermore, analogous mechanisms in extant photosymbiotic marine invertebrates6{\textendash}8 provide functional evidence for an adaptive advantage throughout the transition from endosymbiosis to symbiogenesis. Based on the contribution of diatoms to ocean biogeochemical cycles, VHA-mediated enhancement of photosynthesis contributes at least 3.5 Gtons of fixed carbon per year (or 7\% of primary production in the ocean), providing an example of a symbiosis-derived evolutionary innovation with global environmental implications.}, keywords = {RCC3387}, issn = {09609822}, doi = {10.1016/j.cub.2023.05.020}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0960982223006152}, author = {Yee, Daniel P. and Samo, Ty J. and Abbriano, Raffaela M. and Shimasaki, Bethany and Vernet, Maria and Mayali, Xavier and Weber, Peter K. and Mitchell, B. Greg and Hildebrand, Mark and Decelle, Johan and Tresguerres, Martin} } @article {jang_assessment_2022, title = {Assessment of biodiversity, global distribution, and putative ecological niches of suessiacean dinoflagellates by DNA metabarcoding}, journal = {Frontiers in Ecology and Evolution}, volume = {10}, year = {2022}, abstract = {Dinoflagellates in the family Suessiaceae, so-called suessiacean dinoflagellates, play diverse roles in aquatic ecosystems, being distributed from tropical to polar waters and from marine to freshwater habitats and encompassing free-living forms, symbionts, and parasites. Despite their importance due to the variety of ecological roles and biodiversity, very few studies have characterized small suessiacean species. Recent advances in molecular techniques could provide insights into the yet unexplored ecological roles they play in aquatic environments. Using a global DNA metabarcoding dataset, this study elucidated the hidden biodiversity, global distribution, and ecological characteristics of suessiacean dinoflagellates. The results of this study indicated that the family Suessiaceae was the sixth highest in terms of read count and the ninth highest in terms of amplicon sequence variant (ASV) richness from a total of 42 categorized dinoflagellate families, suggesting that their global abundance has been greatly underestimated. Furthermore, metabarcodes of suessiacean dinoflagellates were found to be cosmopolitan in distribution, although the ecological niche of each taxon was distinctly different within the group based on their latitudinal and vertical distribution patterns. Moreover, phylogenetic analysis discovered at least five new phylogenetic groups and three new individual species within the family. Collectively, the findings of this study highlight the significance of suessiacean dinoflagellates in global aquatic ecosystems and reveal the importance of big data obtained from environmental DNA in exploring the ecological functions of understudied species.}, keywords = {RCC2013}, issn = {2296-701X}, doi = {10.3389/fevo.2022.1010854}, url = {https://www.frontiersin.org/articles/10.3389/fevo.2022.1010854}, author = {Jang, Se Hyeon} } @article {sucheras-marx_coccolith_2022, title = {Coccolith size rules {\textendash} What controls the size of coccoliths during coccolithogenesis?}, journal = {Marine Micropaleontology}, volume = {170}, year = {2022}, pages = {102080}, abstract = {Heterococcoliths are calcite platelets produced inside diploid coccolithophore cells and extruded to form a covering on the cell surface called a coccosphere. The size of coccoliths is an important parameter sometimes used to identify species, and it is observed to be influenced in extant species by abiotic parameters (e.g., CO2, light). However, the variable distribution of coccolith sizes occurring within a single coccosphere questions the mechanisms controlling coccolith size. A relationship between cell/coccosphere size and mean coccolith size was previously identified, called the {\textquotedblleft}coccolithophore size rules{\textquotedblright}. In this study, we query the mechanisms controlling the size of a coccolith during coccolithogenesis. A culture experiment on Gephyrocapsa huxleyi strain RCC1216 shows that coccolithogenesis occurs during the cell growth G1 interphase and newly produced coccoliths get bigger as the cell grows. These observations provide parameters for the development of two numerical models used to simulate the coccolith size distribution within a coccolithophore population. Neither model can accurately reproduce an empirical monoclonal coccolith size distribution, indicating that additional factors influence coccolith size. According to our results, coccolith size is only clearly related to cell size at the time of its formation. We confirm that application of the coccolithophore size rules model should be limited to inferring average cell dimensions from (fossil) coccolith biometry, and that comparisons are valid only in multipopulational studies. The coccolith size rule model {\textendash} the constraining effect of coccolith production during G1 interphase cell growth on coccolith size {\textendash} proposed here is applicable only for some placolith-forming species.}, keywords = {Biometry, coccolith, coccolithophore, life cycle, RCC1216, Size variation}, issn = {0377-8398}, doi = {10.1016/j.marmicro.2021.102080}, url = {https://www.sciencedirect.com/science/article/pii/S0377839821001213}, author = {Such{\'e}ras-Marx, Baptiste and Viseur, Sophie and Walker, Charlotte E. and Beaufort, Luc and Probert, Ian and Bolton, Clara} } @article {ferrieux_comparative_2022, title = {Comparative Thermophysiology of Marine Synechococcus CRD1 Strains Isolated From Different Thermal Niches in Iron-Depleted Areas}, journal = {Frontiers in Microbiology}, volume = {13}, year = {2022}, abstract = {Marine Synechococcus cyanobacteria are ubiquitous in the ocean, a feature likely related to their extensive genetic diversity. Amongst the major lineages, clades I and IV preferentially thrive in temperate and cold, nutrient-rich waters, whilst clades II and III prefer warm, nitrogen or phosphorus-depleted waters. The existence of such cold (I/IV) and warm (II/III) thermotypes is corroborated by physiological characterization of representative strains. A fifth clade, CRD1, was recently shown to dominate the Synechococcus community in iron-depleted areas of the world ocean and to encompass three distinct ecologically significant taxonomic units (ESTUs CRD1A-C) occupying different thermal niches, suggesting that distinct thermotypes could also occur within this clade. Here, using comparative thermophysiology of strains representative of these three CRD1 ESTUs we show that the CRD1A strain MITS9220 is a warm thermotype, the CRD1B strain BIOS-U3-1 a cold temperate thermotype, and the CRD1C strain BIOS-E4-1 a warm temperate stenotherm. Curiously, the CRD1B thermotype lacks traits and/or genomic features typical of cold thermotypes. In contrast, we found specific physiological traits of the CRD1 strains compared to their clade I, II, III, and IV counterparts, including a lower growth rate and photosystem II maximal quantum yield at most temperatures and a higher turnover rate of the D1 protein. Together, our data suggests that the CRD1 clade prioritizes adaptation to low-iron conditions over temperature adaptation, even though the occurrence of several CRD1 thermotypes likely explains why the CRD1 clade as a whole occupies most iron-limited waters.}, keywords = {RCC2374, RCC2385, RCC2533, RCC2534, RCC2571, RCC515, rcc539, rcc791}, issn = {1664-302X}, doi = {10.3389/fmicb.2022.893413}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2022.893413}, author = {Ferrieux, Mathilde and Dufour, Louison and Dor{\'e}, Hugo and Ratin, Morgane and Gu{\'e}neugu{\`e}s, Audrey and Chasselin, L{\'e}o and Marie, Dominique and Rigaut-jalabert, Fabienne and Le Gall, Florence and Sciandra, Th{\'e}o and Monier, Garance and Hoebeke, Mark and Corre, Erwan and Xia, Xiaomin and Liu, Hongbin and Scanlan, David J. and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence} } @article {yung_diversity_2022, title = {Diversity and Evolution of Mamiellophyceae: Early-Diverging Phytoplanktonic Green Algae Containing Many Cosmopolitan Species}, journal = {Journal of Marine Science and Engineering}, volume = {10}, number = {2}, year = {2022}, note = {Number: 2 Publisher: Multidisciplinary Digital Publishing Institute}, month = {feb}, pages = {240}, abstract = {The genomic revolution has bridged a gap in our knowledge about the diversity, biology and evolution of unicellular photosynthetic eukaryotes, which bear very few discriminating morphological features among species from the same genus. The high-quality genome resources available in the class Mamiellophyceae (Chlorophyta) have been paramount to estimate species diversity and screen available metagenomic data to assess the biogeography and ecological niches of different species on a global scale. Here we review the current knowledge about the diversity, ecology and evolution of the Mamiellophyceae and the large double-stranded DNA prasinoviruses infecting them, brought by the combination of genomic and metagenomic analyses, including 26 metabarcoding environmental studies, as well as the pan-oceanic GOS and the Tara Oceans expeditions.}, keywords = {Biogeography, evolution, genomics, mamiellophyceae, metagenomics, microalgae{\textendash}virus interactions, phycoDNAvirus, RCC809}, issn = {2077-1312}, doi = {10.3390/jmse10020240}, url = {https://www.mdpi.com/2077-1312/10/2/240}, author = {Yung, Charmaine C. M. and Rey Redondo, Elvira and Sanchez, Fr{\'e}d{\'e}ric and Yau, Sheree and Piganeau, Gwenael} } @article {grebert_diversity_2022, title = {Diversity and evolution of pigment types in marine \textit{Synechococcus cyanobacteria}, journal = {Genome Biology and Evolution}, year = {2022}, pages = {evac035}, abstract = {DNA integration and site-specific recombination, suggesting that their genomic variability relies D in part on a {\textquoteleft}tycheposon{\textquoteright}-like mechanism. Comparison of the phylogenies obtained for PBS and E core genes revealed that the evolutionary history of PBS rod genes differs from the core T genome and is characterized by the co-existence of different alleles and frequent allelic P exchange. We propose a scenario for the evolution of the different pigment types and highlight E the importance of incomplete lineage sorting in maintaining a wide diversity of pigment types in C different Synechococcus lineages despite multiple speciation events.}, keywords = {RCC307, to add}, issn = {1759-6653}, doi = {10.1093/gbe/evac035}, url = {https://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evac035/6547267}, author = {Gr{\'e}bert, Th{\'e}ophile and Garczarek, Laurence and Daubin, Vincent and Humily, Florian and Marie, Dominique and Ratin, Morgane and Devailly, Alban and Farrant, Gregory K. and Mary, Isabelle and Mella-Flores, Daniella and Tanguy, Gwenn and Labadie, Karine and Wincker, Patrick and Kehoe, David M. and Partensky, Fr{\'e}d{\'e}ric}, editor = {Angert, Esther} } @article {sorokina_draft_2022, title = {Draft genome assembly and sequencing dataset of the marine diatom Skeletonema costatum RCC75}, journal = {Data in Brief}, year = {2022}, month = {feb}, pages = {107931}, abstract = {Diatoms (Bacillariophyceae) are a major constituent of the phytoplankton and have a universally recognized ecological importance. Between 1,000 and 1,300 diatom genera have been described in the literature, but only 10 nuclear genomes have been published and made available to the public up to date. Skeletonema costatum is a cosmopolitan marine diatom, principally occurring in coastal regions, and is one of the most abundant members of the Skeletonema genus. Here we present a draft assembly of the Skeletonema costatum RCC75 genome, obtained from PacBio and Illumina NovaSeq data. This dataset will expand the knowledge of the Bacillariophyceae genetics and contribute to the global understanding of phytoplankton{\textquoteright}s physiological, ecological, and environmental functioning.}, keywords = {Algal genome, BACILLARIOPHYCEAE, diatoms, genome sequencing, Illumina sequencing, PacBio sequencing, RCC75}, issn = {2352-3409}, doi = {10.1016/j.dib.2022.107931}, url = {https://www.sciencedirect.com/science/article/pii/S2352340922001433}, author = {Sorokina, Maria and Barth, Emanuel and Zulfiqar, Mahnoor and Kwantes, Michiel and Pohnert, Georg and Steinbeck, Christoph} } @article {fernandes_effects_2022, title = {Effects of phosphorus-induced changes on the growth, nitrogen uptake, and biochemical composition of Pavlova pinguis and Hemiselmis cf. andersenii}, journal = {Journal of Applied Phycology}, year = {2022}, abstract = {The understanding of the phosphorus-induced changes in the biochemical composition of microalgae is of great importance for achieving efficiency in high-value lipid production. To study the chemoplasticity of Pavlova pinguis (Haptophyceae) and Hemiselmis cf. andersenii (Cryptophyceae), their growth, carotenoid and chlorophyll a content, and their monosaccharide and lipid profiles were analyzed against several phosphorus (P) regimes: low (LP), medium (MP), and high (HP). For both microalgal cultures, increasing initial P concentrations showed a positive effect on biomass productivities. Carbon-rich pools presented significant differences (p< 0.05) for P. pinguis against P treatments, in contrast to H. cf. andersenii. Differential responses to P-induced changes in microalgae monosaccharide and lipid profile were observed. Hemiselmis cf. andersenii increased its proportion in galactose (up to 3 times) from LP to HP conditions, whereas P. pinguis decreased (up to 20\%) its glucose proportion from LP to HP conditions. For P. pinguis, the lowest amount (13.12 mg g-1 dw) of sterols was observed at LP conditions, in contrast to its carotenoid content (4.32 mg g-1 dw). P-replete conditions were the most effective in inducing high-value lipid accumulation. Non-targeted lipid analysis revealed which samples would need to be processed to fully exploit its high-value lipids, namely H. cf andersenii under MP and HP conditions. This study demonstrated that P played an important role in carbon allocation, nitrogen uptake, and lipid regulation on P. pinguis and H. cf. andersenii, and that P-replete conditions could be useful for optimizing high-value lipids with potential for nutraceutical and pharmaceutical fields.}, keywords = {RCC1539}, issn = {1573-5176}, doi = {10.1007/s10811-021-02662-2}, url = {https://doi.org/10.1007/s10811-021-02662-2}, author = {Fernandes, Tom{\'a}sia and Cordeiro, Nereida} } @article {ebenezer_elemental_2022, title = {Elemental and macromolecular composition of the marine Chloropicophyceae, a major group of oceanic photosynthetic picoeukaryotes}, journal = {Limnology and Oceanography}, volume = {n/a}, number = {n/a}, year = {2022}, note = {_eprint: https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.12013}, abstract = {Chloropicophyceae (Prasinophyte Clade VII) are small nonmotile coccoid cells with cell diameters ranging from 1 to 3 μm. Molecular surveys indicate they are relatively high in abundance in moderately oligotrophic oceanic waters and may substantively contribute to biogeochemical cycling in the sea. Here, we quantify the elemental and macromolecular composition of three subtropical Chloropicophyceae strains: Chloropicon mariensis, Chloropicon maureeniae, and Chloropicon roscoffensis under nutrient-sufficient exponential growth and nitrate starvation. Under nutrient-sufficient conditions the Chloropicophyceae are high in C : N and quite low in C : P and N : P relative to the canonical Redfield ratio, reflecting their relatively high nucleic acid composition compared to many other phytoplankton taxa. Nitrate starvation causes increases in C : N and C : P and decreases in N : P, primarily due to increases in carbohydrate and lipid and decreases in protein and RNA. There is genetic evidence that unlike most other green algae, Chloropicophyceae are diploid. The high nucleic acid content in the Chloropicon is consistent with the hypothesis that the nucleus, as a nonscalable component, takes up a larger and substantial proportion of cell mass in diploid picoeukaryotes. The elemental and macromolecular composition of these Chloropicophyceae, and relatively homeostatic response to N-starvation compared to diatoms, provides some insight into their success in the moderately oligotrophic ocean.}, keywords = {RCC138, RCC3374, RCC3375}, issn = {1939-5590}, doi = {10.1002/lno.12013}, url = {http://onlinelibrary.wiley.com/doi/abs/10.1002/lno.12013}, author = {Ebenezer, Vinitha and Hu, Yingyu and Carnicer, Olga and Irwin, Andrew J. and Follows, Michael J. and Finkel, Zoe V.} } @article {leblond_galactolipids_2022, title = {Galactolipids of the genus Amphidinium (Dinophyceae): an hypothesis that they are basal to those of other peridinin-containing dinoflagellates}, journal = {European Journal of Phycology}, year = {2022}, note = {Publisher: Taylor \& Francis _eprint: https://doi.org/10.1080/09670262.2022.2092215}, pages = {1{\textendash}10}, abstract = {The genus Amphidinium is shown in many phylogenies to be basal to other peridinin-containing, photosynthetic dinoflagellates as one of the first photosynthetic genera to arise after the evolution of heterotrophic genera. As part of our continuing examination of the plastid-associated galactolipids, namely mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively), in dinoflagellates, we here examine the galactolipid composition of members of the genus Amphidinium. We show that this genus is characterized by an abundance of 20:5(n-3)/18:5(n-3) and 20:5(n-3)/18:4(n-3) forms of MGDG and DGDG (with sn-1/sn-2 regiochemical specificity of fatty acids), but also sometimes with generally lesser amounts of some polyunsaturated C18/C18 forms, thus placing the examined species within a previously identified cluster of C20/C18 MGDG- and DGDG-containing, peridinin-containing dinoflagellates. We also show that Testudodinium testudo, previously known as Amphidinium testudo, conversely falls within a previously identified C18/C18 cluster, indicating a distinct difference in galactolipid biosynthesis capability. While it is likely that further revision of the genus may occur in the future and/or more basal peridinin-containing, photosynthetic genera may be discovered, at the current time Amphidinium is the currently agreed-upon most basal dinoflagellate genus for which isolates are available for biochemical characterization such as what we describe in this paper. Thus, because of the presumed basal position of the genus Amphidinium, we present a hypothesis that its galactolipids currently represent those that are ancestral to other genera of peridinin-containing dinoflagellates, including those within the C18/C18 cluster.}, keywords = {Amphidinium, chloroplast, Dinoflagellate, Dinophyceae, lipid, RCC1981, Testudodinium}, issn = {0967-0262}, doi = {10.1080/09670262.2022.2092215}, url = {https://doi.org/10.1080/09670262.2022.2092215}, author = {Leblond, Jeffrey D. and Elkins, Lindsey C. and Graeff, Jori E. and Sabir, Kyra} } @article {guerin_genomic_2022, title = {Genomic adaptation of the picoeukaryote Pelagomonas calceolata to iron-poor oceans revealed by a chromosome-scale genome sequence}, journal = {Communications Biology}, volume = {5}, number = {1}, year = {2022}, note = {Number: 1 Publisher: Nature Publishing Group}, pages = {1{\textendash}14}, abstract = {The smallest phytoplankton species are key actors in oceans biogeochemical cycling and their abundance and distribution are affected with global environmental changes. Among them, algae of the Pelagophyceae class encompass coastal species causative of harmful algal blooms while others are cosmopolitan and abundant. The lack of genomic reference in this lineage is a main limitation to study its ecological importance. Here, we analysed Pelagomonas calceolata relative abundance, ecological niche and potential for the adaptation in all oceans using a complete chromosome-scale assembled genome sequence. Our results show that P. calceolata is one of the most abundant eukaryotic species in the oceans with a relative abundance favoured by high temperature, low-light and iron-poor conditions. Climate change projections based on its relative abundance suggest an extension of the P. calceolata habitat toward the poles at the end of this century. Finally, we observed a specific gene repertoire and expression level variations potentially explaining its ecological success in low-iron and low-nitrate environments. Collectively, these findings reveal the ecological importance of P. calceolata and lay the foundation for a global scale analysis of the adaptation and acclimation strategies of this small phytoplankton in a changing environment. Genomic inference reveals potential climate change-driven range expansion of the phytoplankton species Pelagomonas calceolata.}, keywords = {Biogeography, comparative genomics, metagenomics, RCC100, Water microbiology}, issn = {2399-3642}, doi = {10.1038/s42003-022-03939-z}, url = {https://www.nature.com/articles/s42003-022-03939-z}, author = {Gu{\'e}rin, Nina and Ciccarella, Marta and Flamant, Elisa and Fr{\'e}mont, Paul and Mangenot, Sophie and Istace, Benjamin and Noel, Benjamin and Belser, Caroline and Bertrand, Laurie and Labadie, Karine and Cruaud, Corinne and Romac, Sarah and Bachy, Charles and Gachenot, Martin and Pelletier, Eric and Alberti, Adriana and Jaillon, Olivier and Wincker, Patrick and Aury, Jean-Marc and Carradec, Quentin} } @article {penot_genomic_2022, title = {Genomic and meta-genomic insights into the functions, diversity and global distribution of haptophyte algae}, journal = {Applied Phycology}, year = {2022}, note = {Publisher: Taylor \& Francis _eprint: https://doi.org/10.1080/26388081.2022.2103732}, pages = {1{\textendash}20}, abstract = {Haptophytes are an environmentally important phylum of eukaryotic phytoplankton, forming the second most abundant algal group after diatoms in recent estimates of ocean biodiversity. Haptophytes are phylogenetically and functionally diverse, including globally distributed and bloom-forming calcifying species such as Emiliania and Coccolithus, and non-calcifying orders that may form important components of phytoplankton communities in polar (Phaeocystis, Chrysochromulina) through to sub-tropical latitudes (Pavlova). In this review, we synthesize available phylogenetic, genomic and environmental information concerning the diversity of haptophyte life, considering the origins and placement on the eukaryotic tree; the diversity of the five major orders (Pavlovophyceae, Phaeocystales, Prymnesiales, the CSZ clade, and Isochrysidales); and the contrasting biogeographical distributions of haptophyte groups across different Tara Oceans sampling stations and size fractions. We additionally consider outstanding questions within the fields of haptophyte diversity and biology, particularly in the context of newly discovered and largely uncultured major groups (DPL lineages and Rappemonads), and current gaps in our knowledge of genomic content and niche adaptation across the haptophyte tree.}, keywords = {18S rDNA, coccolithophorid, dispersal, meta-genomics, niche adaptation, prymnesiophyte, RCC1129, RCC1187, RCC1387, RCC1480, RCC1532, RCC851, RCC914, systematics, to read}, issn = {null}, doi = {10.1080/26388081.2022.2103732}, url = {https://doi.org/10.1080/26388081.2022.2103732}, author = {Penot, Mathias and Dacks, Joel B. and Read, Betsy and Dorrell, Richard G.} } @article {dore_global_2022, title = {Global Phylogeography of Marine Synechococcus in Coastal Areas Reveals Strong Community Shifts}, journal = {mSystems}, year = {2022}, note = {Publisher: American Society for Microbiology}, pages = {e00656{\textendash}22}, abstract = {Marine Synechococcus comprise a numerically and ecologically prominent phytoplankton group, playing a major role in both carbon cycling and trophic networks in all oceanic regions except in the polar oceans. Despite their high abundance in coastal areas, our knowledge of Synechococcus communities in these environments is based on only a few local studies. Here, we use the global metagenome data set of the Ocean Sampling Day (June 21st, 2014) to get a snapshot of the taxonomic composition of coastal Synechococcus communities worldwide, by recruitment on a reference database of 141 picocyanobacterial genomes, representative of the whole Prochlorococcus, Synechococcus, and Cyanobium diversity. This allowed us to unravel drastic community shifts over small to medium scale gradients of environmental factors, in particular along European coasts. The combined analysis of the phylogeography of natural populations and the thermophysiological characterization of eight strains, representative of the four major Synechococcus lineages (clades I to IV), also brought novel insights about the differential niche partitioning of clades I and IV, which most often co-dominate the Synechococcus community in cold and temperate coastal areas. Altogether, this study reveals several important characteristics and specificities of the coastal communities of Synechococcus worldwide. IMPORTANCE Synechococcus is the second most abundant phytoplanktonic organism on Earth, and its wide genetic diversity allowed it to colonize all the oceans except for polar waters, with different clades colonizing distinct oceanic niches. In recent years, the use of global metagenomics data sets has greatly improved our knowledge of {\textquotedblleft}who is where{\textquotedblright} by describing the distribution of Synechococcus clades or ecotypes in the open ocean. However, little is known about the global distribution of Synechococcus ecotypes in coastal areas, where Synechococcus is often the dominant phytoplanktonic organism. Here, we leverage the global Ocean Sampling Day metagenomics data set to describe Synechococcus community composition in coastal areas worldwide, revealing striking community shifts, in particular along the coasts of Europe. As temperature appears as an important driver of the community composition, we also characterize the thermal preferenda of 8 Synechococcus strains, bringing new insights into the adaptation to temperature of the dominant Synechococcus clades.}, keywords = {RCC1086, RCC1695, RCC2369, rcc2380, RCC2553, RCC2556, RCC2570, rcc791}, doi = {10.1128/msystems.00656-22}, url = {https://journals.asm.org/doi/full/10.1128/msystems.00656-22}, author = {Dor{\'e}, Hugo and Leconte, Jade and Guyet, Ulysse and Breton, Sol{\`e}ne and Farrant, Gregory K. and Demory, David and Ratin, Morgane and Hoebeke, Mark and Corre, Erwan and Pitt, Frances D. and Ostrowski, Martin and Scanlan, David J. and Partensky, Fr{\'e}d{\'e}ric and Six, Christophe and Garczarek, Laurence} } @article {liao_group_2022, title = {Group 2i Isochrysidales flourishes at exceedingly low growth temperatures (0 to 6 {\textdegree}C)}, journal = {Organic Geochemistry}, year = {2022}, pages = {104512}, keywords = {RCC5486}, issn = {01466380}, doi = {10.1016/j.orggeochem.2022.104512}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0146638022001462}, author = {Liao, Sian and Huang, Yongsong} } @article {vazquez_high-co2_2022, title = {High-CO2 Levels Rather than Acidification Restrict Emiliania huxleyi Growth and Performance}, journal = {Microbial Ecology}, year = {2022}, abstract = {The coccolithophore Emiliania huxleyi shows a variety of responses to ocean acidification (OA) and to high-CO2 concentrations, but there is still controversy on differentiating between these two factors when using different strains and culture methods. A heavily calcified type A strain isolated from the Norwegian Sea was selected and batch cultured in order to understand whether acclimation to OA was mediated mainly by CO2 or H+, and how it impacted cell growth performance, calcification, and physiological stress management. Emiliania huxleyi responded differently to each acidification method. CO2-enriched aeration (1200 {\textmu}atm, pH 7.62) induced a negative effect on the cells when compared to acidification caused by decreasing pH alone (pH 7.60). The growth rates of the coccolithophore were more negatively affected by high pCO2 than by low pH without CO2 enrichment with respect to the control (400 {\textmu}atm, pH 8.1). High CO2 also affected cell viability and promoted the accumulation of reactive oxygen species (ROS), which was not observed under low pH. This suggests a possible metabolic imbalance induced by high CO2 alone. In contrast, the affinity for carbon uptake was negatively affected by both low pH and high CO2. Photochemistry was only marginally affected by either acidification method when analysed by PAM fluorometry. The POC and PIC cellular quotas and the PIC:POC ratio shifted along the different phases of the cultures; consequently, calcification did not follow the same pattern observed in cell stress and growth performance. Specifically, acidification by HCl addition caused a higher proportion of severely deformed coccoliths, than CO2 enrichment. These results highlight the capacity of CO2 rather than acidification itself to generate metabolic stress, not reducing calcification.}, keywords = {Calcification, coccolithophores, Emiliania huxleyi, Ocean acidification, pCO2, Photochemistry, phytoplankton, rcc1226, Stress}, issn = {1432-184X}, doi = {10.1007/s00248-022-02035-3}, url = {https://doi.org/10.1007/s00248-022-02035-3}, author = {V{\'a}zquez, V{\'\i}ctor and Le{\'o}n, Pablo and Gordillo, Francisco J. L. and Jim{\'e}nez, Carlos and Concepci{\'o}n, I{\~n}iguez and Mackenzie, Kevin and Bresnan, Eileen and Segovia, Mar{\'\i}a} } @article {fernandes_high-value_2022, title = {High-value lipids accumulation by Pavlova pinguis as a response to nitrogen-induced changes}, journal = {Biomass and Bioenergy}, volume = {158}, year = {2022}, month = {mar}, pages = {106341}, abstract = {The challenges of exploring the potential of microalgal strains for biotechnological applications include the optimization of their cell growth and chemical composition. To overcome this, it is essential to understand the mechanisms that lead to the accumulation of desired products within microalgal cells. In this study, a gradient of nitrogen as nitrate (NO3{\textendash}N) concentrations was used for the preparation of P. pinguis growth medium. The algal growth dynamics, pigments, nutrient uptake, and detailed lipid composition across treatments were assessed. Increasing the NO3{\textendash}N level led to higher lipid content (21\%), a higher cell uptake rate (0.20 pg NO3{\textendash}N cell-1 d-1) and more accumulation of chlorophylls, carotenoids, and high-value lipids. Eicosapentaenoic acid, essential fatty acids, phytol and stigmasterol were the key high-value lipids that were positively influenced by higher NO3{\textendash}N levels. High NO3{\textendash}N conditions induced an increase of 54\% in total sterol content, while low NO3{\textendash}N conditions resulted in increased proportions of saturated fatty acids (66\% more) and decreased proportions of polyunsaturated fatty acids (14\% less). The low NO3{\textendash}N level also led to higher amounts of monoglyceride (1.60 mg g-1; 64\% more). The analysis of P. pinguis lipids before and after hydrolysis provided an insight into the composition of the esterified lipids across treatments. NO3{\textendash}N supplementation was revealed to be an effective strategy for enhancing P. pinguis lipid composition, for nutraceutical and pharmaceutical industries (high NO3{\textendash}N level). A greater understanding of the NO3{\textendash}N uptake and the use efficiency by P. pinguis was reached, showing its potential for further biotechnological applications.}, keywords = {Biotechnological application, High-value lipids, RCC1359, supply}, issn = {0961-9534}, doi = {10.1016/j.biombioe.2022.106341}, url = {https://www.sciencedirect.com/science/article/pii/S0961953422000022}, author = {Fernandes, Tom{\'a}sia and Cordeiro, Nereida} } @article {parsy_impact_2022, title = {Impact of salinities, metals and organic compounds found in saline oil \& gas produced water on microalgae and cyanobacteria}, journal = {Ecotoxicology and Environmental Safety}, volume = {234}, year = {2022}, pages = {113351}, abstract = {This work evaluates the impact of salinity and the toxicity of some metals and organic compounds commonly found in produced waters on the growth of model photosynthetic organisms. Five strains of marine microalgae and one cyanobacteria (i.e. Dunaliella salina, Nannochloropsis oceanica, Tetraselmis suecica, Picochlorum cos- tavermella, Coccomyxa simplex and Synechococcus rubescens) were tested in microplates as well as the freshwater Chlorella vulgaris selected as reference. Results revealed that D.salina was able to growth at high salinity (up to 135 g.L- 1). Copper was the most toxic metal for all strains (half maximal effective concentration between 0.1 and 10 mg.L- 1) except for D.salina and C.simplex. These two strains were the most resistant to all metals tested. All organic compounds presented half maximal effective concentration above 10 mg.L- 1, none of them being very toxic for the studied microorganisms. P.costavermella and C.simplex were the most resistant strains to organic compounds. Looking at tolerance to salinity, metals and organic compounds, D.salina appeared to be the best choice for biomass production in produced waters. In addition, growths in 80\% artificial produced water sup- plemented with f medium confirm the feasibility to use this medium to produce biomass.}, keywords = {RCC4223, RCC537, rcc752}, issn = {01476513}, doi = {10.1016/j.ecoenv.2022.113351}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0147651322001919}, author = {Parsy, Aur{\'e}lien and Guyoneaud, R{\'e}my and Lot, Marie-Claire and Baldoni-Andrey, Patrick and P{\'e}ri{\'e}, Fr{\'e}d{\'e}ric and Sambusiti, Cecilia} } @article {zhang_intense_2022, title = {Intense blooms of Phaeocystis globosa in the South China Sea are caused by a unique {\textquotedblleft}giant-colony{\textquotedblright} ecotype}, journal = {Harmful Algae}, volume = {114}, year = {2022}, pages = {102227}, abstract = {The haptophyte Phaeocystis globosa, an important causative agent of harmful algal blooms globally, exhibits varying morphological and physiological features and high genetic diversity, yet the relationship among these has never been elucidated. In this study, colony sizes and pigment profiles of 19 P. globosa isolates from the Pacific and Atlantic Oceans were determined. Genetic divergence of these strains was analyzed using the chloroplast rbcS-rpl27 intergenic spacer, a novel high-resolution molecular marker. Strains could be divided into four genetic clades based on these sequences, or two groups based on colony size and the identity of diagnostic pigments (19{\textquoteright}-hexanoyloxyfucoxanthin, hex-fuco, and 19{\textquoteright}-butanoyloxyfucoxanthin, but-fuco). Three strains from the South China Sea (SCS), all belonging to the same genetic clade, have unique biological features in forming giant colonies and possessing but-fuco as their diagnostic pigment. Based on these findings, we propose that these SCS strains should be a unique {\textquotedblleft}giant-colony{\textquotedblright} ecotype of P. globosa. During the period 2016-2021, more than 1000 rbcS-rpl27 sequences were obtained from 16 P. globosa colony samples and 18 phytoplankton samples containing solitary P. globosa cells in the SCS. Phylogenetic analysis indicated that >95\% of the sequences from P. globosa colonies in the SCS were comprised of the {\textquotedblleft}giant-colony{\textquotedblright} ecotype, whereas the genetic diversity of solitary cells was much higher. Results demonstrated that intense blooms of P. globosa featuring giant colonies in the SCS were mainly caused by this giant-colony P. globosa ecotype.}, keywords = {ecotype, genetic diversity, Giant colony, Marker pigment, RCC1736, RCC2055, RCC678, RCC736}, issn = {1568-9883}, doi = {10.1016/j.hal.2022.102227}, url = {https://www.sciencedirect.com/science/article/pii/S1568988322000555}, author = {Zhang, Qing-Chun and Liu, Chao and Wang, Jin-Xiu and Kong, Fan-Zhou and Niu, Zhuang and Xiang, Ling and Yu, Ren-Cheng} } @article {biller_isolation_2022, title = {Isolation and Characterization of Cyanobacterial Extracellular Vesicles}, journal = {Journal of Visualized Experiments}, year = {2022}, month = {feb}, abstract = {Cyanobacteria are a diverse group of photosynthetic, Gram-negative bacteria that play critical roles in global ecosystems and serve as essential biotechnology models. Recent work has demonstrated that both marine and freshwater cyanobacteria produce extracellular vesicles - small membrane-bound structures released from the outer surface of the microbes. While vesicles likely contribute to diverse biological processes, their specific functional roles in cyanobacterial biology remain largely unknown. To encourage and advance research in this area, a detailed protocol is presented for isolating, concentrating, and purifying cyanobacterial extracellular vesicles. The current work discusses methodologies that have successfully isolated vesicles from large cultures of Prochlorococcus, Synechococcus, and Synechocystis. Methods for quantifying and characterizing vesicle samples from these strains are presented. Approaches for isolating vesicles from aquatic field samples are also described. Finally, typical challenges encountered with cyanobacterial vesicle purification, methodological considerations for different downstream applications, and the trade-offs between approaches are also discussed.}, doi = {10.3791/63481}, author = {Biller, Steven and Mu{\~n}oz Marin, Maria and Lima, Steeve and Matinha-Cardoso, Jorge and Tamagnini, Paula and Oliveira, Paulo} } @article {falciatore_light-driven_2022, title = {Light-driven processes: key players of the functional biodiversity in microalgae}, journal = {Comptes Rendus. Biologies}, volume = {345}, number = {2}, year = {2022}, pages = {1{\textendash}24}, doi = {10.5802/crbiol.80}, url = {https://comptes-rendus.academie-sciences.fr/biologies/articles/10.5802/crbiol.80/}, author = {Falciatore, Angela and Bailleul, Benjamin and Boulouis, Alix and Bouly, Jean-Pierre and Bujaldon, Sandrine and Cheminant-Navarro, Soizic and Choquet, Yves and Vitry, Catherine de and Eberhard, Stephan and Jaubert, Marianne and Kuras, Richard and Lafontaine, Ingrid and Landier, Sophie and Selles, Julien and Vallon, Olivier and Wostrikoff, Katia} } @article {castejon_limpet_2022, title = {Limpet larvae (Patella aspera R{\"o}ding, 1798), obtained by gonad dissection and fecundation in vitro, settled and metamorphosed on crustose coralline algae}, journal = {Journal of the Marine Biological Association of the United Kingdom}, year = {2022}, note = {Publisher: Cambridge University Press}, month = {feb}, pages = {1{\textendash}12}, abstract = {

The limpet Patella aspera R{\"o}ding, 1798, is a native species from the Macaronesian region whose fishing is regulated. The early life of limpets, including the settlement process, is poorly known thus far. The current study evaluated different substrates to induce settlement in P. aspera, including microalgae strains (Halamphora coffeaeformis, Navicula incerta and Pavlova sp.) and crustose coralline algae (CCA) obtained from limpet shells. The results showed that gametes obtained by dissection and matured artificially using alkalinized seawater baths can produce viable larvae able to metamorphose to juveniles. Feeding was not required during larval development, suggesting lecithotrophy. Early postlarvae were identified by the shedding of the velum, and juveniles were identified by teleoconch and active grazing behaviour. The presence of CCA shortened the timing for settlement and increased the ratio of juveniles. The type and abundance of CCA can influence settlement success. Moreover, the results suggested that settlement and metamorphosis in true limpets (Patellogastropoda) might be triggered by a two-step mechanism, i.e. a first cue influencing the shift between swimming and crawling activity and a second cue determining settlement and metamorphosis to early postlarvae and juveniles.

}, keywords = {Early postlarvae, lecithotrophy, metamorphosis, oocyte alkalinization, pediveliger larvae, RCC3458, settlement}, issn = {0025-3154, 1469-7769}, doi = {10.1017/S0025315421000916}, author = {Castej{\'o}n, Diego and Nogueira, Natacha and Andrade, Carlos A. P.} } @article {dominguez-martin_marine_2022, title = {Marine \textit{Synechococcus sp. Strain WH7803 Shows Specific Adaptative Responses to Assimilate Nanomolar Concentrations of Nitrate}, journal = {Microbiology Spectrum}, volume = {10}, number = {4}, year = {2022}, month = {aug}, pages = {e00187{\textendash}22}, abstract = {Marine Synechococcus, together with Prochlorococcus, contribute to a significant proportion of the primary production on Earth. The spatial distribution of these two groups of marine picocyanobacteria depends on different factors such as nutrient availability and temperature. Some Synechococcus ecotypes thrive in mesotrophic and moderately oligotrophic waters, where they exploit both oxidized and reduced forms of nitrogen. Here, we present a comprehensive study, which includes transcriptomic and proteomic analyses of the response of Synechococcus sp. strain WH7803 to nanomolar concentrations of nitrate, compared to micromolar ammonium or nitrogen starvation. We found that Synechococcus has a specific response to a nanomolar nitrate concentration that differs from the response shown under nitrogen starvation or the presence of standard concentrations of either ammonium or nitrate. This fact suggests that the particular response to the uptake of nanomolar concentrations of nitrate could be an evolutionary advantage for marine Synechococcus against Prochlorococcus in the natural environment.}, keywords = {rcc752}, issn = {2165-0497}, doi = {10.1128/spectrum.00187-22}, url = {https://journals.asm.org/doi/10.1128/spectrum.00187-22}, author = {Dom{\'\i}nguez-Mart{\'\i}n, Maria Agustina and L{\'o}pez-Lozano, Antonio and Melero-Rubio, Yesica and G{\'o}mez-Baena, Guadalupe and Jim{\'e}nez-Estrada, Juan Andr{\'e}s and Kukil, Kateryna and D{\'\i}ez, Jes{\'u}s and Garc{\'\i}a-Fern{\'a}ndez, Jos{\'e} Manuel}, editor = {Hom, Erik F. Y.} } @article {nikitashina_metabolic_2022, title = {Metabolic adaptation of diatoms to hypersalinity}, journal = {Phytochemistry}, year = {2022}, pages = {113267}, abstract = {Microalgae are important primary producers and form the basis for the marine food web. As global climate changes, so do salinity levels that algae are exposed to. A metabolic response of algal cells partly alleviates the resulting osmotic stress. Some metabolites involved in the response are well studied, but the full metabolic implications of adaptation remain unclear. Improved analytical methodology provides an opportunity for additional insight. We can now follow responses to stress in major parts of the metabolome and derive comprehensive charts of the resulting metabolic re-wiring. In this study, we subjected three species of diatoms to high salinity conditions and compared their metabolome to controls in an untargeted manner. The three well-investigated species with sequenced genomes Phaeodactylum tricornutum, Thalassiosira pseudonana, and Skeletonema marinoi were selected for our survey. The microalgae react to salinity stress with common adaptations in the metabolome by amino acid up-regulation, production of saccharides, and inositols. But also species-specific dysregulation of metabolites is common. Several metabolites previously not connected with osmotic stress reactions are identified, including 4-hydroxyproline, pipecolinic acid, myo-inositol, threonic acid, and acylcarnitines. This expands our knowledge about osmoadaptation and calls for further functional characterization of metabolites and pathways in algal stress physiology.}, keywords = {Diatomic algae, Hypersalinity stress response, Osmolytes, Phaeodactylaceae, Phaeodactylum tricornutum, RCC75, Skeletonema marinoi, Skeletonemataceae, Thalassiosira pseudonana, Thalassiosiraceae, Untargeted metabolite profiling}, issn = {0031-9422}, doi = {10.1016/j.phytochem.2022.113267}, url = {https://www.sciencedirect.com/science/article/pii/S0031942222001832}, author = {Nikitashina, Vera and Stettin, Daniel and Pohnert, Georg} } @article {koppelle_mixotrophy_2022, title = {Mixotrophy in the bloom-forming genus Phaeocystis and other haptophytes}, journal = {Harmful Algae}, volume = {117}, year = {2022}, pages = {102292}, abstract = {Phaeocystis is a globally widespread marine phytoplankton genus, best known for its colony-forming species that can form large blooms and odorous foam during bloom decline. In the North Sea, Phaeocystis globosa typically becomes abundant towards the end of the spring bloom, when nutrients are depleted and the share of mixo- trophic protists increases. Although mixotrophy is widespread across the eukaryotic tree of life and is also found amongst haptophytes, a mixotrophic nutrition has not yet been demonstrated in Phaeocystis. Here, we sampled two consecutive Phaeocystis globosa spring blooms in the coastal North Sea. In both years, bacterial cells were observed inside 0.6 {\textendash} 2\% of P. globosa cells using double CARD-FISH hybridizations in combination with laser scanning confocal microscopy. Incubation experiments manipulating light and nutrient availability showed a trend towards higher occurrence of intracellular bacteria under P-deplete conditions. Based on counts of bacteria inside P. globosa cells in combination with theoretical values of prey digestion times, maximum ingestion rates of up to 0.08 bacteria cell- 1 h- 1 were estimated. In addition, a gene-based predictive model was applied to the transcriptome assemblies of seven Phaeocystis strains and 24 other haptophytes to assess their trophic mode. This model predicted a phago-mixotrophic feeding strategy in several (but not all) strains of P. globosa, P. antarctica and other haptophytes that were previously assumed to be autotrophic. The observation of bacterial cells inside P. globosa and the gene-based model predictions strongly suggest that the phago-mixotrophic feeding strategy is widespread among members of the Phaeocystis genus and other haptophytes, and might contribute to their remarkable success to form nuisance blooms under nutrient-limiting conditions.}, keywords = {RCC1130, RCC1303, rcc1383, RCC1455, RCC1486, RCC1523, RCC1537, RCC918}, issn = {15689883}, doi = {10.1016/j.hal.2022.102292}, url = {https://linkinghub.elsevier.com/retrieve/pii/S1568988322001202}, author = {Koppelle, Sebastiaan and L{\'o}pez-Escard{\'o}, David and Brussaard, Corina P.D. and Huisman, Jef and Philippart, Catharina J.M. and Massana, Ramon and Wilken, Susanne} } @article {gomez_molecular_2022, title = {Molecular phylogeny of the spiny-surfaced species of the dinoflagellate Prorocentrum with the description of P. Thermophilum sp. nov. and P. criophilum sp. nov. (Prorocentrales, Dinophyceae)}, journal = {Journal of Phycology}, volume = {n/a}, number = {n/a}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/jpy.13298}, abstract = {Spiny-surfaced species of Prorocentrum forms harmful algal blooms, and its taxonomic identity is obscure due to the size and shape variability. Molecular phylogenies reveal two major clades: one for P. cordatum with sequences mainly retrieved as P. minimum, and other for P. shikokuense with sequences also retrieved as P. dentatum and P. donghaiense. Several closely related clades still need to be characterized. Here, we provide SSU- and LSU rRNA, and ITS gene sequences of the strain CCMP3122 isolated from Florida (initially named P. donghaiense) and strains Prorocentrum sp. RCC6871{\textendash}2 from the Ross Sea, Antarctica. We describe Prorocentrum thermophilum sp. nov. based on the strain CCMP3122, a species also distributed in the open waters of Gulf of Mexico, New Zealand and the Arabian Gulf; and Prorocentrum criophilum sp. nov. based on the strain RCC6872, which is distributed in the Antarctic Ocean and the Arctic Sea. Prorocentrum thermophilum is roundish ( 14 μm long, 12 μm wide), with an inconspicuous anterior spine-like prolongation under light microscopy, valves with tiny, short knobs (5{\textendash}7 per μm2), and several (<7) large trichocyst pores ( 0.3 μm) in the right valve, as well as smaller pores ( 0.15 μm). Prorocentrum criophilum is round in valve view ( 11 μm long, 10 μm wide) and asymmetrically roundish in lateral view, the periflagellar area was not discernible under light microscopy, valves with very tiny, short knobs (6{\textendash}10 per μm2), and at least twelve large pores in the right valve. Other potentially undescribed species of spiny-surfaced Prorocentrum are discussed}, keywords = {Dinophyta, HABs, harmful algae blooms, molecular phylogenetics, new species, Prorocentraceae, RCC6871, RCC6872, taxonomy}, issn = {1529-8817}, doi = {10.1111/jpy.13298}, url = {http://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.13298}, author = {G{\'o}mez, Fernando and Gourvil, Priscillia and Li, Tangcheng and Huang, Yulin and Zhang, Huan and Courcot, Lucie and Artigas, Luis F. and Soler On{\'\i}s, Emilio and Gutierrez-Rodriguez, Andres and Lin, Senjie} } @article {haney_multiple_2022, title = {Multiple Photolyases Protect the Marine Cyanobacterium Synechococcus from Ultraviolet Radiation}, journal = {mBio}, volume = {13}, number = {4}, year = {2022}, month = {aug}, pages = {e01511{\textendash}22}, abstract = {

Marine cyanobacteria depend on light for photosynthesis, restricting their growth to the photic zone. The upper part of this layer is exposed to strong UV radiation (UVR), a DNA mutagen that can harm these microorganisms. To thrive in UVR-rich waters, marine cyanobacteria employ photoprotection strategies that are still not well defined. Among these are photolyases, light-activated enzymes that repair DNA dimers generated by UVR. Our analysis of genomes of 81 strains of Synechococcus, Cyanobium, and Prochlorococcus isolated from the world{\textquoteright}s oceans shows that they possess up to five genes encoding different members of the photolyase/cryptochrome family, including a photolyase with a novel domain arrangement encoded by either one or two separate genes. We disrupted the putative photolyase-encoding genes in Synechococcus sp. strain RS9916 and discovered that each gene contributes to the overall capacity of this organism to survive UVR. Additionally, each conferred increased survival after UVR exposure when transformed into Escherichia coli lacking its photolyase and SOS response. Our results provide the first evidence that this large set of photolyases endows Synechococcus with UVR resistance that is far superior to that of E. coli, but that, unlike for E. coli, these photolyases provide Synechococcus with the vast majority of its UVR tolerance.

}, keywords = {rcc555}, issn = {2150-7511}, doi = {10.1128/mbio.01511-22}, url = {https://journals.asm.org/doi/10.1128/mbio.01511-22}, author = {Haney, Allissa M. and Sanfilippo, Joseph E. and Garczarek, Laurence and Partensky, Fr{\'e}d{\'e}ric and Kehoe, David M.}, editor = {Ruby, Edward} } @article {johnson_nutritional_2022, title = {Nutritional response of a coccolithophore to changing pH and temperature}, journal = {Limnology and Oceanography}, volume = {n/a}, number = {n/a}, year = {2022}, note = {_eprint: https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.12204}, abstract = {Coccolithophores are a calcifying unicellular phytoplankton group that are at the base of the marine food web, and their lipid content provides a source of energy to consumers. Coccolithophores are vulnerable to ocean acidification and warming, therefore it is critical to establish the effects of climate change on these significant marine primary producers, and determine potential consequences that these changes can have on their consumers. Here, we quantified the impact of changes in pH and temperature on the nutritional condition (lipid content, particulate organic carbon/nitrogen), growth rate, and morphology of the most abundant living coccolithophore species, Emiliania huxleyi. We used a regression type approach with nine pH levels (ranging from 7.66 to 8.44) and two temperatures (15{\textdegree}C and 20{\textdegree}C). Lipid production was greater under reduced pH, and growth rates were distinctly lower at 15{\textdegree}C than at 20{\textdegree}C. The production potential of lipids, which estimates the availability of lipids to consumers, increased under 20{\textdegree}C, but decreased under low pH. The results indicate that, while consumers will benefit energetically under ocean warming, this benefit will be mitigated by ocean acidification. The carbon to nitrogen ratio was higher at 20{\textdegree}C and low pH, indicating that the nutritional quality of coccolithophores for consumers will decline under climate change. The impact of low pH on the structural integrity of the coccosphere may also mean that coccolithophores are easier to digest for consumers. Many responses suggest cellular stress, indicating that increases in temperature and reductions in pH may have a negative impact on the ecophysiology of coccolithophores.}, keywords = {RCC1832}, issn = {1939-5590}, doi = {10.1002/lno.12204}, url = {http://onlinelibrary.wiley.com/doi/abs/10.1002/lno.12204}, author = {Johnson, Roberta and Langer, Gerald and Rossi, Sergio and Probert, Ian and Mammone, Marta and Ziveri, Patrizia} } @article {azizah_orchestrated_2022, title = {Orchestrated Response of Intracellular Zwitterionic Metabolites in Stress Adaptation of the Halophilic Heterotrophic Bacterium Pelagibaca bermudensis}, journal = {Marine Drugs}, volume = {20}, number = {11}, year = {2022}, month = {nov}, pages = {727}, abstract = {Osmolytes are naturally occurring organic compounds that protect cells against various forms of stress. Highly polar, zwitterionic osmolytes are often used by marine algae and bacteria to counteract salinity or temperature stress. We investigated the effect of several stress conditions including different salinities, temperatures, and exposure to organic metabolites released by the alga Tetraselmis striata on the halophilic heterotrophic bacterium Pelagibaca bermudensis. Using ultrahigh-performance liquid chromatography (UHPLC) on a ZIC-HILIC column and high-resolution electrospray ionization mass spectrometry, we simultaneously detected and quantified the eleven highly polar compounds dimethylsulfoxonium propionate (DMSOP), dimethylsulfoniopropionate (DMSP), gonyol, cysteinolic acid, ectoine, glycine betaine (GBT), carnitine, sarcosine, choline, proline, and 4-hydroxyproline. All compounds are newly described in P. bermudensis and potentially involved in physiological functions essential for bacterial survival under variable environmental conditions. We report that adaptation to various forms of stress is accomplished by adjusting the pattern and amount of the zwitterionic metabolites.}, keywords = {RCC131}, issn = {1660-3397}, doi = {10.3390/md20110727}, url = {https://www.mdpi.com/1660-3397/20/11/727}, author = {Azizah, Muhaiminatul and Pohnert, Georg} } @article {lacour_photoacclimation_2022, title = {Photoacclimation of the polar diatom Chaetoceros neogracilis at low temperature}, journal = {PLOS ONE}, volume = {17}, number = {9}, year = {2022}, note = {Publisher: Public Library of Science}, month = {sep}, pages = {e0272822}, abstract = {Polar microalgae face two major challenges: 1- growing at temperatures (-1.7 to 5{\textdegree}C) that limit enzyme kinetics; and 2- surviving and exploiting a wide range of irradiance. The objective of this study is to understand the adaptation of an Arctic diatom to its environment by studying its ability to acclimate to changes in light and temperature. We acclimated the polar diatom Chaetoceros neogracilis to various light levels at two different temperatures and studied its growth and photosynthetic properties using semi-continuous cultures. Rubisco content was high, to compensate for low catalytic rates, but did not change detectably with growth temperature. Contrary to what is observed in temperate species, in C. neogracilis, carbon fixation rate (20 min 14C incorporation) equaled net growth rate (μ) suggesting very low or very rapid (<20 min) re-oxidation of the newly fixed carbon. The comparison of saturation irradiances for electron transport, oxygen net production and carbon fixation revealed alternative electron pathways that could provide energy and reducing power to the cell without consuming organic carbon which is a very limiting product at low temperatures. High protein contents, low re-oxidation of newly fixed carbon and the use of electron pathways alternative to carbon fixation may be important characteristics allowing efficient growth under those extreme environmental conditions.}, keywords = {5-bisphosphate carboxylase oxygenase, Carbon fixation, diatoms, Fluorescence, Light, Photons, Photosynthesis, pigments, RCC2278, Ribulose-1}, issn = {1932-6203}, doi = {10.1371/journal.pone.0272822}, url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0272822}, author = {Lacour, Thomas and Larivi{\`e}re, Jade and Ferland, Joannie and Morin, Philippe-Isra{\"e}l and Grondin, Pierre-Luc and Donaher, Natalie and Cockshutt, Amanda and Campbell, Douglas A. and Babin, Marcel} } @article {carrigee_phycoerythrobilin_2022, title = {The phycoerythrobilin isomerization activity of MpeV in Synechococcus sp. WH8020 is prevented by the presence of a histidine at position 141 within its phycoerythrin-I β-subunit substrate}, journal = {Frontiers in Microbiology}, volume = {13}, year = {2022}, pages = {1011189}, abstract = {Marine Synechococcus efficiently harvest available light for photosynthesis using complex antenna systems, called phycobilisomes, composed of an allophycocyanin core surrounded by rods, which in the open ocean are always constituted of phycocyanin and two phycoerythrin (PE) types: PEI and PEII. These cyanobacteria display a wide pigment diversity primarily resulting from differences in the ratio of the two chromophores bound to PEs, the green-light absorbing phycoerythrobilin and the blue-light absorbing phycourobilin. Prior to phycobiliprotein assembly, bilin lyases post-translationally catalyze the ligation of phycoerythrobilin to conserved cysteine residues on α- or β-subunits, whereas the closely related lyase-isomerases isomerize phycoerythrobilin to phycourobilin during the attachment reaction. MpeV was recently shown in Synechococcus sp. RS9916 to be a lyase-isomerase which doubly links phycourobilin to two cysteine residues (C50 and C61; hereafter C50, 61) on the β-subunit of both PEI and PEII. Here we show that Synechococcus sp. WH8020, which belongs to the same pigment type as RS9916, contains MpeV that demonstrates lyase-isomerase activity on the PEII β-subunit but only lyase activity on the PEI β-subunit. We also demonstrate that occurrence of a histidine at position 141 of the PEI β-subunit from WH8020, instead of a leucine in its counterpart from RS9916, prevents the isomerization activity by WH8020 MpeV, showing for the first time that both the substrate and the enzyme play a role in the isomerization reaction. We propose a structural-based mechanism for the role of H141 in blocking isomerization. More generally, the knowledge of the amino acid present at position 141 of the β-subunits may be used to predict which phycobilin is bound at C50, 61 of both PEI and PEII from marine Synechococcus strains.}, keywords = {RCC2437, RCC307, RCC751}, issn = {1664-302X}, doi = {10.3389/fmicb.2022.1011189}, url = {https://www.frontiersin.org/articles/10.3389/fmicb.2022.1011189/full}, author = {Carrigee, Lyndsay A. and Frick, Jacob P. and Liu, Xindi and Karty, Jonathan A. and Trinidad, Jonathan C. and Tom, Irin P. and Yang, Xiaojing and Dufour, Louison and Partensky, Fr{\'e}d{\'e}ric and Schluchter, Wendy M.} } @article {liu_phycosphere_2022, title = {Phycosphere pH of unicellular nano- and micro- phytoplankton cells and consequences for iron speciation}, journal = {The ISME Journal}, volume = {16}, number = {10}, year = {2022}, note = {Number: 10 Publisher: Nature Publishing Group}, month = {oct}, pages = {2329{\textendash}2336}, abstract = {Surface ocean pH is declining due to anthropogenic atmospheric CO2 uptake with a global decline of \textasciitilde0.3 possible by 2100. Extracellular pH influences a range of biological processes, including nutrient uptake, calcification and silicification. However, there are poor constraints on how pH levels in the extracellular microenvironment surrounding phytoplankton cells (the phycosphere) differ from bulk seawater. This adds uncertainty to biological impacts of environmental change. Furthermore, previous modelling work suggests that phycosphere pH of small cells is close to bulk seawater, and this has not been experimentally verified. Here we observe under 140 μmol photons{\textperiodcentered}m-2{\textperiodcentered}s-1 the phycosphere pH of Chlamydomonas concordia (5 {\textmu}m diameter), Emiliania huxleyi (5 {\textmu}m), Coscinodiscus radiatus (50 {\textmu}m) and C. wailesii (100 {\textmu}m) are 0.11 {\textpm} 0.07, 0.20 {\textpm} 0.09, 0.41 {\textpm} 0.04 and 0.15 {\textpm} 0.20 (mean {\textpm} SD) higher than bulk seawater (pH 8.00), respectively. Thickness of the pH boundary layer of C. wailesii increases from 18 {\textpm} 4 to 122 {\textpm} 17 {\textmu}m when bulk seawater pH decreases from 8.00 to 7.78. Phycosphere pH is regulated by photosynthesis and extracellular enzymatic transformation of bicarbonate, as well as being influenced by light intensity and seawater pH and buffering capacity. The pH change alters Fe speciation in the phycosphere, and hence Fe availability to phytoplankton is likely better predicted by the phycosphere, rather than bulk seawater. Overall, the precise quantification of chemical conditions in the phycosphere is crucial for assessing the sensitivity of marine phytoplankton to ongoing ocean acidification and Fe limitation in surface oceans.}, keywords = {Biogeochemistry, Microbial biooceanography, RCC1, rcc1731, Water microbiology}, issn = {1751-7370}, doi = {10.1038/s41396-022-01280-1}, url = {https://www.nature.com/articles/s41396-022-01280-1}, author = {Liu, Fengjie and Gledhill, Martha and Tan, Qiao-Guo and Zhu, Kechen and Zhang, Qiong and Sala{\"u}n, Pascal and Tagliabue, Alessandro and Zhang, Yanjun and Weiss, Dominik and Achterberg, Eric P. and Korchev, Yuri} } @article {meyer_pronounced_2022, title = {Pronounced Uptake and Metabolism of Organic Substrates by Diatoms Revealed by Pulse-Labeling Metabolomics}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, pages = {821167}, abstract = {Diatoms contribute as a dominant group of microalgae to approximately 20\% of the global carbon fixation. In the plankton, these photosynthetic algae are exposed to a plethora of metabolites, especially when competing algae are lysed. It is well established that diatoms can take up specific metabolites, such as vitamins, amino acids as nitrogen source, or dimethylsulfoniopropoionate to compensate for changes in water salinity. It is, however, unclear to which extent diatoms take up other organic resources and if these are incorporated into the cell{\textasciiacute}s metabolism. Here, we explore the general scope of uptake of metabolites from competitors. Using labeled metabolites released during lysis of algae grown under a 13CO2 atmosphere, we show that the cosmopolitan diatom Chaetoceros didymus takes up even dilute organic substrates from these lysates with little bias for molecular weight or polarity. This is reflected by a high degree of labeling in the metabolome of the exposed cells. The newly developed pulse label/mass spectrometry metabolomics approach reveals that polarity and molecular weight has no detectable influence on uptake. We further show that the taken-up metabolites are partly maintained without metabolic modification within the cells, but also a substantial part is subject to catabolic and anabolic transformation. One of the most dominant phytoplankton groups thus has the potential to compete with heterotrophs, suggesting that the observed osmotrophy may substantially impact organic material fluxes in the oceans. Our findings call for the refinement of our understanding of competition in the plankton.}, keywords = {RCC75}, issn = {2296-7745}, doi = {10.3389/fmars.2022.821167}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.821167/full}, author = {Meyer, Nils and Rydzyk, Aljoscha and Pohnert, Georg} } @article {akita_providing_2022, title = {Providing a phylogenetic framework for trait-based analyses in brown algae: Phylogenomic tree inferred from 32 nuclear protein-coding sequences}, journal = {Molecular Phylogenetics and Evolution}, volume = {168}, year = {2022}, month = {mar}, pages = {107408}, abstract = {In the study of the evolution of biological complexity, a reliable phylogenetic framework is needed. Many attempts have been made to resolve phylogenetic relationships between higher groups (i.e., interordinal) of brown algae (Phaeophyceae) based on molecular evidence, but most of these relationships remain unclear. Analyses based on small multi-gene data (including chloroplast, mitochondrial and nuclear sequences) have yielded inconclusive and sometimes contradictory results. To address this problem, we have analyzed 32 nuclear protein-coding sequences in 39 Phaeophycean species belonging to eight orders. The resulting nuclear-based phylogenomic trees provide virtually full support for the phylogenetic relationships within the studied taxa, with few exceptions. The relationships largely confirm phylogenetic trees based on nuclear, chloroplast and mitochondrial sequences, except for the placement of the Sphacelariales with weak bootstrap support. Our study indicates that nuclear protein-coding sequences provide significant support to conclusively resolve phylogenetic relationships among Phaeophyceae, and may be a powerful approach to fully resolve interordinal relationships with increased taxon sampling.}, keywords = {Ectocarpales, genomics, Heterokontophytes, Phaeoexplorer, Phaeophyceae, RCC4962, RCC7086, RCC7088, RCC7090, RCC7092, RCC7094, RCC7096, RCC7098, RCC7101, RCC7104, RCC7107, RCC7108, RCC7109, RCC7112, RCC7115, RCC7116, RCC7117, RCC7120, RCC7123, RCC7124, RCC7125, RCC7127, RCC7129, RCC7131, RCC7134, RCC7137, RCC7138, RCC7139, stramenopiles}, issn = {1055-7903}, doi = {10.1016/j.ympev.2022.107408}, url = {https://www.sciencedirect.com/science/article/pii/S1055790322000215}, author = {Akita, Shingo and Vieira, Christophe and Hanyuda, Takeaki and Rousseau, Florence and Cruaud, Corinne and Couloux, Arnaud and Heesch, Svenja and Cock, J. Mark and Kawai, Hiroshi} } @article {fan_quantifying_2022, title = {Quantifying the Extent of Calcification of a Coccolithophore Using a Coulter Counter}, journal = {Analytical Chemistry}, year = {2022}, month = {sep}, pages = {acs.analchem.2c01971}, abstract = {Although, in principle, the Coulter Counter technique yields an absolute measure of particle volume, in practice, calibration is nearuniversally employed. For regularly shaped and non-biological samples, the use of latex beads for calibration can provide sufficient accuracy. However, this is not the case with particles encased in biogenically formed calcite. To date, there has been no effective route by which a Coulter Counter can be calibrated to enable the calcification of coccolithophores�single cells encrusted with biogenic calcite�to be quantified. Consequently, herein, we seek to answer the following question: to what extent can a Coulter Counter be used to provide accurate information regarding the calcite content of a singlespecies coccolithophore population? Through the development of a new calibration methodology, based on the measurement and dynamic tracking of the acid-driven calcite dissolution reaction, a route by which the cellular calcite content can be determined is presented. This new method allows, for the first time, a Coulter Counter to be used to yield an absolute measurement of the amount of calcite per cell.}, keywords = {RCC1198, RCC1216, RCC1314}, issn = {0003-2700, 1520-6882}, doi = {10.1021/acs.analchem.2c01971}, url = {https://pubs.acs.org/doi/10.1021/acs.analchem.2c01971}, author = {Fan, Xinmeng and Batchelor-McAuley, Christopher and Yang, Minjun and Barton, Samuel and Rickaby, Rosalind E. M. and Bouman, Heather A. and Compton, Richard G.} } @mastersthesis {groussman_resolving_2022, title = {Resolving the molecular ecology of marine microbial eukaryotes with metatranscriptomes}, year = {2022}, school = {University of Washington}, type = {phd}, keywords = {RCC1007, ⛔ No DOI found}, url = {https://digital.lib.washington.edu/researchworks/bitstream/handle/1773/49735/Groussman_washington_0250E_25089.pdf}, author = {Groussman, Ryan D} } @article {pilatova_revisiting_2022, title = {Revisiting biocrystallization: purine crystalline inclusions are widespread in eukaryotes}, journal = {The ISME Journal}, year = {2022}, month = {jun}, keywords = {RCC1350, RCC745}, issn = {1751-7362, 1751-7370}, doi = {10.1038/s41396-022-01264-1}, url = {https://www.nature.com/articles/s41396-022-01264-1}, author = {Pil{\'a}tov{\'a}, Jana and P{\'a}nek, Tom{\'a}{\v s} and Obornik, Miroslav and {\v C}epi{\v c}ka, Ivan and Mojze{\v s}, Peter} } @article {de_la_broise_scale-up_2022, title = {Scale-Up to Pilot of a Non-Axenic Culture of Thraustochytrids Using Digestate from Methanization as Nitrogen Source}, journal = {Marine Drugs}, volume = {20}, number = {8}, year = {2022}, month = {aug}, pages = {499}, abstract = {The production of non-fish based docosahexaenoic acid (DHA) for feed and food has become a critical need in our global context of over-fishing. The industrial-scale production of DHA{\textendash}rich Thraustochytrids could be an alternative, if costs turned out to be competitive. In order to reduce production costs, this study addresses the feasibility of the non-axenic (non-sterile) cultivation of Aurantiochytrium mangrovei on industrial substrates (as nitrogen and mineral sources and glucose syrup as carbon and energy sources), and its scale-up from laboratory (250 mL) to 500 L cultures. Pilot-scale reactors were airlift cylinders. Batch and fed-batch cultures were tested. Cultures over 38 to 62 h achieved a dry cell weight productivity of 3.3 to 5.5 g.L-1.day-1, and a substrate to biomass yield of up to 0.3. DHA productivity ranged from 10 to 0.18 mg.L-1.day-1. Biomass productivity appears linearly related to oxygen transfer rate. Bacterial contamination of cultures was low enough to avoid impacts on fatty acid composition of the biomass. A specific work on microbial risks assessment (in supplementary files) showed that the biomass can be securely used as feed. However, to date, there is a law void in EU legislation regarding the recycling of nitrogen from digestate from animal waste for microalgae biomass and its usage in animal feed. Overall, the proposed process appears similar to the industrial yeast production process (non-axenic heterotrophic process, dissolved oxygen supply limiting growth, similar cell size). Such similarity could help in further industrial developments.}, keywords = {RCC893}, issn = {1660-3397}, doi = {10.3390/md20080499}, url = {https://www.mdpi.com/1660-3397/20/8/499}, author = {de la Broise, Denis and Ventura, Mariana and Chauchat, Luc and Guerreiro, Maurean and Michez, Teo and Vinet, Thibaud and Gautron, Nicolas and Le Grand, Fabienne and Bideau, Antoine and Go{\"\i}c, Nelly Le and Bidault, Adeline and Lambert, Christophe and Soudant, Philippe} } @article {croteau_shifts_2022, title = {Shifts in growth light optima among diatom species support their succession during the spring bloom in the Arctic}, journal = {Journal of Ecology}, volume = {n/a}, number = {n/a}, year = {2022}, note = {_eprint: https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2745.13874}, abstract = {1. Diatoms of the Arctic Ocean annually experience extreme changes of light environment linked to photoperiodic cycles and seasonal variations of the snow and sea-ice cover extent and thickness which attenuate light penetration in the water column. Arctic diatom communities exploit this complex seasonal dynamic through a well-documented species succession during spring, beginning in sea-ice and culminating in massive phytoplankton blooms underneath sea-ice and in the marginal ice zone. The pattern of diatom taxa sequentially dominating this succession is relatively well conserved interannually, and taxonomic shifts seem to align with habitat transitions. 2. To understand whether differential photoadaptation strategies among diatom taxa explain these recurring succession sequences, we coupled lab experiments with field work in Baffin Bay at 67.5{\textdegree}N. Based on field data, we selected five diatom species typical of different ecological niches and measured their growth rates under light intensity ranges representative of their natural habitats. To characterize their photoacclimative responses, we sampled pigments and total particulate carbon, and conducted 14C-uptake photosynthesis response curves and variable fluorescence measurements. 3. We documented a gradient in species respective light intensity for maximal growth suggesting divergent light response plasticity, which for the most part align with species sequential dominance. Other photophysiological parameters supported this ecophysiological framing, although contrasts were always clear only between succession endmembers, Nitzschia frigida and Chaetoceros neogracilis. To validate that these photoacclimative responses are representative of in situ dynamics, we compared them to the chlorophyll a-specific light-limited slope (α*) and saturated rate of photosynthesis (P*M), monitored in Baffin Bay on sea-ice and planktonic communities. This complementary approach confirmed that unusual responses in α* and P*M as a function of light history intensity are similar between sentinel sympagic species N. frigida and natural ice-core communities. While no light-history-dependent trends were observed in planktonic communities, their α* and P*M values were in the range of measurements from our monospecific cultures. 4. Synthesis. Our results suggest that Arctic diatoms species photoadaptation strategy is tuned to the light environment of the habitats in which they dominate and indeed drives the seasonal taxonomic succession.}, keywords = {Arctic Ocean, diatoms, Ecophysiology, photoacclimation, photoadaptation, primary production, RCC2046, RCC2278, seasonal species succession, spring bloom}, issn = {1365-2745}, doi = {10.1111/1365-2745.13874}, url = {http://onlinelibrary.wiley.com/doi/abs/10.1111/1365-2745.13874}, author = {Croteau, D. and Lacour, T. and Schiffrine, N. and Morin, P.-I. and Forget, M.-H. and Bruyant, F. and Ferland, J. and Lafond, A. and Campbell, D. A. and Tremblay, J.-E. and Babin, M. and Lavaud, J.} } @article {leblond_sterols_2022, title = {Sterols of Testudodinium testudo (formerly Amphidinium testudo): Production of the Δ8(14) sterol gymnodinosterol and chemotaxonomic relationship to the Kareniaceae}, journal = {Journal of Eukaryotic Microbiology}, volume = {n/a}, number = {n/a}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/jeu.12929}, pages = {e12929}, abstract = {Testudodinium testudo is a peridinin-containing dinoflagellate recently renamed from Amphidinium testudo. While T. testudo has been shown via phylogenetic analysis of small subunit ribosomal RNA genes to reside in a clade separate from the genus Amphidinium, it does possess morphological features similar to Amphidinium sensu stricto. Previous studies of Amphidinium carterae and Amphidinium corpulentum have found the sterols to be enriched in Δ8(14) sterols, such as 4α-methyl-5α-ergosta-8(14),24(28)-dien-3β-ol (amphisterol), uncommon to most other dinoflagellate taxa and thus considered possible biomarkers for the genus Amphidinium. Here, we provide an examination of the sterols of T. testudo and show they are dominated not by amphisterol, but rather by a different Δ8(14) sterol, (24R)-4α-methyl-5α-ergosta-8(14),22-dien-3β-ol (gymnodinosterol), previously thought to be a major sterol only within the Kareniaceae genera Karenia, Karlodinium, and Takayama. Also found to be present at low levels were 4α-methyl-5α-ergosta-8,14,22-trien-3β-ol, a sterol previously observed in Karenia brevis to be an intermediate in the production of gymnodinosterol, and cholesterol, a sterol common to many other dinoflagellates. The presence of gymnodinosterol in T. testudo is the first report of this sterol as the sole major sterol in a dinoflagellate outside of the Kareniaceae. The implication of this chemotaxonomic relationship to the Kareniaceae is discussed.}, keywords = {Amphidinium, Dinoflagellate, Dinophyceae, lipid, RCC1981, sterol, Testudodinium}, issn = {1550-7408}, doi = {10.1111/jeu.12929}, url = {http://onlinelibrary.wiley.com/doi/abs/10.1111/jeu.12929}, author = {Leblond, Jeffrey D. and Elkins, Lindsey C. and Sabir, Kyra and Graeff, Jori E.} } @article {arin_taxonomic_2022, title = {Taxonomic relationship between two small-sized Chaetoceros species (Bacillariophyta): C. tenuissimus and C. salsugineus , and comparison with C. olympicus sp. nov. from Catalan coastal waters (NW Mediterranean)}, journal = {European Journal of Phycology}, volume = {57}, number = {3}, year = {2022}, pages = {277{\textendash}296}, abstract = {

The majority of species of the highly diverse genus Chaetoceros are described as chain-forming, although several species are described as strictly solitary (such as C. tenuissimus) or having an alternate solitary and a chain-forming phase during their life history (such as C. salsugineus). In this study, the diversity of small forms of Chaetoceros from the NW Mediterranean coastal waters was explored through the morphological and molecular characterization of four different strains belonging to two distinct species. Based on their morphology, three of the strains were identified as C. salsugineus (Takano, 1983). The SSU and LSU rDNA sequences represented the first available for well-characterized C. salsugineus strains and were 96.6{\textendash}100\% similar to publicly available C. tenuissimus (Meunier, 1913) sequences. Both species share the same morphological features, such as setae and ultrastructure of the valves, as well as the rimoportula characteristics. In addition, the morphology of the solitary form of C. salsugineus matched with that of C. tenuissimus. Here, we propose the two species as synonyms (the name C. tenuissimus prevailing as it has priority for this taxon), emend the original description and designate an epitype. The fourth strain was identified as C. olympicus sp. nov., a new species, which alternates solitary and chain-forming forms within its life history. The main differential characteristics of this species are the absence of rimoportula both in terminal and intercalary valves, the setae ultrastructure, which is thin and circular in cross-section with a few, slightly twisted, rows of small rectangular poroids and some spirally arranged spines, and the morphology of the resting spores, with primary valve vaulted and covered with short to medium-sized spines, and secondary valve smaller, rounded and smooth. A comparison of C. tenuissimus and C. olympicus with other species as well as information on their life cycle and ecology is also provided.

}, keywords = {RCC3007, RCC3008, RCC5795}, issn = {0967-0262, 1469-4433}, doi = {10.1080/09670262.2021.1966838}, url = {https://www.tandfonline.com/doi/full/10.1080/09670262.2021.1966838}, author = {Arin, Laura and Re{\~n}{\'e}, Albert and Gallisai, Rachele and Sarno, Diana and Garc{\'e}s, Esther and Estrada, Marta} } @article {schmitt_temperature_2022, title = {Temperature Affects the Biological Control of Dinoflagellates by the Generalist Parasitoid Parvilucifera rostrata}, journal = {Microorganisms}, volume = {10}, number = {2}, year = {2022}, note = {Number: 2 Publisher: Multidisciplinary Digital Publishing Institute}, pages = {385}, abstract = {The increase in emerging harmful algal blooms in the last decades has led to an extensive concern in understanding the mechanisms behind these events. In this paper, we assessed the growth of two blooming dinoflagellates (Alexandrium minutum and Heterocapsa triquetra) and their susceptibility to infection by the generalist parasitoid Parvilucifera rostrata under a temperature gradient. The growth of the two dinoflagellates differed across a range of temperatures representative of the Penz{\'e} Estuary (13 to 22 {\textdegree}C) in early summer. A. minutum growth increased across this range and was the highest at 19 and 22 {\textdegree}C, whereas H. triquetra growth was maximal at intermediate temperatures (15{\textendash}18 {\textdegree}C). Interestingly, the effect of temperature on the parasitoid infectivity changed depending on which host dinoflagellate was infected with the dinoflagellate responses to temperature following a positive trend in A. minutum (higher infections at 20{\textendash}22 {\textdegree}C) and a unimodal trend in H. triquetra (higher infections at 18 {\textdegree}C). Low temperatures negatively affected parasitoid infections in both hosts (i.e., {\textquotedblleft}thermal refuge{\textquotedblright}). These results demonstrate how temperature shifts may not only affect bloom development in microalgal species but also their control by parasitoids.}, keywords = {dinoflagellate blooms, functional response, parasitic control, RCC2800, RCC2823, RCC2982, RCC3018, RCC4398, temperature effect}, issn = {2076-2607}, doi = {10.3390/microorganisms10020385}, url = {https://www.mdpi.com/2076-2607/10/2/385}, author = {Schmitt, Matthew and Telusma, Aaron and Bigeard, Estelle and Guillou, Laure and Alves-de-Souza, Catharina} } @article {calo_tor_2022, title = {TOR signaling in the green picoalga Ostreococcus tauri}, journal = {Plant Science}, volume = {323}, year = {2022}, month = {oct}, pages = {111390}, abstract = {Target of rapamycin (TOR) is a master regulator that controls growth and metabolism by integrating external and internal signals. Although there was a great progress in the study of TOR in plants and in the model alga Chlamydomonas, scarce data are available in other green algae. Thus, in this work we studied TOR signaling in Ostreococcus tauri, the smallest free-living eukaryote described to date. This picoalga is particularly important because it has a key site at the base of the green lineage and is part of the marine phytoplankton, contributing to global photosynthesis. We investigated OtTOR complex in silico and experimentally, by using first- and second-generation TOR inhibitors, such as rapamycin and PP242. We analyzed the effect of TOR down-regulation on cell growth and on the accumulation of carbon reserves. The results showed that O. tauri responds to TOR inhibitors more similarly to plants than to Chlamydomonas, being PP242 a valuable tool to study this pathway. Besides, Ottor expression analysis revealed that the kinase is dynamically regulated under nutritional stress. Our data indicate that TOR signaling is conserved in O. tauri and we propose this alga as a good and simple model for studying TOR kinase and its regulation.}, keywords = {Carbon reserves, Green algae, Growth, Nitrogen deprivation, RCC745, TOR inhibitors, TOR kinase}, issn = {0168-9452}, doi = {10.1016/j.plantsci.2022.111390}, url = {https://www.sciencedirect.com/science/article/pii/S016894522200214X}, author = {Cal{\'o}, Gonzalo and De Marco, Mar{\'\i}a Agustina and Salerno, Graciela Lidia and Mart{\'\i}nez-No{\"e}l, Giselle Mar{\'\i}a Astrid} } @article {das_trace_2022, title = {Trace metals exposure in three different coastal compartments show specific morphological and reproductive traits across generations in a sentinel copepod}, journal = {Science of The Total Environment}, year = {2022}, month = {nov}, pages = {160378}, abstract = {The effect of exposure from several compartments of the environment at the level of individuals were rarely investigated. This study reports the effect of contaminants from varied compartments like sediment resuspension, elutriation from resuspended sediment (extract) and seawater spiked trace metal mixtures (TM) on morphological and reproductive traits of the pelagic bioindicator copepod Eurytemora affinis. At the population level of E. affinis, lowest survival was observed in dissolved exposures (TM and extract) in the first generation (G1), showing some adaptation in the second generation (G2). An opposite trend for resuspended sediment showed higher sensitivity in survival at G2. At the individual level, prosome length and volume proved to be sensitive parameters for resuspended sediments, whereas clutch size and egg diameter were more sensitive to TM and extract. Although the generation of decontamination (G3, no exposure), showed a significant recovery at the population level (survival \% along with clutch size) of E. affinis exposed to resuspended sediment, morphological characteristics like prosome length and volume showed no such recovery (lower than control, p <0.05). To the contrary, dissolved exposure showed no significant recovery from G1 to G3 on neither survival \%, clutch size, egg diameter, prosome volume, but an increase of prosome length (p <0.05). Such tradeoffs in combatting the stress from varied sources of toxicity was observed in all exposures, from G1 to G3. The number of lipid droplets inside the body cavity of E. affinis showed a significant positive correlation with trace metal bioaccumulation (p <0.01) along with a negative correlation (p <0.05) with survival and clutch size in each treatment. This confirms the inability of copepods to utilize lipids under stressful conditions. Our study tenders certain morphological and reproductive markers that show specificity to different compartments of exposure, promising an advantage in risk assessment and fish feed studies.}, keywords = {RCC1537}, issn = {00489697}, doi = {10.1016/j.scitotenv.2022.160378}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969722074800}, author = {Das, Shagnika and Souissi, Anissa and Ouddane, Baghdad and Hwang, Jiang-Shiou and Souissi, Sami} } @article {eyal_variability_2022, title = {The variability in the structural and functional properties of coccolith base plates}, journal = {Acta Biomaterialia}, volume = {148}, year = {2022}, pages = {336{\textendash}344}, abstract = {Biomineralization processes exert varying levels of control over crystallization, ranging from poorly ordered polycrystalline arrays to intricately shaped single crystals. Coccoliths, calcified scales formed by unicellular algae, are a model for a highly controlled crystallization process. The coccolith crystals nucleate next to an organic oval structure that was termed the base plate, leading to the assumption that it is responsible for the oriented nucleation of the crystals via stereochemical interactions. In recent years, several works focusing on a well-characterized model species demonstrated a fundamental role for indirect interactions that facilitate coccolith crystallization. Here, we developed the tools to extract the base plates from five different species, giving the opportunity to systematically explore the relations between base plate and coccolith properties. We used multiple imaging techniques to evaluate the structural and chemical features of the base plates under native hydrated conditions. The results show a wide range of properties, overlaid on a common rudimentary scaffold that lacks any detectable structural or chemical motifs that can explain direct nucleation control. This work emphasizes that it is the combination between the base plate and the chemical environment inside the cell that cooperatively facilitate the exquisite control over the crystallization process. Statement of significance Biological organic scaffolds can serve as functional surfaces that guide the formation of inorganic materials. However, in many cases the specific interactions that facilitate such tight regulation are complex and not fully understood. In this work, we elucidate the architecture of such amodel biological template, an organic scale that directs the assembly of exquisite crystalline arrays of marine microalgae. By using cryo electron microscopy, we reveal the native state organization of these scales from several species. The observed similarities and differences allow us to propose that the chemical microenvironment, rather than stereochemical matching, is the pivotal regulator of the process.}, keywords = {biomineralization, Calcite, Coccoliths, Cryo electron tomography, Crystallization, RCC1130, RCC1181, RCC190, RCC3777}, issn = {1742-7061}, doi = {10.1016/j.actbio.2022.06.027}, url = {https://www.sciencedirect.com/science/article/pii/S174270612200366X}, author = {Eyal, Zohar and Krounbi, Leilah and Ben Joseph, Oz and Avrahami, Emanuel M. and Pinkas, Iddo and Peled-Zehavi, Hadas and Gal, Assaf} } @article {stewart_altitudinal_2021, title = {Altitudinal Zonation of Green Algae Biodiversity in the French Alps}, journal = {Frontiers in Plant Science}, volume = {12}, year = {2021}, pages = {1066}, abstract = {Mountain environments are marked by an altitudinal zonation of habitat types. They are home to a multitude of terrestrial green algae, who have to cope with abiotic conditions specific to high elevation, e.g., high UV irradiance, alternating desiccation, rain and snow precipitations, extreme diurnal variations in temperature and chronic scarceness of nutrients. Even though photosynthetic green algae are primary producers colonizing open areas and potential markers of climate change, their overall biodiversity in the Alps has been poorly studied so far, in particular in soil, where algae have been shown to be key components of microbial communities. Here, we investigated whether the spatial distribution of green algae followed the altitudinal zonation of the Alps, based on the assumption that algae settle in their preferred habitats under the pressure of parameters correlated with elevation. We did so by focusing on selected representative elevational gradients at distant locations in the French Alps, where soil samples were collected at different depths. Soil was considered as either a potential natural habitat or temporary reservoir of algae. We showed that algal DNA represented a relatively low proportion of the overall eukaryotic diversity as measured by a universal Eukaryote marker. We designed two novel green algae metabarcoding markers to amplify the Chlorophyta phylum and its Chlorophyceae class, respectively. Using our newly developed markers, we showed that elevation was a strong correlate of species and genus level distribution. Altitudinal zonation was thus determined for about fifty species, with proposed accessions in reference databases. In particular, Planophila laetevirens and Bracteococcus ruber related species as well as the snow alga Sanguina genus were only found in soil starting at 2,000 m above sea level. Analysis of environmental and bioclimatic factors highlighted the importance of pH and nitrogen/carbon ratios in the vertical distribution in soil. Capacity to grow heterotrophically may determine the Trebouxiophyceae over Chlorophyceae ratio. The intensity of freezing events (freezing degree days), proved also determinant in Chlorophyceae distribution. Guidelines are discussed for future, more robust and precise analyses of environmental algal DNA in mountain ecosystems and address green algae species distribution and dynamics in response to environmental changes.}, keywords = {rcc, RCC1055, RCC130, RCC1563, RCC2501, RCC2960, RCC3402, RCC443, RCC4743, RCC537, RCC581, RCC6, RCC7, RCC891}, issn = {1664-462X}, doi = {10.3389/fpls.2021.679428}, url = {https://www.frontiersin.org/article/10.3389/fpls.2021.679428}, author = {Stewart, Adeline and Rioux, Delphine and Boyer, Fr{\'e}deric and Gielly, Ludovic and Pompanon, Fran{\c c}ois and Saillard, Am{\'e}lie and Thuiller, Wilfried and Valay, Jean-Gabriel and Mar{\'e}chal, {\'E}ric and Coissac, Eric} } @article {Trefaut2020, title = {Annual phytoplankton dynamics in coastal waters from fildes bay, western antarctic peninsula}, journal = {Scientific Reports}, volume = {11}, number = {1}, year = {2021}, note = {tex.mendeley-tags: RCC2265,RCC2289,RCC4582,RCC4586,RCC5152}, month = {dec}, pages = {1368}, abstract = {Year-round reports of phytoplankton dynamics in the West Antarctic Peninsula are rare and mainly limited to microscopy and/or pigment-based studies. We analyzed the phytoplankton community from coastal waters of Fildes Bay in the West Antarctic Peninsula between January 2014 and 2015 using metabarcoding of the nuclear and plastidial 18/16S rRNA gene from both size-fractionated and flow cytometry sorted samples. Overall 14 classes of photosynthetic eukaryotes were present in our samples with the following dominating: Bacillariophyta (diatoms), Pelagophyceae and Dictyochophyceae for division Ochrophyta, Mamiellophyceae and Pyramimonadophyceae for division Chlorophyta, Haptophyta and Cryptophyta. Each metabarcoding approach yielded a different image of the phytoplankton community with for example Prymnesiophyceae more prevalent in plastidial metabarcodes and Mamiellophyceae in nuclear ones. Diatoms were dominant in the larger size fractions and during summer, while Prymnesiophyceae and Cryptophyceae were dominant in colder seasons. Pelagophyceae were particularly abundant towards the end of autumn (May). In addition of Micromonas polaris and Micromonas sp. clade B3, both previously reported in Arctic waters, we detected a new Micromonas 18S rRNA sequence signature, close to, but clearly distinct from M. polaris , which potentially represents a new clade specific of the Antarctic. These results highlight the need for complementary strategies as well as the importance of year-round monitoring for a comprehensive description of phytoplankton communities in Antarctic coastal waters.}, keywords = {RCC2265, RCC2289, RCC4582, RCC4586, RCC5152}, issn = {2045-2322}, doi = {10.1038/s41598-020-80568-8}, url = {http://biorxiv.org/content/early/2020/10/27/2020.10.27.356600.abstract http://www.nature.com/articles/s41598-020-80568-8}, author = {Trefault, Nicole and de la Iglesia, Rodrigo and Moreno-Pino, Mario and Lopes dos Santos, Adriana and G{\'e}rikas Ribeiro, Catherine and Parada-Pozo, G{\'e}nesis and Cristi, Antonia and Marie, Dominique and Vaulot, Daniel} } @article {roux_bacteria_2021, title = {Bacteria enhance the production of extracellular polymeric substances by the green dinoflagellate Lepidodinium chlorophorum}, journal = {Scientific Reports}, volume = {11}, number = {1}, year = {2021}, note = {Number: 1 Publisher: Nature Publishing Group}, pages = {1{\textendash}15}, abstract = {High biomasses of the marine dinoflagellate Lepidodinium chlorophorum cause green seawater discolorations along Southern Brittany (NE Atlantic, France). The viscosity associated to these phenomena has been related to problems in oyster cultivation. The harmful effect of L. chlorophorum might originate from the secretion of Extracellular Polymeric Substances (EPS). To understand whether the EPS are produced by L. chlorophorum or its associated bacteria, or if they are a product of their interaction, batch cultures were performed under non-axenic and pseudo-axenic conditions for three strains. Maximum dinoflagellate cell abundances were observed in pseudo-axenic cultures. The non-sinking fraction of polymers (Soluble Extracellular Polymers, SEP), mainly composed of proteins and the exopolysaccharide sulphated galactan, slightly increased in pseudo-axenic cultures. The amount of Transparent Exopolymer Particles (TEP) per cell increased under non-axenic conditions. Despite the high concentrations of Particulate Organic Carbon (POC) measured, viscosity did not vary. These results suggest that the L. chlorophorum-bacteria interaction could have a detrimental consequence on the dinoflagellate, translating in a negative effect on L. chlorophorum growth, as well as EPS overproduction by the dinoflagellate, at concentrations that should not affect seawater viscosity.}, keywords = {RCC1489}, issn = {2045-2322}, doi = {10.1038/s41598-021-84253-2}, url = {http://www.nature.com/articles/s41598-021-84253-2}, author = {Roux, Pauline and Siano, Raffaele and Collin, Karine and Bilien, Gwenael and Sinquin, Corinne and Marchand, Laetitia and Zykwinska, Agata and Delbarre-Ladrat, Christine and Schapira, Mathilde} } @article {pollara_bacterial_2021, title = {Bacterial Quorum-Sensing Signal Arrests Phytoplankton Cell Division and Impacts Virus-Induced Mortality}, journal = {mSphere}, volume = {6}, number = {3}, year = {2021}, pages = {e00009{\textendash}21, /msphere/6/3/mSph.00009{\textendash}21.atom}, abstract = {Interactions between phytoplankton and heterotrophic bacteria fundamentally shape marine ecosystems by controlling primary production, structuring marine food webs, mediating carbon export, and influencing global climate. Phytoplankton-bacterium interactions are facilitated by secreted compounds; however, linking these chemical signals, their mechanisms of action, and their resultant ecological consequences remains a fundamental challenge. The bacterial quorumsensing signal 2-heptyl-4-quinolone (HHQ) induces immediate, yet reversible, cellular stasis (no cell division or mortality) in the coccolithophore Emiliania huxleyi; however, the mechanism responsible remains unknown. Using transcriptomic and proteomic approaches in combination with diagnostic biochemical and fluorescent cell-based assays, we show that HHQ exposure leads to prolonged S-phase arrest in phytoplankton coincident with the accumulation of DNA damage and a lack of repair despite the induction of the DNA damage response (DDR). While this effect is reversible, HHQ-exposed phytoplankton were also protected from viral mortality, ascribing a new role of quorum-sensing signals in regulating multitrophic interactions. Furthermore, our data demonstrate that in situ measurements of HHQ coincide with areas of enhanced micro- and nanoplankton biomass. Our results suggest bacterial communication signals as emerging players that may be one of the contributing factors that help structure complex microbial communities throughout the ocean.}, keywords = {rcc1731}, issn = {2379-5042}, doi = {10.1128/mSphere.00009-21}, url = {https://msphere.asm.org/content/6/3/e00009-21}, author = {Pollara, Scott B. and Becker, Jamie W. and Nunn, Brook L. and Boiteau, Rene and Repeta, Daniel and Mudge, Miranda C. and Downing, Grayton and Chase, Davis and Harvey, Elizabeth L. and Whalen, Kristen E.}, editor = {McMahon, Katherine} } @article {park_bioluminescence_2021, title = {Bioluminescence capability and intensity in the dinoflagellate Alexandrium species}, journal = {ALGAE}, volume = {36}, year = {2021}, abstract = {Some species in the dinoflagellate genus Alexandrium are bioluminescent. Of the 33 formally described Alexandrium species, the bioluminescence capability of only nine species have been tested, and eight have been reported to be bioluminescent. The present study investigated the bioluminescence capability of seven Alexandrium species that had not been tested. Alexandrium mediterraneum, A. pohangense, and A. tamutum were bioluminescent, but A. andersonii, A. hiranoi, A. insuetum, and A. pseudogonyaulax were not. We also measured the bioluminescent intensity of A. affine, A. fraterculus, A. mediterraneum, A. ostenfeldii, A. pacificum, A. pohangense, A. tamarense, and A. tamutum. The mean 200-second-integrated bioluminescence intensity per cell ranged from 0.02 to 32.2 {\texttimes} 104 relative luminescence unit per cell (RLU cell-1), and the mean maximum bioluminescence intensity per cell per second (BLMax) ranged from 0.01 to 10.3 {\texttimes} 104 RLU cell-1 s-1. BLMax was significantly correlated with the maximum growth rates of Alexandrium species, except for A. tamarense. A phylogenetic tree based on large subunit ribosomal DNA (LSU rDNA), showed that the bioluminescent species A. affine, A. catenella, A. fraterculus, A. mediterraneum, A. pacificum, and A. tamarense formed a large clade. However, the toxicity or mixotrophic capability of these species was split. Thus, their bioluminescence capability in this clade was more consistent than their toxicity or mixotrophic capability. Phylogenetic trees based on LSU rDNA and the luciferase gene of Alexandrium were consistent except for A. pohangense. The results of the present study can provide a basis for understanding the interspecific diversity in bioluminescence of Alexandrium.}, keywords = {RCC4104}, doi = {10.4490/algae.2021.36.12.6}, author = {Park, Sang Ah and Jeong, Hae Jin and Ok, Jin and Kang, Heechang and You, Jihyun and Eom, Se and Yoo, Yeong and Lee, Moo Joon} } @article {phelps_carbon_2021, title = {Carbon Isotope Fractionation in Noelaerhabdaceae Algae in Culture and a Critical Evaluation of the Alkenone Paleobarometer}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {22}, number = {7}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021GC009657}, pages = {e2021GC009657}, abstract = {The carbon isotope fractionation in algal organic matter ($\varepsilon$p), including the long-chain alkenones produced by the coccolithophorid family Noelaerhabdaceae, is used to reconstruct past atmospheric CO2 levels. The conventional proxy linearly relates $\varepsilon$p to changes in cellular carbon demand relative to diffusive CO2 supply, with larger $\varepsilon$p values occurring at lower carbon demand relative to supply (i.e., abundant CO2). However, the response of Gephyrocapsa oceanica, one of the dominant alkenone producers of the last few million years, has not been studied closely. Here, we subject G. oceanica to various CO2 levels by increasing pCO2 in the culture headspace, as opposed to increasing dissolved inorganic carbon (DIC) and alkalinity concentrations at constant pH. We note no substantial change in physiology, but observe an increase in $\varepsilon$p as carbon demand relative to supply decreases, consistent with DIC manipulations. We compile existing Noelaerhabdaceae $\varepsilon$p data and show that the diffusive model poorly describes the data. A meta-analysis of individual treatments (unique combinations of lab, strain, and light conditions) shows that the slope of the $\varepsilon$p response depends on the light conditions and range of carbon demand relative to CO2 supply in the treatment, which is incompatible with the diffusive model. We model $\varepsilon$p as a multilinear function of key physiological and environmental variables and find that both photoperiod duration and light intensity are critical parameters, in addition to CO2 and cell size. While alkenone carbon isotope ratios indeed record CO2 information, irradiance and other factors are also necessary to properly describe alkenone $\varepsilon$p.}, keywords = {alkenone, carbon dioxide, carbon isotope, coccolithophore, irradiance, paleobarometry, rcc, RCC1303}, issn = {1525-2027}, doi = {10.1029/2021GC009657}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021GC009657}, author = {Phelps, Samuel R. and Hennon, Gwenn M. M. and Dyhrman, Sonya T. and Hern{\'a}ndez Lim{\'o}n, Mar{\'\i}a D. and Williamson, Olivia M. and Polissar, Pratigya J.} } @article {alacid_cellcell_2021, title = {A cell{\textendash}cell atlas approach for understanding symbiotic interactions between microbes}, journal = {Current Opinion in Microbiology}, volume = {64}, year = {2021}, pages = {47{\textendash}59}, abstract = {Natural environments are composed of a huge diversity of microorganisms interacting with each other to form complex functional networks. Our understanding of the operative nature of host{\textendash}symbiont associations is limited because propagating such associations in a laboratory is challenging. The advent of single-cell technologies applied to, for example, animal cells and apicomplexan parasites has revolutionized our understanding of development and disease. Such cell atlas approaches generate maps of cell-specific processes and variations within cellular populations. These methods can now be combined with cellular-imaging so that interaction stage versus transcriptome state can be quantized for microbe-microbe interactions. We predict that the combination of these methods applied to the study of symbioses will transform our understanding of many ecological interactions, including those sampled directly from natural environments.}, issn = {1369-5274}, doi = {10.1016/j.mib.2021.09.001}, url = {https://www.sciencedirect.com/science/article/pii/S1369527421001144}, author = {Alacid, Elisabet and Richards, Thomas A} } @booklet {thomy_combining_2021, title = {Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri}, year = {2021}, month = {feb}, publisher = {LIFE SCIENCES}, type = {preprint}, abstract = {Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration appears to be random, occurring mainly at a single locus, and thus confirming the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci, and often within the vector sequence itself. From these observations, we speculate that a non-homologous end joining-like mechanism is required during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in ecologically important marine algae.}, keywords = {RCC1115}, doi = {10.20944/preprints202102.0506.v1}, url = {https://www.preprints.org/manuscript/202102.0506/v1}, author = {Thomy, Julie and Sanchez, Fr{\'e}d{\'e}ric and Gut, Marta and Cruz, Fernando and Alioto, Tyler and Piganeau, Gwenael and Grimsley, Nigel and Yau, Sheree} } @article {thomy_combining_2021, title = {Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri}, journal = {Cells}, volume = {10}, number = {3}, year = {2021}, pages = {664}, abstract = {Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration occurred randomly at a single locus in the genome and mainly as a single copy. Thus, we confirmed the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci. Furthermore, we often observed variations in the vector sequence itself. From these observations, we speculate that a nonhomologous end-joining-like mechanism is employed during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in this ecologically important marine alga.}, keywords = {RCC1115, RCC7079, RCC7080, RCC7081, RCC7082, RCC7083, RCC7084, RCC7085}, issn = {2073-4409}, doi = {10.3390/cells10030664}, url = {https://www.mdpi.com/2073-4409/10/3/664}, author = {Thomy, Julie and Sanchez, Fr{\'e}d{\'e}ric and Gut, Marta and Cruz, Fernando and Alioto, Tyler and Piganeau, Gwenael and Grimsley, Nigel and Yau, Sheree} } @article {fernandes_comparative_2021, title = {Comparative lipidomic analysis of Chlorella stigmatophora and Hemiselmis cf. andersenii in response to nitrogen-induced changes}, journal = {Algal Research}, volume = {58}, year = {2021}, pages = {102417}, abstract = {The current focus of algae biotechnology is the production of high-value lipids, and its improvement by employing abiotic perturbations such as nitrogen-induced changes. In the present study, the growth dynamics, nitrogen uptake, pigments, and lipid composition of Chlorellla stigmatophora and Hemiselmis cf. andersenii were studied, in response to low (LN), medium (MN) and high (HN) nitrogen supplementations. Both microalgae responded to increased nitrogen levels by increasing their nitrogen uptake rate and pigment content. However, for lipid accumulation, C. stigmatophora presented a different pattern (LN: 16.56\% > MN: 11.51\% > HN: 10.95\%) to that of H. cf. andersenii (MN: 15.37\% > HN: 13.06\% > LN: 6.71\%). Untargeted gas chromatography{\textendash}mass spectrometry analysis allowed the visualization of the biochemical diversity of C. stigmatophora and H. cf. andersenii, as well as differences in lipid regulation upon nitrogen-induced changes among species. For instance, glycosyl sterols were only detected for C. stigmatophora samples grown under MN and HN conditions. Moreover, lipid analysis of H. cf. andersenii, before and after alkaline hydrolysis, suggests that wax esters play a key role in the response of this microalga to high nitrogen levels. The cultivation of H. cf. andersenii at MN and HN was shown to be ideal for providing a rich source of ω3 and polyunsaturated fatty acids for nutraceutical purposes. The hierarchical cluster analysis showed the differential intra- and interspecific effects of nitrogen on lipid composition. The diverse ways by which both microalgae responded to nitrogen-induced changes highlighted the influence of phylogeny on the carbon flux through metabolic networks, and accumulation.}, keywords = {cf., Lipidome analysis, Nitrogen supplementation, Nutraceutical lipids, rcc, RCC661}, issn = {2211-9264}, doi = {10.1016/j.algal.2021.102417}, url = {https://www.sciencedirect.com/science/article/pii/S2211926421002368}, author = {Fernandes, Tom{\'a}sia and Ferreira, Artur and Cordeiro, Nereida} } @article {croteau_contrasting_2021, title = {Contrasting nonphotochemical quenching patterns under high light and darkness aligns with light niche occupancy in Arctic diatoms}, journal = {Limnology and Oceanography}, volume = {66}, number = {S1}, year = {2021}, note = {_eprint: https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.11587}, pages = {S231{\textendash}S245}, abstract = {Over the seasons, Arctic diatom species occupy shifting habitats defined by contrasting light climates, constrained by snow and ice cover dynamics interacting with extreme photoperiod and solar angle variations. How Arctic diatom photoadaptation strategies differ across their heterogeneous light niches remains a poorly documented but crucial missing link to anticipate Arctic Ocean responses to shrinking sea-ice and increasing light. To address this question, we selected five Arctic diatom species with diverse life traits, representative of distinct light niches across the seasonal light environment continuum: from snow-covered dimly lit bottom ice to summer stratified waters. We studied their photoacclimation plasticity to two growth light levels and the subsequent responses of their nonphotochemical quenching (NPQ) and xanthophyll cycle to both dark incubations and light shifts. We deciphered NPQ and xanthophyll cycle tuning in darkness and their light-dependent induction kinetics, which aligned with species{\textquoteright} light niche occupancy. In ice-related species, NPQ was sustained in darkness and its induction was more reactive to moderate light shifts. Open-water species triggered strong NPQ induction in darkness and reached higher maximal NPQ under high light. Marginal ice zone species showed strong adaptation to light fluctuations with a dark response fine-tuned depending upon light history. We argue these traits are anchored in diverging photoadaption strategies fostering Arctic diatom success in their respective light niches.}, keywords = {RCC2046, RCC2278, RCC5318}, issn = {1939-5590}, doi = {10.1002/lno.11587}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.1002/lno.11587}, author = {Croteau, Dany and Gu{\'e}rin, S{\'e}bastien and Bruyant, Flavienne and Ferland, Joannie and Campbell, Douglas A. and Babin, Marcel and Lavaud, Johann} } @inbook {Paredes2021, title = {Cryopreservation of algae}, booktitle = {Cryopreservation and freeze-drying protocols}, volume = {2180}, year = {2021}, pages = {607{\textendash}621}, publisher = {Springer Science+Business Media, LLC}, organization = {Springer Science+Business Media, LLC}, keywords = {cryopreservation, macroalgae, Microalgae}, isbn = {978-1-07-160783-1}, doi = {10.1007/978-1-0716-0783-1_32}, url = {http://link.springer.com/10.1007/978-1-0716-0783-1_32}, author = {Paredes, Estefania and Ward, Angela and Probert, Ian and Gouhier, L{\'e}na and Campbell, Christine N.}, editor = {Wolkers, Willem F. and Oldenhof, Harriette} } @article {olusoji_cyanofilter_2021, title = {cyanoFilter: An R package to identify phytoplankton populations from flow cytometry data using cell pigmentation and granularity}, journal = {Ecological Modelling}, volume = {460}, year = {2021}, pages = {109743}, abstract = {Flow cytometry is often employed in ecology to measure traits and population size of bacteria and phytoplankton. This technique allows measuring millions of particles in a relatively small amount of time. However, distinguishing between different populations is not a straightforward task. Gating is a process in the identification of particles measured in flow cytometry. Gates can either be created manually using known characteristics of these particles, or by using automated clustering techniques. Available automated techniques implemented in statistical packages for flow cytometry are primarily developed for medicinal applications, while only two exist for phytoplankton. cyanoFilter is an R package built to identify phytoplankton populations from flow cytometry data. The package also integrates gating functions from two other automated algorithms. It also provides a gating accuracy test function that can be used to determine the accuracy of a desired gating function if monoculture flowcytometry data is available. The central algorithm in the package exploits observed pigmentation and granularity of phytoplankton cells. We demonstrate how its performance depends on strain similarity, using a model system of six cyanobacteria strains. Using the same system, we compare the performance of the central gating function in the package to similar functions in other packages.}, keywords = {Ecology, flow cytometry, Gating, phytoplankton, RCC2375, rcc2380, RCC2434, RCC2555, Software}, issn = {0304-3800}, doi = {10.1016/j.ecolmodel.2021.109743}, url = {https://www.sciencedirect.com/science/article/pii/S030438002100291X}, author = {Olusoji, Oluwafemi D. and Spaak, Jurg W. and Holmes, Mark and Neyens, Thomas and Aerts, Marc and De Laender, Frederik} } @article {fenizia_cysteinolic_2021, title = {Cysteinolic Acid Is a Widely Distributed Compatible Solute of Marine Microalgae}, journal = {Marine Drugs}, volume = {19}, number = {12}, year = {2021}, note = {Number: 12 Publisher: Multidisciplinary Digital Publishing Institute}, month = {dec}, pages = {683}, abstract = {Phytoplankton rely on bioactive zwitterionic and highly polar small metabolites with osmoregulatory properties to compensate changes in the salinity of the surrounding seawater. Dimethylsulfoniopropionate (DMSP) is a main representative of this class of metabolites. Salinity-dependent DMSP biosynthesis and turnover contribute significantly to the global sulfur cycle. Using advanced chromatographic and mass spectrometric techniques that enable the detection of highly polar metabolites, we identified cysteinolic acid as an additional widely distributed polar metabolite in phytoplankton. Cysteinolic acid belongs to the class of marine sulfonates, metabolites that are commonly produced by algae and consumed by bacteria. It was detected in all dinoflagellates, haptophytes, diatoms and prymnesiophytes that were surveyed. We quantified the metabolite in different phytoplankton taxa and revealed that the cellular content can reach even higher concentrations than the ubiquitous DMSP. The cysteinolic acid concentration in the cells of the diatom Thalassiosira weissflogii increases significantly when grown in a medium with elevated salinity. In contrast to the compatible solute ectoine, cysteinolic acid is also found in high concentrations in axenic algae, indicating biosynthesis by the algae and not the associated bacteria. Therefore, we add this metabolite to the family of highly polar metabolites with osmoregulatory characteristics produced by phytoplankton.}, keywords = {cysteinolic acid, diatoms, DMSP, ectoine, LC/MS analysis, osmoadaptation, osmoregulation, phytoplankton, RCC76, salinity}, doi = {10.3390/md19120683}, url = {https://www.mdpi.com/1660-3397/19/12/683}, author = {Fenizia, Simona and Weissflog, Jerrit and Pohnert, Georg} } @article {uwizeye_cytoklepty_2021, title = {Cytoklepty in the plankton: A host strategy to optimize the bioenergetic machinery of endosymbiotic algae}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {27}, year = {2021}, note = {Publisher: National Academy of Sciences Section: Biological Sciences}, month = {jul}, abstract = {Endosymbioses have shaped the evolutionary trajectory of life and remain ecologically important. Investigating oceanic photosymbioses can illuminate how algal endosymbionts are energetically exploited by their heterotrophic hosts and inform on putative initial steps of plastid acquisition in eukaryotes. By combining three-dimensional subcellular imaging with photophysiology, carbon flux imaging, and transcriptomics, we show that cell division of endosymbionts (Phaeocystis) is blocked within hosts (Acantharia) and that their cellular architecture and bioenergetic machinery are radically altered. Transcriptional evidence indicates that a nutrient-independent mechanism prevents symbiont cell division and decouples nuclear and plastid division. As endosymbiont plastids proliferate, the volume of the photosynthetic machinery volume increases 100-fold in correlation with the expansion of a reticular mitochondrial network in close proximity to plastids. Photosynthetic efficiency tends to increase with cell size, and photon propagation modeling indicates that the networked mitochondrial architecture enhances light capture. This is accompanied by 150-fold higher carbon uptake and up-regulation of genes involved in photosynthesis and carbon fixation, which, in conjunction with a ca.15-fold size increase of pyrenoids demonstrates enhanced primary production in symbiosis. Mass spectrometry imaging revealed major carbon allocation to plastids and transfer to the host cell. As in most photosymbioses, microalgae are contained within a host phagosome (symbiosome), but here, the phagosome invaginates into enlarged microalgal cells, perhaps to optimize metabolic exchange. This observation adds evidence that the algal metamorphosis is irreversible. Hosts, therefore, trigger and benefit from major bioenergetic remodeling of symbiotic microalgae with potential consequences for the oceanic carbon cycle. Unlike other photosymbioses, this interaction represents a so-called cytoklepty, which is a putative initial step toward plastid acquisition.}, keywords = {3D electron microscopy, oceanic plankton, Photosynthesis, rcc, rcc1383, single-cell transcriptomics, symbiosis}, issn = {0027-8424, 1091-6490}, doi = {10.1073/pnas.2025252118}, url = {https://www.pnas.org/content/118/27/e2025252118}, author = {Uwizeye, Clarisse and Brisbin, Margaret Mars and Gallet, Benoit and Chevalier, Fabien and LeKieffre, Charlotte and Schieber, Nicole L. and Falconet, Denis and Wangpraseurt, Daniel and Schertel, Lukas and Stryhanyuk, Hryhoriy and Musat, Niculina and Mitarai, Satoshi and Schwab, Yannick and Finazzi, Giovanni and Decelle, Johan} } @article {morais_detection_2021, title = {Detection of Alexandrium minutum dinoflagellate in environ- mental samples using electrochemical genosensor}, journal = {Chemistry Proceedings}, year = {2021}, pages = {7}, abstract = {Dinoflagellates are aquatic microorganisms that inhabit both salt and fresh waters. These microorganisms are mostly harmless, however, under certain conditions, some species rapidly reproduce forming water blooms that not only discolor the waters but also compromise the health of every organism in the vicinity, as some dinoflagellates produce potent toxins deemed unsafe for human health (e.g. Alexandrium minutum). In this work, a disposable electrochemical genosensor for the detection of the toxic dinoflagellate Alexandrium minutum was developed. The analytical platform methodology consisted in a sandwich format heterogeneous hybridization of complementary DNA sequences assay. The 70 bp A. minutum-specific targeting probe, the 45 bp fluorescein isothiocyanate-labelled signaling DNA probe and the 25 bp thiolated-DNA-capture probe were designed, after analyzing public databases. To maximize the complementary DNA hybridization and to avoid the formation of strong secondary structures, a mixed mercaptohexanol (MCH) and self-assembled monolayer (SAM) A. minutum-specific DNA-capture probe was immobilized onto disposable screen-printed gold electrodes (SPGE). Using chronoamperometric measurements, the enzymatic amplification of the electrochemical signal was obtained with a concentration range from 0.12 to 1.0 nM, a LD of 24.78 pM with a RSD < 5.2 \%. This electrochemical genosensor was successfully applied to the selective analysis of the targeted A. minutum specific region of denatured genomic DNA, extracted from toxic dinoflagellates present in the Atlantic Ocean.}, keywords = {? No DOI found, RCC3029}, author = {Morais, Stephanie L and Barros, Piedade and Santos, Marlene and Delerue-Matos, Cristina and Gomes, Andreia C and Barroso, M F{\'a}tima} } @article {robla_determination_2021, title = {Determination of the efficiency of filtration of cultures from microalgae and bacteria using hollow fiber filters}, journal = {Environmental Science: Water Research \& Technology}, volume = {7}, number = {7}, year = {2021}, note = {Publisher: The Royal Society of Chemistry}, month = {jul}, pages = {1230{\textendash}1239}, abstract = {The most important question in sampling is {\textquotedblleft}Is the sample representative of the target population?{\textquotedblright} This question is necessary to understand how valid the sample taken is to the original population and if generalizations can be made from the sample. Samples taken for water quality measurement range from 1 mL for bacterial contamination to 100 mL or up to 1000 L for protozoan parasites. With larger samples taken, the confidence in detecting rare events increases dramatically. Here we illustrate that hollow fiber filters as routinely used for kidney dialysis can be adapted for environmental use. The filters retain all organisms down to viral particles and organic matter above 70 kDA, the molecular cutoff for urea, one of the waste products removed in kidney dialysis. With these filters, 50 liters of water can be filtered in about 90 minutes. Backflush of the filters recovers viable cells with minimal cell lysis that can be processed downstream for molecular analysis. Recovery rates were as high as 89\% and 75\% for phytoplankton and bacteria, respectively.}, keywords = {rcc, RCC1507}, issn = {2053-1419}, doi = {10.1039/D0EW00927J}, url = {https://pubs.rsc.org/en/content/articlelanding/2021/ew/d0ew00927j}, author = {Robla, J. and Garc{\'\i}a-Hierrro, J. and Alguacil, F. J. and Dittami, S. M. and Marie, D. and Villa, E. and Deragon, E. and Guillebault, D. and Mengs, G. and Medlin, L. K.} } @mastersthesis {wislon_development_2021, title = {Development of automated nucleic acid technologies for marine point of sample diagnostics}, year = {2021}, school = {University of Southampton}, type = {phd}, address = {Southampton}, keywords = {RCC1513}, url = {https://eprints.soton.ac.uk/447354/1/Wilson_Matthew_Thesis_final_Jan21.pdf}, author = {Wislon, Matthew} } @article {zhang_development_2021, title = {Development of high-resolution chloroplast markers for intraspecific phylogeographic studies of Phaeocystis globosa}, journal = {Journal of Oceanology and Limnology}, volume = {39}, number = {2}, year = {2021}, month = {mar}, pages = {508{\textendash}524}, abstract = {Phaeocystis globosa is an important harmful algal bloom causative species distributing widely in temperate and tropical coastal waters in the world. The morphological, physiological, and biochemical characteristics are different among geographic strains, which can not be distinguished with nuclear ribosomal DNA markers at present. Therefore, the genetic distance and phylogeographic relationships of nuclear 28S rDNA D1{\textendash}D2 and ITS regions, and three chloroplast intergenic spacers (petN-trnS1, trnM1-psbA, and rbcS-rpl27) were analyzed and compared among 13 strains of P. globosa isolated from the Pacific Ocean and Atlantic Ocean in this study. In addition, the nucleotide polymorphisms of 28S rDNA D1{\textendash}D2, ITS, and rbcS-rpl27 regions were evaluated in two P. globosa strains. The various levels of nucleotide polymorphism were in the nuclear 28S rDNA D1{\textendash}D2 region and ITS region, but no polymorphism was in the chloroplast rbcS-rpl27 intergenic spacer. A reasonable intraspecific phylogeographic relationship was presented by rbcS-rpl27 intergenic spacer, which had the strongest distinction to geographic strains compared to those of 28S rDNA D1{\textendash}D2 and ITS regions. In the phylogenetic tree of rbcS-rpl27 intergenic spacer, the two strains from the North Sea of the Atlantic Ocean were divided firstly from the species of P. globosa, and then formed an independent clade, while the other Atlantic strains and all of Pacific strains joined up to build the other clade. It was implied that at least two genetically distant populations of P. globosa existed in the Atlantic coastal regions. This study provided a high-resolution chloroplast marker to analyze intraspecific phylogeographic populations of P. globosa, and preliminarily clarified the genetic relationships of the Pacific and Atlantic strains of P. globosa.}, keywords = {RCC2055, RCC736}, issn = {2096-5508, 2523-3521}, doi = {10.1007/s00343-020-9304-5}, url = {https://link.springer.com/10.1007/s00343-020-9304-5}, author = {Zhang, Qingchun and Niu, Zhuang and Wang, Jinxiu and Liu, Chao and Kong, Fanzhou and Hu, Xiaokun and Zhao, Jiayu and Yu, Rencheng} } @article {long_dinophyceae_2021, title = {Dinophyceae can use exudates as weapons against the parasite Amoebophrya sp. (Syndiniales)}, journal = {ISME Communications}, volume = {1}, number = {1}, year = {2021}, note = {Bandiera_abtest: a Cg_type: Nature Research Journals Number: 1 Primary_atype: Research Publisher: Nature Publishing Group Subject_term: Microbial ecology;Plant ecology;Water microbiology Subject_term_id: microbial-ecology;plant-ecology;water-microbiology}, pages = {1{\textendash}10}, abstract = {Parasites in the genus Amoebophrya sp. infest dinoflagellate hosts in marine ecosystems and can be determining factors in the demise of blooms, including toxic red tides. These parasitic protists, however, rarely cause the total collapse of Dinophyceae blooms. Experimental addition of parasite-resistant Dinophyceae (Alexandrium minutum or Scrippsiella donghaienis) or exudates into a well-established host-parasite coculture (Scrippsiella acuminata-Amoebophrya sp.) mitigated parasite success and increased the survival of the sensitive host. This effect was mediated by waterborne molecules without the need for a physical contact. The strength of the parasite defenses varied between dinoflagellate species, and strains of A. minutum and was enhanced with increasing resistant host cell concentrations. The addition of resistant strains or exudates never prevented the parasite transmission entirely. Survival time of Amoebophrya sp. free-living stages (dinospores) decreased in presence of A. minutum but not of S. donghaienis. Parasite progeny drastically decreased with both species. Integrity of the dinospore membrane was altered by A. minutum, providing a first indication on the mode of action of anti-parasitic molecules. These results demonstrate that extracellular defenses can be an effective strategy against parasites that protects not only the resistant cells producing them, but also the surrounding community.}, keywords = {microbial ecology, Plant ecology, rcc, RCC1627, RCC4383, RCC4714, RCC749, Water microbiology}, issn = {2730-6151}, doi = {10.1038/s43705-021-00035-x}, url = {http://www.nature.com/articles/s43705-021-00035-x}, author = {Long, Marc and Marie, Dominique and Szymczak, Jeremy and Toullec, Jordan and Bigeard, Estelle and Sourisseau, Marc and Le Gac, Micka{\"e}l and Guillou, Laure and Jauzein, C{\'e}cile} } @booklet {marc_dinophyceae_2021, title = {Dinophyceae use exudates as weapons against the parasite Amoebophrya sp. (Syndiniales)}, year = {2021}, note = {Company: Cold Spring Harbor Laboratory Distributor: Cold Spring Harbor Laboratory Label: Cold Spring Harbor Laboratory Section: New Results Type: article}, month = {jan}, pages = {2021.01.05.425281}, abstract = {Parasites of the genus Amoebophrya sp. are important contributors to marine ecosystems and can be determining factors in the demise of blooms of Dinophyceae, including microalgae commonly responsible for toxic red tides. Yet they rarely lead to the total collapse of Dinophyceae blooms. The addition of resistant Dinophyceae (Alexandrium minutum or Scrippsiella donghaienis) or their exudate into a well-established host-parasite culture (Scrippsiella acuminata-Amoebophrya sp.) mitigated the success of the parasite and increased the survival of the sensitive host. Effect were mediated via water-borne molecules without the need of a physical contact. Severity of the anti-parasitic defenses fluctuated depending on the species, the strain and its concentration, but never totally prevented the parasite transmission. The survival time of Amoebophrya sp. free-living stages (dinospores) decreased in presence of A. minutum but not of S. donghaienis. The progeny drastically decreased with both species. Integrity of the membrane of dinospores was altered by A. minutum which provided a first indication on the mode of action of these anti-parasitic molecules. These results demonstrate that extracellular defenses are an effective strategy against parasites that does not only protect the resistant cells but also have the potential to affect the whole surrounding community.}, keywords = {rcc, RCC1627, RCC4383, RCC4714, RCC749}, doi = {10.1101/2021.01.05.425281}, url = {https://www.biorxiv.org/content/10.1101/2021.01.05.425281v1}, author = {Marc, Long and Dominique, Marie and Jeremy, Szymczak and Jordan, Toullec and Estelle, Bigeard and Marc, Sourisseau and Mickael, Le Gac and Laure, Guillou and C{\'e}cile, Jauzein} } @article {xie_disentangling_2021, title = {Disentangling the Effects of Ocean Carbonation and Acidification on Elemental Contents and Macromolecules of the Coccolithophore Emiliania huxleyi}, journal = {Frontiers in Microbiology}, volume = {12}, year = {2021}, pages = {3188}, abstract = {Elemental contents change with shifts in macromolecular composition of marine phytoplankton. Recent studies focus on the responses of elemental contents of coccolithophores, a major calcifying phytoplankton group, to changing carbonate chemistry, caused by the dissolution of anthropogenically derived CO2 into the surface ocean. However, the effects of changing carbonate chemistry on biomacromolecules, such as protein and carbohydrate of coccolithophores, are less documented. Here, we disentangled the effects of elevated dissolved inorganic carbon (DIC) concentration (900 to 4,930μmolkg-1) and reduced pH value (8.04 to 7.70) on physiological rates, elemental contents, and macromolecules of the coccolithophore Emiliania huxleyi. Compared to present DIC concentration and pH value, combinations of high DIC concentration and low pH value (ocean acidification) significantly increased pigments content, particulate organic carbon (POC), and carbohydrate content and had less impact on growth rate, maximal relative electron transport rate (rETRmax), particulate organic nitrogen (PON), and protein content. In high pH treatments, elevated DIC concentration significantly increased growth rate, pigments content, rETRmax, POC, particulate inorganic carbon (PIC), protein, and carbohydrate contents. In low pH treatments, the extents of the increase in growth rate, pigments and carbohydrate content were reduced. Compared to high pH value, under low DIC concentration, low pH value significantly increased POC and PON contents and showed less impact on protein and carbohydrate contents; however, under high DIC concentration, low pH value significantly reduced POC, PON, protein, and carbohydrate contents. These results showed that reduced pH counteracted the positive effects of elevated DIC concentration on growth rate, rETRmax, POC, PON, carbohydrate, and protein contents. Elevated DIC concentration and reduced pH acted synergistically to increase the contribution of carbohydrate{\textendash}carbon to POC, and antagonistically to affect the contribution of protein{\textendash}nitrogen to PON, which further shifted the carbon/nitrogen ratio of E. huxleyi.}, keywords = {rcc, RCC1266}, issn = {1664-302X}, doi = {10.3389/fmicb.2021.737454}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2021.737454}, author = {Xie, Emei and Xu, Kui and Li, Zhengke and Li, Wei and Yi, Xiangqi and Li, Hongzhou and Han, Yonghe and Zhang, Hong and Zhang, Yong} } @article {pan_effects_2021, title = {Effects of Epibiotic Diatoms on the Productivity of the Calanoid Copepod Acartia tonsa (Dana) in Intensive Aquaculture Systems}, journal = {Frontiers in Marine Science}, volume = {8}, year = {2021}, pages = {1386}, abstract = {We evaluated here the effects of the epibiotic diatom Tabularia sp. on the productivity of the calanoid copepod Acartia tonsa (Dana) for assessing their risk on copepod intensive aquaculture industry for the provision of live feed. In the first experiment, uninfested and intensively infested females were cultivated individually for the assessment of egg production. Intensively infested females appeared to have a significantly lower egg production (5.0{\textendash}9.0 eggs/female/d) than uninfested females (22.0{\textendash}26.0 eggs/female/d) during 5 consecutive days. In the second experiment, effects of culture densities on diatom epibiosis were investigated in 9 L cultures at three different densities (200, 400, and 600 ind. L{\textendash}1). Another culture at higher volume (250 L) and lowest density (200 ind. L{\textendash}1) was also carried out to test the effect of culture volume on diatom epibiosis. The infestation rate (\%), infestation intensity (ratio of surface diatom coverage levels, classified as levels 0{\textendash}3) and daily egg harvest rate (number of harvested eggs per day per liter) were evaluated among the four culture populations. The copepods had higher infestation rate (53.69{\textendash}60.14\%) and intensity rate (high ratios at level 2 and 3) when the densities were increased from 200 ind./L to 400 and 600 ind./L. Although egg harvest increased with increasing culture density, it seemed that the diatom-infested A. tonsa population reach a saturated egg production when the density was higher than 400 ind./L. Nevertheless, the differences of culture volumes (250 and 9 L) appeared to be not to have any effect when the copepods were cultivated at the same density (200 ind./L). This study reveals for the first time that the epibiosis of the diatom Tabularia sp. reduces the individual egg production, and egg harvest rate in high-density culture of the copepod A. tonsa. Our findings implicate that diatom epibiosis should be avoid in copepod intensive culture systems.}, keywords = {rcc, RCC350}, issn = {2296-7745}, doi = {10.3389/fmars.2021.728779}, url = {https://www.frontiersin.org/article/10.3389/fmars.2021.728779}, author = {Pan, Yen-Ju and Wang, Wei-Lung and Hwang, Jiang-Shiou and Souissi, Sami} } @article {eich_effects_2021, title = {Effects of UV Radiation on the Chlorophyte Micromonas polaris Host{\textendash}Virus Interactions and MpoV-45T Virus Infectivity}, journal = {Microorganisms}, volume = {9}, year = {2021}, pages = {2429}, abstract = {Polar seas are under threat of enhanced UV-radiation as well as increasing shipping activities. Considering the ecological importance of marine viruses, it is timely to study the impact of UV-AB on Arctic phytoplankton host{\textendash}virus interactions and also test the efficacy of ballast water (BW) UV-C treatment on virus infectivity. This study examined the effects of: (i) ecologically relevant doses of UV-AB radiation on Micromonas polaris RCC2258 and its virus MpoV-45T, and (ii) UV-C radiation (doses 25{\textendash}800 mJ cm-2) on MpoV-45T and other temperate algal viruses. Total UV-AB exposure was 6, 12, 28 and 48 h (during the light periods, over 72 h total). Strongest reduction in algal growth and photosynthetic efficiency occurred for 28 and 48 h UV-AB treatments, and consequently the virus production rates and burst sizes were reduced by more than half (compared with PAR-only controls). For the shorter UV-AB exposed cultures, negative effects by UV (especially Fv/Fm) were overcome without impacting virus proliferation. To obtain the BW desired log-4 reduction in virus infectivity, a UV-C dose of at least 400 mJ cm-2 was needed for MpoV-45T and the temperate algal viruses. This is higher than the commonly used dose of 300 mJ cm-2 in BW treatment.}, keywords = {RCC2258}, doi = {10.3390/microorganisms9122429}, author = {Eich, Charlotte} } @article {benites_evolutionary_2021, title = {Evolutionary Genomics of Sex-Related Chromosomes at the Base of the Green Lineage}, journal = {Genome Biology and Evolution}, volume = {13}, number = {10}, year = {2021}, pages = {evab216}, abstract = {Although sex is now accepted as a ubiquitous and ancestral feature of eukaryotes, direct observation of sex is still lacking in most unicellular eukaryotic lineages. Evidence of sex is frequently indirect and inferred from the identification of genes involved in meiosis from whole genome data and/or the detection of recombination signatures from genetic diversity in natural populations. In haploid unicellular eukaryotes, sex-related chromosomes are named mating-type (MTs) chromosomes and generally carry large genomic regions where recombination is suppressed. These regions have been characterized in Fungi and Chlorophyta and determine gamete compatibility and fusion. Two candidate MT{\th} and MT{\`A} alleles, spanning 450{\textendash}650 kb, have recently been described in Ostreococcus tauri, a marine phytoplanktonic alga from the Mamiellophyceae class, an early diverging branch in the green lineage. Here, we investigate the architecture and evolution of these candidate MT{\th} and MT{\`A} alleles. We analyzed the phylogenetic profile and GC content of MT gene families in eight different genomes whose divergence has been previously estimated at up to 640 Myr, and found evidence that the divergence of the two MT alleles predates speciation in the Ostreococcus genus. Phylogenetic profiles of MT transspecific polymorphisms in gametologs disclosed candidate MTs in two additional species, and possibly a third. These Mamiellales MT candidates are likely to be the oldest mating-type loci described to date, which makes them fascinating models to investigate the evolutionary mechanisms of haploid sex determination in eukaryotes.}, keywords = {RCC1105, RCC1115, RCC2590, RCC299, rcc3401, RCC4221, RCC809, RCC834}, issn = {1759-6653}, doi = {10.1093/gbe/evab216}, url = {https://academic.oup.com/gbe/article/doi/10.1093/gbe/evab216/6380139}, author = {Benites, Luis Felipe and Bucchini, Fran{\c c}ois and Sanchez-Brosseau, Sophie and Grimsley, Nigel and Vandepoele, Klaas and Piganeau, Gwenael}, editor = {Wolfe, Kenneth} } @article {bock_experimental_2021, title = {Experimental identification and in silico prediction of bacterivory in green algae}, journal = {The ISME Journal}, year = {2021}, note = {Publisher: Nature Publishing Group}, month = {mar}, pages = {1{\textendash}14}, abstract = {While algal phago-mixotrophs play a major role in aquatic microbial food webs, their diversity remains poorly understood. Recent studies have indicated several species of prasinophytes, early diverging green algae, to be able to consume bacteria for nutrition. To further explore the occurrence of phago-mixotrophy in green algae, we conducted feeding experiments with live fluorescently labeled bacteria stained with CellTracker Green CMFDA, heat-killed bacteria stained with 5-(4,6-dichlorotriazin-2-yl) aminofluorescein (DTAF), and magnetic beads. Feeding was detected via microscopy and/or flow cytometry in five strains of prasinophytes when provided with live bacteria: Pterosperma cristatum NIES626, Pyramimonas parkeae CCMP726, Pyramimonas parkeae NIES254, Nephroselmis pyriformis RCC618, and Dolichomastix tenuilepis CCMP3274. No feeding was detected when heat-killed bacteria or magnetic beads were provided, suggesting a strong preference for live prey in the strains tested. In parallel to experimental assays, green algal bacterivory was investigated using a gene-based prediction model. The predictions agreed with the experimental results and suggested bacterivory potential in additional green algae. Our observations underline the likelihood of widespread occurrence of phago-mixotrophy among green algae, while additionally highlighting potential biases introduced when using prey proxy to evaluate bacterial ingestion by algal cells.}, keywords = {RCC180, RCC3375, RCC369, RCC618}, issn = {1751-7370}, doi = {10.1038/s41396-021-00899-w}, url = {http://www.nature.com/articles/s41396-021-00899-w}, author = {Bock, Nicholas A. and Charvet, Sophie and Burns, John and Gyaltshen, Yangtsho and Rozenberg, Andrey and Duhamel, Solange and Kim, Eunsoo} } @article {pinto_features_2021, title = {Features of the Opportunistic Behaviour of the Marine Bacterium Marinobacter algicola in the Microalga Ostreococcus tauri Phycosphere}, journal = {Microorganisms}, volume = {9}, year = {2021}, pages = {1777}, abstract = {Although interactions between microalgae and bacteria are observed in both natural environment and the laboratory, the modalities of coexistence of bacteria inside microalgae phyco-spheres in laboratory cultures are mostly unknown. Here, we focused on well-controlled cultures of the model green picoalga Ostreococcus tauri and the most abundant member of its phycosphere, Marinobacter algicola. The prevalence of M. algicola in O. tauri cultures raises questions about how this bacterium maintains itself under laboratory conditions in the microalga culture. The results showed that M. algicola did not promote O. tauri growth in the absence of vitamin B12 while M. algicola depended on O. tauri to grow in synthetic medium, most likely to obtain organic carbon sources provided by the microalgae. M. algicola grew on a range of lipids, including triacylglycerols that are known to be produced by O. tauri in culture during abiotic stress. Genomic screening revealed the absence of genes of two particular modes of quorum-sensing in Marinobacter genomes which refutes the idea that these bacterial communication systems operate in this genus. To date, the {\textquoteright}opportunistic{\textquoteright} behaviour of M. algicola in the laboratory is limited to several phytoplanktonic species including Chlorophyta such as O. tauri. This would indicate a preferential occurrence of M. algicola in association with these specific microalgae under optimum laboratory conditions.}, keywords = {RCC4221}, doi = {10.3390/microorganisms9081777}, author = {Pinto, Jordan and Lami, Rapha{\"e}l and Krasovec, Marc and Grimaud, R{\'e}gis and Urios, Laurent and Lupette, Josselin and Escande, Marie-Line and Sanchez, Fr{\'e}d{\'e}ric and Intertaglia, Laurent and Grimsley, Nigel and Piganeau, Gwenael and Sanchez, Sophie} } @article {geffroy_sxta4_2021, title = {From the sxtA4 Gene to Saxitoxin Production: What Controls the Variability Among Alexandrium minutum and Alexandrium pacificum Strains?}, journal = {Frontiers in Microbiology}, volume = {12}, year = {2021}, pages = {613199}, abstract = {Paralytic shellfish poisoning (PSP) is a human foodborne syndrome caused by the consumption of shellfish that accumulate paralytic shellfish toxins (PSTs, saxitoxin group). In PST-producing dinoflagellates such as Alexandrium spp., toxin synthesis is encoded in the nuclear genome via a gene cluster (sxt). Toxin production is supposedly associated with the presence of a 4th domain in the sxtA gene (sxtA4), one of the core genes of the PST gene cluster. It is postulated that gene expression in dinoflagellates is partially constitutive, with both transcriptional and post-transcriptional processes potentially co-occurring. Therefore, gene structure and expression mode are two important features to explore in order to fully understand toxin production processes in dinoflagellates. In this study, we determined the intracellular toxin contents of twenty European Alexandrium minutum and Alexandrium pacificum strains that we compared with their genome size and sxtA4 gene copy numbers. We observed a significant correlation between the sxtA4 gene copy number and toxin content, as well as a moderate positive correlation between the sxtA4 gene copy number and genome size. The 18 toxic strains had several sxtA4 gene copies (9{\textendash}187), whereas only one copy was found in the two observed non-toxin producing strains. Exploration of allelic frequencies and expression of sxtA4 mRNA in 11 A. minutum strains showed both a differential expression and specific allelic forms in the non-toxic strains compared with the toxic ones. Also, the toxic strains exhibited a polymorphic sxtA4 mRNA sequence between strains and between gene copies within strains. Finally, our study supported the hypothesis of a genetic determinism of toxin synthesis (i.e., the existence of several genetic isoforms of the sxtA4 gene and their copy numbers), and was also consistent with the hypothesis that constitutive gene expression and moderation by transcriptional and post-transcriptional regulation mechanisms are the cause of the observed variability in the production of toxins by A. minutum.}, keywords = {RCC2644, RCC2645, RCC3327, RCC4871, RCC4872, RCC4890, RCC7037, RCC7038, RCC7039}, issn = {1664-302X}, doi = {10.3389/fmicb.2021.613199}, url = {https://www.frontiersin.org/articles/10.3389/fmicb.2021.613199/full}, author = {Geffroy, Sol{\`e}ne and Lechat, Marc-Marie and Le Gac, Micka{\"e}l and Rovillon, Georges-Augustin and Marie, Dominique and Bigeard, Estelle and Malo, Florent and Amzil, Zouher and Guillou, Laure and Caruana, Amandine M. N.} } @article {Wang2021, title = {Group 2i Isochrysidales produce characteristic alkenones reflecting sea ice distribution}, journal = {Nature Communications}, volume = {12}, number = {1}, year = {2021}, note = {Publisher: Springer US tex.mendeley-tags: RCC107,RCC1195,RCC1334,RCC5486}, month = {dec}, pages = {15}, abstract = {Alkenones are biomarkers produced solely by algae in the order Isochrysidales that have been used to reconstruct sea surface temperature (SST) since the 1980s. However, alkenone-based SST reconstructions in the northern high latitude oceans show significant bias towards warmer temperatures in core-tops, diverge from other SST proxies in down core records, and are often accompanied by anomalously high relative abundance of the C 37 tetra-unsaturated methyl alkenone (\%C 37:4 ). Elevated \%C 37:4 is widely interpreted as an indicator of low sea surface salinity from polar water masses, but its biological source has thus far remained elusive. Here we identify a lineage of Isochrysidales that is responsible for elevated C 37:4 methyl alkenone in the northern high latitude oceans through next-generation sequencing and lab-culture experiments. This Isochrysidales lineage co-occurs widely with sea ice in marine environments and is distinct from other known marine alkenone-producers, namely Emiliania huxleyi and Gephyrocapsa oceanica . More importantly, the \%C 37:4 in seawater filtered particulate organic matter and surface sediments is significantly correlated with annual mean sea ice concentrations. In sediment cores from the Svalbard region, the \%C 37:4 concentration aligns with the Greenland temperature record and other qualitative regional sea ice records spanning the past 14 kyrs, reflecting sea ice concentrations quantitatively. Our findings imply that \%C 37:4 is a powerful proxy for reconstructing sea ice conditions in the high latitude oceans on thousand- and, potentially, on million-year timescales.}, keywords = {RCC107, RCC1195, RCC1334, RCC5486}, issn = {2041-1723}, doi = {10.1038/s41467-020-20187-z}, url = {http://dx.doi.org/10.1038/s41467-020-20187-z http://www.nature.com/articles/s41467-020-20187-z}, author = {Wang, Karen Jiaxi and Huang, Yongsong and Majaneva, Markus and Belt, Simon T. and Liao, Sian and Novak, Joseph and Kartzinel, Tyler R. and Herbert, Timothy D. and Richter, Nora and Cabedo-Sanz, Patricia} } @article {zhang_growth-dependent_2021, title = {Growth-dependent changes in elemental stoichiometry and macromolecular allocation in the coccolithophore Emiliania huxleyi under different environmental conditions}, journal = {Limnology and Oceanography}, volume = {66}, number = {8}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/lno.11854}, pages = {2999{\textendash}3009}, abstract = {The growth rate hypothesis (GRH) posits an increase in ribosomal ribonucleic acid (RNA) content, and therefore cellular phosphorus (P), with increasing growth rate. There is evidence that the GRH may not apply to phytoplankton under all conditions. Here, we experimentally controlled four conditions (light, temperature, pH, and CO2) to alter the growth rate of Emiliania huxleyi, a biogeochemically important coccolithophorid, and monitored changes in RNA, protein, and carbohydrate content. We show that an increase in growth rate caused by increasing light, pH, and CO2 resulted in increased RNA per unit of organic carbon (RNA : POC), but that increasing temperature, leading to increase of growth rate, resulted in a decrease in RNA : POC. Protein per unit of organic carbon (protein : POC) increased in our increased temperature, pH, and CO2 treatments that increased growth rate, but there was little change in protein : POC in our light treatment despite it inducing the same increase in growth rate. Carbohydrate per unit of organic carbon (Carbohydrate : POC) increased with growth rate under increased light and CO2 but did not vary significantly in the temperature or pH treatments. These results indicate that physiological acclimation to specific environmental conditions can lead to contrasting patterns in RNA, protein, and carbohydrate composition and therefore contrasting changes in carbon : nitrogen : phosphorus ratios with growth rate in E. huxleyi.}, keywords = {rcc, RCC1266}, issn = {1939-5590}, doi = {10.1002/lno.11854}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lno.11854}, author = {Zhang, Yong and Li, Zhengke and Schulz, Kai G. and Hu, Yingyu and Irwin, Andrew J. and Finkel, Zoe V.} } @article {Magalhaes2018, title = {Hemiselmis aquamarina sp . nov . (Cryptomonadales , Cryptophyceae), a cryptomonad with a novel phycobiliprotein type (Cr-PC 564)}, journal = {Protist}, volume = {in press}, year = {2021}, keywords = {RCC4102, RCC5634, to add}, doi = {10.1016/j.protis.2021.125832}, url = {https://doi.org/10.1016/j.protis.2021.125832}, author = {Magalh{\~a}es, Karoline and Lopes dos Santos, Adriana and Vaulot, Daniel and de Oliveira, Mariana Cabral} } @article {tostevin_influence_2021, title = {The influence of elevated SiO2(aq) on intracellular silica uptake and microbial metabolism}, journal = {Geobiology}, volume = {n/a}, number = {n/a}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12442}, abstract = {Microbes are known to accumulate intracellular SiO2(aq) up to 100s of mmol/l from modern seawater (SiO2(aq) <100 {\textmu}mol/l), despite having no known nutrient requirement for Si. Before the evolution of siliceous skeletons, marine silica concentrations were likely an order of magnitude higher than the modern ocean, raising the possibility that intracellular SiO2(aq) accumulation interfered with normal cellular function in non-silicifying algae. Yet, because few culturing studies have isolated the effects of SiO2(aq) at high concentration, the potential impact of elevated marine silica on early microbial evolution is unknown. Here, we test the influence of elevated SiO2(aq) on eukaryotic algae, as well as a prokaryote species. Our results demonstrate that under SiO2(aq) concentrations relevant to ancient seawater, intracellular Si accumulates to concentrations comparable to those found in siliceous algae such as diatoms. In addition, all eukaryotic algae showed a statistically significant response to the high-Si treatment, including reduced average cell sizes and/or a reduction in the maximum growth rate. In contrast, there was no consistent response to the high-Si treatment by the prokaryote species. Our results highlight the possibility that elevated marine SiO2(aq) may have been an environmental stressor during early eukaryotic evolution.}, keywords = {Archaean, culturing, microbial metabolism, Proterozoic, RCC1, RCC1216, rcc1512, RCC1547, rcc539, silica}, issn = {1472-4669}, doi = {10.1111/gbi.12442}, url = {http://onlinelibrary.wiley.com/doi/abs/10.1111/gbi.12442}, author = {Tostevin, Rosalie and Snow, Joseph T. and Zhang, Qiong and Tosca, Nicholas J. and Rickaby, Rosalind E. M.} } @article {Henry2021, title = {The influences of phytoplankton species, mineral particles and concentrations of dispersed oil on the formation and fate of marine oil-related aggregates}, journal = {Science of the Total Environment}, volume = {752}, year = {2021}, note = {Publisher: Elsevier B.V. tex.mendeley-tags: RCC1698,RCC1719,RCC290}, month = {jan}, pages = {141786}, abstract = {The formation and fallout of oil-related marine snow have been associated with interactions between dispersed oil and small marine particles, like phytoplankton and mineral particles. In these studies, the influences of phytoplankton species, mineral particle concentration, and oil concentration on the aggregation of oil in seawater (SW) were investigated. The experiments were performed in a low-turbidity carousel incubation system, using natural SW at 13 {\textdegree}C. Aggregation was measured by silhouette camera analyses, and oil compound group distribution and depletion by gas chromatography (GC-FID or GC{\textendash}MS). Aggregates with median sizes larger than 500 ??m in diameter were measured in the presence of dispersed oil and the phytoplankton species Thalassiosira rotula, Phaeocystis globosa, Skeletonema pseudocostatum, but not with the microalgae Micromonas pusilla. When mineral particles (diatomaceous earth) were incubated at different concentrations (5{\textendash}30 mg/L) with dispersed oil and S. pseudocostatum, the largest aggregates were measured at the lower mineral particle concentration (5 mg/L). Since dispersed oil rapidly dilutes in the marine water column, experiments were performed with oil concentrations of from 10 mg/L to 0.01 mg/L in the presence of S. pseudocostatum and diatomaceous earth. Aggregates larger than 500 ??m was measured only at the highest oil concentrations (10 mg/L). However, oil attachment to the marine particles were also measured at low oil concentrations (<=1 mg/L). Depletion of oil compound groups (n-alkanes, naphthalenes, PAHs, decalins) were measured at all oil concentrations, both in aggregate and water phases, with biodegradation as the expected main depletion process. These results showed that oil concentration may be important for oil-related marine snow formation, but that even oil droplets at low concentrations may attach to the particles and be transported by prevailing currents.}, keywords = {Aggregation, Dispersed oil, Marine snow, Mineral particles, phytoplankton, RCC1698, RCC1719, RCC290}, issn = {18791026}, doi = {10.1016/j.scitotenv.2020.141786}, author = {Henry, Ingrid A. and Netzer, Roman and Davies, Emlyn and Brakstad, Odd Gunnar} } @article {zhang_isotope_2021, title = {An isotope label method for empirical detection of carbonic anhydrase in the calcification pathway of the coccolithophore Emiliania huxleyi}, journal = {Geochimica et Cosmochimica Acta}, volume = {292}, year = {2021}, pages = {78{\textendash}93}, abstract = {Coccolithophores are a group of phytoplankton widely distributed in the ocean, which secrete extracellular calcite plates termed coccoliths. Coccoliths have been increasingly employed as an archive for geochemical, ecological and paleoclimate studies in recent years. A robust application of coccolith-based geochemical proxies relies on understanding the carbon acquisition strategies and the pathways of carbon supply for calcification. Carbonic anhydrase (CA) plays important roles in the carbon concentrating mechanism s of aquatic algae and potentially also in calcification. However, it is difficult to independently assess the role of CA in carbon supply for photosynthesis versus calcification. To fill this gap, we explored a new method to detect the CA activity inside coccolithophore. To achieve this, coccolithophores were cultured with oxygen and carbon isotope labeled dissolved inorganic carbon (DIC). By exploiting the different behavior of oxygen and carbon isotopes with (sea)water, this double label method can elucidate the significance of CA activity in the calcification pathway. Application of this method to Emiliania huxleyi shows that CA is present in the calcification pathway, and that there is no significant difference in the CA activity between a high and low CO2 treatment. However, under low CO2 treatment E. huxleyi enhanced the bicarbonate pumping rate on both cell and chloroplast membranes. This novel method could be performed on other species of coccolithophores in the future and have a potential to extend our knowledge on coccolith oxygen isotope vital effects.}, keywords = {Carbonic anhjydrase, ccm, coccolithophore, Isotopic labelling, rcc, rcc1258}, issn = {0016-7037}, doi = {10.1016/j.gca.2020.09.008}, url = {https://www.sciencedirect.com/science/article/pii/S0016703720305597}, author = {Zhang, Hongrui and Blanco-Ameijeiras, Sonia and Hopkinson, Brian M. and Bernasconi, Stefano M. and Mejia, Luz Maria and Liu, Chuanlian and Stoll, Heather} } @article {schapira_les_2021, title = {Les Efflorescences de Lepidodinium chlorophorum au large de la Loire et de la Vilaine : D{\'e}terminisme et cons{\'e}quences sur la qualit{\'e} des masses d{\textquoteright}eau c{\^o}ti{\`e}res}, year = {2021}, abstract = {Ce projet, organis{\'e} en trois actions, avait pour objectif de mieux {\'e}valuer les risques d{\textquoteright}eaux color{\'e}es vertes se produisant sur le secteur c{\^o}tier situ{\'e} au large de la Loire et de la Vilaine, en termes (i) de fr{\'e}quence de ces {\'e}pisodes, (ii) d{\textquoteright}abondance et (iii) de localisation des zones {\`a} risque. Action 1 : Am{\'e}lioration du recensement des eaux vertes {\`a} L. chlorophorum Action 2 : Optimisation de l{\textquoteright}estimation des abondances de L. chlorophorum Action 3 : Identification des zones {\`a} risque au large de la Loire et de la Vilaine.}, keywords = {? No DOI found, rcc, RCC1489}, url = {https://archimer.ifremer.fr/doc/00724/83598/}, author = {Schapira, Mathilde and Roux, Pauline and Andre, Coralie and Mertens, Kenneth and Bilien, Gwenael and Terre Terrillon, Aouregan and Le Gac-Abernot, Chantal and Siano, Raffaele and Qu{\'e}r{\'e}, Julien and Bizzozero, Lucie and Bonneau, Francoise and Bouget, Jean-Francois and Cochennec-Laureau, Nathalie and Collin, Karine and Fortune, Mireille and Gabellec, Raoul and Le Merrer, Yoann and Manach, Soazig and Pierre-Duplessix, Olivier and Retho, Michael and Schmitt, Anne and Souchu, Philippe and Stachowski-Haberkorn, Sabine} } @inbook {reddy_marine_2021, title = {Marine Biodiscovery in a Changing World}, booktitle = {Progress in the Chemistry of Organic Natural Products 116}, series = {Progress in the Chemistry of Organic Natural Products}, year = {2021}, pages = {1{\textendash}36}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {The term {\textquotedblleft}marine biodiscovery{\textquotedblright} has been recently been adopted to describe the area of marine natural products dedicated to the search of new drugs. Several maritime countries such as Australia, New Zealand, South Korea, and Japan as well as some European countries have invested significantly in this area of research over the last 50 years. In the late 2000s, research in this field has received significant interest and support in Ireland for exploring new marine bioresources from the nutrient-rich waters of the Northeastern Atlantic Ocean. Despite undeniable success exemplified by the marketing of new drugs, especially in oncology, the integration of new technical but also environmental aspects should be considered. Indeed, global change, particularly in our oceans, such as climate change, biodiversity loss, and the emergence of microbial pathogens, not only affects the environment but ultimately contributes to social inequalities. In this contribution, new avenues and best practices are proposed, such as the development of biorepositories and shared data for the future of marine biodiscovery research. The extension of this type of scientific work will allow humanity to finally make the optimum use of marine bioresources.}, keywords = {Bioprospecting, Biorepositories, Data management system, Marine biodiscovery, Marine natural products, Screenings, taxonomy}, isbn = {978-3-030-80560-9}, doi = {10.1007/978-3-030-80560-9_1}, url = {https://doi.org/10.1007/978-3-030-80560-9_1}, author = {Reddy, Maggie M. and Jennings, Laurence and Thomas, Olivier P.}, editor = {Kinghorn, A. Douglas and Falk, Heinz and Gibbons, Simon and Asakawa, Yoshinori and Liu, Ji-Kai and Dirsch, Verena M.} } @article {six_marine_2021, title = {Marine Synechococcus picocyanobacteria: Light utilization across latitudes}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {38}, year = {2021}, note = {Publisher: National Academy of Sciences Section: Biological Sciences}, abstract = {

The most ubiquitous cyanobacteria, Synechococcus, have colonized different marine thermal niches through the evolutionary specialization of lineages adapted to different ranges of temperature seawater. We used the strains of Synechococcus temperature ecotypes to study how light utilization has evolved in the function of temperature. The tropical Synechococcus (clade II) was unable to grow under 16 {\textdegree}C but, at temperatures \>25 {\textdegree}C, induced very high growth rates that relied on a strong synthesis of the components of the photosynthetic machinery, leading to a large increase in photosystem cross-section and electron flux. By contrast, the Synechococcus adapted to subpolar habitats (clade I) grew more slowly but was able to cope with temperatures \<10 {\textdegree}C. We show that growth at such temperatures was accompanied by a large increase of the photoprotection capacities using the orange carotenoid protein (OCP). Metagenomic analyzes revealed that Synechococcus natural communities show the highest prevalence of the ocp genes in low-temperature niches, whereas most tropical clade II Synechococcus have lost the gene. Moreover, bioinformatic analyzes suggested that the OCP variants of the two cold-adapted Synechococcus clades I and IV have undergone evolutionary convergence through the adaptation of the molecular flexibility. Our study points to an important role of temperature in the evolution of the OCP. We, furthermore, discuss the implications of the different metabolic cost of these physiological strategies on the competitiveness of Synechococcus in a warming ocean. This study can help improve the current hypotheses and models aimed at predicting the changes in ocean carbon fluxes in response to global warming.

}, keywords = {?? Invalid DOI, RCC2035, rcc2382, RCC2385, RCC2421, RCC2527, RCC2535, RCC2553, RCC2570, RCC515, rcc539, rcc752, rcc791, to add}, issn = {0027-8424, 1091-6490}, doi = {10.1073/pnas.2111300118}, url = {http://www.pnas.org/content/118/38/e2111300118}, author = {Six, Christophe and Ratin, Morgane and Marie, Dominique and Corre, Erwan} } @article {dayras_microalgal_2021, title = {Microalgal Diet Influences the Nutritive Quality and Reproductive Investment of the Cyclopoid Copepod Paracyclopina nana}, journal = {Frontiers in Marine Science}, volume = {8}, year = {2021}, pages = {1147}, abstract = {Copepods represent an interesting alternative or a complement live food to brine shrimps and rotifers commonly used in aquaculture. They constitute the natural prey of many fish species and therefore do not require a potential nutritional enrichment. But an optimization of the microalgal diets used to feed copepods is essential to improve their mass culture. This study examined the effects of seven microalgal diets, namely single-species diets of Rhodomonas salina (R), Tisochrysis lutea (T), and Pavlova lutheri (=Diacronema lutheri) (P), two-species diets (R + T, T + P, and R + P), and a three-species diet (R + T + P), on the fatty acid and monosaccharide composition of the cyclopoid copepod Paracyclopina nana as well as its reproductive investment. Experiments were run during 15 days in 10-L beakers; starting with nauplii collected from a large 300-L batch culture. Copepods fatty acid contents were studied, particularly the relative amounts of docosahexaenoic acid (DHA) and eicosa-pentaenoic acid (EPA). The R + T, R, and T diets induced the highest total fatty acid amount in copepods. R + T and R also generated the lowest DHA/EPA ratios in copepods due to high EPA contents. The highest value of total monosaccharides was found in copepods fed with R + T + P. Diets R + T and R induced the greatest prosome volumes and clutch volumes in ovigerous females. Both prosome volume and clutch volume in P. nana ovigerous females were correlated to the individual EPA amount. The results demonstrated that all diets including R. salina enhanced the productivity of P. nana in mass culture, particularly when combined with T. lutea. R. salina, and T. lutea induced complementary fatty acid and monosaccharide profiles, confirming that R + T represents the best microalgae combination for productive culture of P. nana. Conversely, P. lutheri did not enhance the nutritional profile nor the fecundity of P. nana in the culture. This study is the first to demonstrate that R. salina is a suitable microalga for productive mass culture of P. nana for use as live food in aquaculture.}, keywords = {rcc, RCC1349, RCC1537, RCC20}, issn = {2296-7745}, doi = {10.3389/fmars.2021.697561}, url = {https://www.frontiersin.org/article/10.3389/fmars.2021.697561}, author = {Dayras, Paul and Bialais, Capucine and Sadovskaya, Irina and Lee, Min-Chul and Lee, Jae-Seong and Souissi, Sami} } @mastersthesis {busse_mixotrophy_2021, title = {Mixotrophy by Phytoflagellates in the Northern Gulf of Alaska: Impacts of Physico-Chemical Characteristics and Prey Concentration on Feeding by Photosynthetic Nano- and Dinoflagellates}, year = {2021}, school = {Western Washington University}, type = {masters}, keywords = {? No DOI found, RCC3010}, author = {Busse, Hana} } @article {filatov_mode_2021, title = {The mode of speciation during a recent radiation in open-ocean phytoplankton}, journal = {Current Biology}, year = {2021}, month = {oct}, abstract = {Despite the enormous ecological importance of marine phytoplankton, surprisingly little is known about how new phytoplankton species originate and evolve in the open ocean, in the absence of apparent geographic barriers that typically act as isolation mechanisms in speciation. To investigate the mechanism of open-ocean speciation, we combined fossil and climatic records from the late Quaternary with genome-wide evolutionary genetic analyses of speciation in the ubiquitous and abundant pelagic coccolithophore genus Gephyrocapsa (including G. huxleyi, formerly known as Emiliania huxleyi). Based on the analysis of 43 sequenced genomes, we report that the best-fitting scenario for all speciation events analyzed included an extended period of complete isolation followed by recent (Holocene) secondary contact, supporting the role of geographic or oceanographic barriers in population divergence and speciation. Consistent with this, fossil data reveal considerable diachroneity of species first occurrence. The timing of all speciation events coincided with glacial phases of glacial-interglacial cycles, suggesting that stronger isolation between the ocean basins and increased segregation of ecological niches during glaciations are important drivers of speciation in marine phytoplankton. The similarity across multiple speciation events implies the generality of this inferred speciation scenario for marine phytoplankton.}, keywords = {phytoplankton, population genetic modeling, rcc1212, rcc1238, RCC1239, RCC1253, RCC1281, RCC1296, RCC1310, RCC1314, RCC1562, RCC1836, RCC3370, RCC3711, RCC3733, RCC3862, RCC3898, RCC4002, RCC4028, RCC4030, RCC4032, RCC4033, RCC4034, RCC4035, RCC4036, RCC5119, RCC5134, RCC5137, RCC5141, RCC6566, RCC6730, secondary contact, sequence polymorphism, speciation}, issn = {0960-9822}, doi = {10.1016/j.cub.2021.09.073}, url = {https://www.sciencedirect.com/science/article/pii/S0960982221013415}, author = {Filatov, Dmitry A. and Bendif, El Mahdi and Archontikis, Odysseas A. and Hagino, Kyoko and Rickaby, Rosalind E. M.} } @article {wang_moderating_2021, title = {The moderating role of population succession in the adaptive responses of Synechococcus assemblages: evidence from light intensity simulation experiment}, journal = {Photosynthetica}, volume = {59}, number = {4}, year = {2021}, pages = {587{\textendash}599}, abstract = {Synechococcus is one of the most abundant photoautotrophic picoplankton in the marine ecosystem. However, it is not clear how Synechococcus assemblages respond to light intensity variation in a genus group. Here, enriched Synechococcus assemblages from in situ coastal seawater were subjected to light intensity simulation experiments in a range of 9-243 μmol(photon) m{\textendash}2 s{\textendash}1. Characteristics concerning physiology, genomics, and metatranscriptomics were analyzed. Physiologically, the fitting model predicted photosynthesis indications and pigment contents increased with different trends following the light intensity. Genomic sequencing demonstrated that both the phylogenetic and phenotypic compositions of Synechococcus assemblage exhibited population succession. Especially, the proportion of Synechococcus pigment type 2 was changed significantly. In metatranscriptomics, most genes were downregulated in the high-light intensity group, while photosynthesis-related genes were entirely upregulated. The high upregulation of photosynthesis-related genes, such as psbO, psbA, apcB, and cpcB, corresponded to the succession of Synechococcus genotype and was responsible for the physiological shift in response to light intensity.}, issn = {03003604, 15739058}, doi = {10.32615/ps.2021.050}, url = {http://ps.ueb.cas.cz/doi/10.32615/ps.2021.050.html}, author = {Wang, T. and Chen, X. and Li, J.L. and Qin, S. and Cui, Y.L. and Xu, F.} } @article {grebert_molecular_2021, title = {Molecular bases of an alternative dual-enzyme system for light color acclimation of marine \textit{Synechococcus cyanobacteria}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {9}, year = {2021}, pages = {e2019715118}, abstract = {

Marine Synechococcus cyanobacteria owe their ubiquity in part to the wide pigment diversity of their light-harvesting complexes. In open ocean waters, cells predominantly possess sophisticated antennae with rods composed of phycocyanin and two types of phycoerythrins (PEI and PEII). Some strains are specialized for harvesting either green or blue light, while others can dynamically modify their light absorption spectrum to match the dominant ambient color. This process, called type IV chromatic acclimation (CA4), has been linked to the presence of a small genomic island occurring in two configurations (CA4-A and CA4-B). While the CA4-A process has been partially characterized, the CA4-B process has remained an enigma. Here we characterize the function of two members of the phycobilin lyase E/F clan, MpeW and MpeQ, in Synechococcus sp. strain A15-62 and demonstrate their critical role in CA4-B. While MpeW, encoded in the CA4-B island and up-regulated in green light, attaches the green light-absorbing chromophore phycoerythrobilin to cysteine-83 of the PEII α-subunit in green light, MpeQ binds phycoerythrobilin and isomerizes it into the blue light-absorbing phycourobilin at the same site in blue light, reversing the relationship of MpeZ and MpeY in the CA4-A strain RS9916. Our data thus reveal key molecular differences between the two types of chromatic acclimaters, both highly abundant but occupying distinct complementary ecological niches in the ocean. They also support an evolutionary scenario whereby CA4-B island acquisition allowed former blue light specialists to become chromatic acclimaters, while former green light specialists would have acquired this capacity by gaining a CA4-A island.

}, keywords = {RCC2374, to add}, issn = {0027-8424, 1091-6490}, doi = {10.1073/pnas.2019715118}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.2019715118}, author = {Gr{\'e}bert, Th{\'e}ophile and Nguyen, Adam A. and Pokhrel, Suman and Joseph, Kes Lynn and Ratin, Morgane and Dufour, Louison and Chen, Bo and Haney, Allissa M. and Karty, Jonathan A. and Trinidad, Jonathan C. and Garczarek, Laurence and Schluchter, Wendy M. and Kehoe, David M. and Partensky, Fr{\'e}d{\'e}ric} } @article {uwizeye_morphological_2021, title = {Morphological bases of phytoplankton energy management and physiological responses unveiled by 3D subcellular imaging}, journal = {Nature Communications}, volume = {12}, number = {1}, year = {2021}, note = {Number: 1 Publisher: Nature Publishing Group}, month = {feb}, pages = {1{\textendash}12}, abstract = {Phytoplankton account for a large proportion of global primary production and comprise a number of phylogenetically distinct lineages. Here, Uwizeye et al. use FIB-SEM to study ultrastructural plasticity of 7 distinct taxa and describe how subcellular organisation is linked to energy metabolism.}, keywords = {RCC100, RCC4014, RCC827, RCC909}, issn = {2041-1723}, doi = {10.1038/s41467-021-21314-0}, url = {http://www.nature.com/articles/s41467-021-21314-0}, author = {Uwizeye, Clarisse and Decelle, Johan and Jouneau, Pierre-Henri and Flori, Serena and Gallet, Benoit and Keck, Jean-baptiste and Bo, Davide Dal and Moriscot, Christine and Seydoux, Claire and Chevalier, Fabien and Schieber, Nicole L. and Templin, Rachel and Allorent, Guillaume and Courtois, Florence and Curien, Gilles and Schwab, Yannick and Schoehn, Guy and Zeeman, Samuel C. and Falconet, Denis and Finazzi, Giovanni} } @article {decamp_new_2021, title = {A New, Quick, and Simple Protocol to Evaluate Microalgae Polysaccharide Composition}, journal = {Marine Drugs}, volume = {19}, number = {2}, year = {2021}, pages = {101}, abstract = {In this work, a new methodological approach, relying on the high specificity of enzymes in a complex mixture, was developed to estimate the composition of bioactive polysaccharides produced by microalgae, directly in algal cultures. The objective was to set up a protocol to target oligomers commonly known to be associated with exopolysaccharides{\textquoteright} (EPS) nutraceutical and pharmaceutical activities (i.e., rhamnose, fucose, acidic sugars, etc.) without the constraints classically associated with chromatographic methods, while maintaining a resolution sufficiently high to enable their monitoring in the culture system. Determination of the monosaccharide content required the application of acid hydrolysis (2 M trifluoroacetic acid) followed by NaOH (2 M) neutralization. Quantification was then carried out directly on the fresh hydrolysate using enzyme kits corresponding to the main monosaccharides in a pre-determined composition of the polysaccharides under analysis. Initial results showed that the enzymes were not sensitive to the presence of TFA and NaOH, so the methodology could be carried out on fresh hydrolysate. The limits of quantification of the method were estimated as being in the order of the log of nanograms of monosaccharides per well, thus positioning it among the chromatographic methods in terms of analytical performance. A comparative analysis of the results obtained by the enzymatic method with a reference method (high-performance anion-exchange chromatography) confirmed good recovery rates, thus validating the closeness of the protocol. Finally, analyses of raw culture media were carried out and compared to the results obtained in miliQ water; no differences were observed. The new approach is a quick, functional analysis method allowing routine monitoring of the quality of bioactive polysaccharides in algal cultures grown in photobioreactors.}, keywords = {rcc2380, RCC3438}, issn = {1660-3397}, doi = {10.3390/md19020101}, url = {https://www.mdpi.com/1660-3397/19/2/101}, author = {Decamp, Antoine and Michelo, Orane and Rabbat, Christelle and Laroche, C{\'e}line and Grizeau, Dominique and Pruvost, J{\'e}r{\'e}my and Gon{\c c}alves, Olivier} } @article {jimenez_no_2021, title = {No evidence of Phago-mixotropy in Micromonas polaris (Mamiellophyceae), the Dominant Picophytoplankton Species in the Arctic}, journal = {Journal of Phycology}, volume = {57}, number = {2}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/jpy.13125}, pages = {435{\textendash}446}, abstract = {In the Arctic Ocean, the small green alga Micromonas polaris dominates picophytoplankton during the summer months but is also present in winter. It has been previously hypothesized to be phago-mixotrophic (capable of bacteria ingestion) based on laboratory and field experiments. Prey uptake was analyzed in several M. polaris strains isolated from different regions and depths of the Arctic Ocean and in Ochromonas triangulata, a known phago-mixotroph used as a control. Measuring ingestion of either fluorescent beads or fluorescently labeled bacteria by flow cytometry, we found no evidence of phago-mixotrophy in any M. polaris strain while O. triangulata was ingesting both beads and bacteria. In addition, in silico predictions revealed that members of the genus Micromonas lack a genetic signature of phagocytotic capacity.}, keywords = {Arctic, Micromonas, phago-mixotrophy, phytoplankton, rcc, RCC21, RCC2288, RCC2306, RCC4298}, issn = {1529-8817}, doi = {10.1111/jpy.13125}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.13125}, author = {Jimenez, Valeria and Burns, John A. and Le Gall, Florence and Not, Fabrice and Vaulot, Daniel} } @article {harada_novel_2021, title = {A novel characteristic of a phytoplankton as a potential source of straight-chain alkanes}, journal = {Scientific Reports}, volume = {11}, number = {1}, year = {2021}, note = {Bandiera_abtest: a Cc_license_type: cc_by Cg_type: Nature Research Journals Number: 1 Primary_atype: Research Publisher: Nature Publishing Group Subject_term: Biofuels;Biological techniques Subject_term_id: biofuels;biological-techniques}, pages = {14190}, abstract = {Biosynthesis of hydrocarbons is a promising approach for the production of alternative sources of energy because of the emerging need to reduce global consumption of fossil fuels. However, the suitability of biogenic hydrocarbons as fuels is limited because their range of the number of carbon atoms is small, and/or they contain unsaturated carbon bonds. Here, we report that a marine phytoplankton, Dicrateria rotunda, collected from the western Arctic Ocean, can synthesize a series of saturated hydrocarbons (n-alkanes) from C10H22 to C38H78, which are categorized as petrol (C10{\textendash}C15), diesel oils (C16{\textendash}C20), and fuel oils (C21{\textendash}C38). The observation that these n-alkanes were also produced by ten other cultivated strains of Dicrateria collected from the Atlantic and Pacific oceans suggests that this capability is a common characteristic of Dicrateria. We also identified that the total contents of the n-alkanes in the Arctic D. rotunda strain increased under dark and nitrogen-deficient conditions. The unique characteristic of D. rotunda could contribute to the development of a new approach for the biosynthesis of n-alkanes.}, keywords = {RCC3437, RCC4217, RCC4577, RCC4578, RCC5635, RCC5639}, issn = {2045-2322}, doi = {10.1038/s41598-021-93204-w}, url = {http://www.nature.com/articles/s41598-021-93204-w}, author = {Harada, Naomi and Hirose, Yuu and Chihong, Song and Kurita, Hirofumi and Sato, Miyako and Onodera, Jonaotaro and Murata, Kazuyoshi and Itoh, Fumihiro} } @article {yang_opto-electrochemical_2021, title = {Opto-Electrochemical Dissolution Reveals Coccolith Calcium Carbonate Content}, journal = {Angewandte Chemie International Edition}, volume = {60}, number = {38}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.202108435}, pages = {20999{\textendash}21006}, abstract = {Coccoliths are plates of biogenic calcium carbonate secreted by calcifying marine phytoplankton; annually these phytoplankton are responsible for exporting >1 billion tonnes (1015 g) of calcite to the deep ocean. Rapid and reliable methods for assessing the degree of calcification are technically challenging because the coccoliths are micron sized and contain picograms (pg) of calcite. Here we pioneer an opto-eletrochemical acid titration of individual coccoliths which allows 3D reconstruction of each individual coccolith via in situ optical imaging enabling direct inference of the coccolith mass. Coccolith mass ranging from 2 to 400 pg are reported herein, evidencing both inter- and intra-species variation over four different species. We foresee this scientific breakthrough, which is independent of knowledge regarding the species and calibration-free, will allow continuous monitoring and reporting of the degree of coccolith calcification in the changing marine environment.}, keywords = {analytical methods, calcite dissolution, electrochemistry, global carbonate cycle, marine phytoplankton, RCC1130, RCC1198, RCC1216, RCC1314}, issn = {1521-3773}, doi = {10.1002/anie.202108435}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202108435}, author = {Yang, Minjun and Batchelor-McAuley, Christopher and Barton, Samuel and Rickaby, Rosalind E. M. and Bouman, Heather A. and Compton, Richard G.} } @article {russo_production_2021, title = {Production of Omega-3 Oil by Aurantiochytrium mangrovei Using Spent Osmotic Solution from Candied Fruit Industry as Sole Organic Carbon Source}, journal = {Processes}, volume = {9}, number = {10}, year = {2021}, note = {Number: 10 Publisher: Multidisciplinary Digital Publishing Institute}, month = {oct}, pages = {1834}, abstract = {Osmotic dehydration is an important phase in the production of dried products, including most fruits and vegetables, in the food industry. The drying process for candied fruit produces a liquid waste called {\textquotedblleft}spent osmotic solution{\textquotedblright}, which is characterized by a high content of organic compounds, mostly dissolved sugars. The sugar content of this food by-product could be valorized through the growth of biomass with a high added value. In this study, the spent osmotic solution from the candied fruit industry was used as an organic carbon source for the growth and production of docosahexaenoic acid (DHA) in the cultivation of Aurantiochytrium mangrovei RCC893. The carbon content of the standard media was completely replaced by the sugars present in this food by-product. After that, the growth condition of this strain was optimized through response surface methodologies using a central composite design (CCD), and the optimal combination of the spent osmotic solution and nitrogen was established. Moreover, a scale-up trial was performed using the optimal conditions obtained after CCD to evaluate the scalability of the process.}, keywords = {DHA, food waste, Microalgae, PUFA, rcc, RCC893, sustainability}, doi = {10.3390/pr9101834}, url = {https://www.mdpi.com/2227-9717/9/10/1834}, author = {Russo, Giovanni L. and Langellotti, Antonio L. and Blasco, Thierry and Oliviero, Maria and Sacchi, Raffaele and Masi, Paolo} } @article {Farhat2021, title = {Rapid protein evolution, organellar reductions, and invasive intronic elements in the marine aerobic parasite dinoflagellate Amoebophrya spp.}, journal = {BMC Biology}, year = {2021}, note = {Publisher: BMC Biology tex.mendeley-tags: RCC4383,RCC4398}, pages = {1{\textendash}21}, keywords = {Dinoflagellate, genome, Introner elements, Non-canonical introns, parasite, RCC4383, RCC4398}, doi = {10.1186/s12915-020-00927-9}, author = {Farhat, Sarah and Le, Phuong and Kayal, Ehsan and Noel, Benjamin and Bigeard, Estelle and Corre, Erwan and Maumus, Florian and Florent, Isabelle and Alberti, Adriana and Aury, Jean-Marc and Barbeyron, Tristan and Cai, Ruibo and Silva, Corinne Da and Istace, Benjamin and Labadie, Karine and Marie, Dominique and Mercier, Jonathan and Rukwavu, Tsinda and Szymczak, Jeremy and Tonon, Thierry and Alves-de-Souza, Catharina and Rouze, Pierre and de Peer, Yves Van and Wincker, Patrick and Rombauts, Stephane and Porcel, Betina M and Guillou, Laure} } @article {kawachi_rappemonads_2021, title = {Rappemonads are haptophyte phytoplankton}, journal = {Current Biology}, year = {2021}, month = {mar}, abstract = {Rapidly accumulating genetic data from environmental sequencing approaches have revealed an extraordinary level of unsuspected diversity within marine phytoplankton,1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 which is responsible for around 50\% of global net primary production.12,13 However, the phenotypic identity of many of the organisms distinguished by environmental DNA sequences remains unclear. The rappemonads represent a plastid-bearing protistan lineage that to date has only been identified by environmental plastid 16S rRNA sequences.14, 15, 16, 17 The phenotypic identity of this group, which does not confidently cluster in any known algal clades in 16S rRNA phylogenetic reconstructions,15 has remained unknown since the first report of environmental sequences over two decades ago. We show that rappemonads are closely related to a haptophyte microalga, Pavlomulina ranunculiformis gen. nov. et sp. nov., and belong to a new haptophyte class, the Rappephyceae. Organellar phylogenomic analyses provide strong evidence for the inclusion of this lineage within the Haptophyta as a sister group to the Prymnesiophyceae. Members of this new class have a cosmopolitan distribution in coastal and oceanic regions. The relative read abundance of Rappephyceae in a large environmental barcoding dataset was comparable to, or greater than, those of major haptophyte species, such as the bloom-forming Gephyrocapsa huxleyi and Prymnesium parvum, and this result indicates that they likely have a significant impact as primary producers. Detailed characterization of Pavlomulina allowed for reconstruction of the ancient evolutionary history of the Haptophyta, a group that is one of the most important components of extant marine phytoplankton communities.}, keywords = {environmental DNA sequences, morphological evolution, organellar phylogenomics, phytoplankton diversity, RCC3430, transmission electron microscopy}, issn = {0960-9822}, doi = {10.1016/j.cub.2021.03.012}, url = {https://www.sciencedirect.com/science/article/pii/S0960982221003511}, author = {Kawachi, Masanobu and Nakayama, Takuro and Kayama, Motoki and Nomura, Mami and Miyashita, Hideaki and Bojo, Othman and Rhodes, Lesley and Sym, Stuart and Pienaar, Richard N. and Probert, Ian and Inouye, Isao and Kamikawa, Ryoma} } @article {royer_response_2021, title = {Response of dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) cell quotas to oxidative stress in three phytoplankton species}, journal = {Journal of Plankton Research}, volume = {43}, number = {5}, year = {2021}, month = {sep}, pages = {673{\textendash}690}, abstract = {Several phytoplankton species produce the metabolites dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) but their intracellular roles need to be better understood. To improve the understanding of the DMSP antioxidant function suggested by Sunda et al. (2002), we exposed the diatom Skeletonema costatum, the Prymnesiophyceae Phaeocystis globosa and the dinoflagellate Heterocapsa triquetra to experimental treatments known to cause potential oxidative stress (high light intensities (HL); HL with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU); menadione sodium bisulfite (MSB)). DMSP and DMSO concentrations decreased after 6 h in all treatments indicating an interaction with Reactive Oxygen Species (ROS) produced. DMSP and DMSO-to-cell ratios in control conditions were higher for H. triquetra, while being unable to grow under HL. DMSP and DMSO-to-cell carbon were the highest for P. globosa, while the other species had similar values. During long-term treatment, these ratios were not increased in high-light grown cells of P. globosa and S. costatum. Overall, this illustrates that (1) the DMSP- and DMSO-to-cell or carbon seems to be not indicative of the capability of the species to tolerate an oxidative stress, (2) these molecules could react with ROS and lower their cellular concentration, but no clues demonstrated that these molecules are part of the antioxidant response of the cell.}, keywords = {rcc, RCC1719, RCC4800}, issn = {0142-7873}, doi = {10.1093/plankt/fbab052}, url = {https://doi.org/10.1093/plankt/fbab052}, author = {Royer, C and Gypens, N and Cardol, P and Borges, A V and Roberty, S} } @article {langer_role_2021, title = {Role of silicon in the development of complex crystal shapes in coccolithophores}, journal = {New Phytologist}, volume = {231}, number = {5}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/nph.17230}, pages = {1845{\textendash}1857}, abstract = {The development of calcification by the coccolithophores had a profound impact on ocean carbon cycling, but the evolutionary steps leading to the formation of these complex biomineralized structures are not clear. Heterococcoliths consisting of intricately shaped calcite crystals are formed intracellularly by the diploid life cycle phase. Holococcoliths consisting of simple rhombic crystals can be produced by the haploid life cycle stage but are thought to be formed extracellularly, representing an independent evolutionary origin of calcification. We use advanced microscopy techniques to determine the nature of coccolith formation and complex crystal formation in coccolithophore life cycle stages. We find that holococcoliths are formed in intracellular compartments in a similar manner to heterococcoliths. However, we show that silicon is not required for holococcolith formation and that the requirement for silicon in certain coccolithophore species relates specifically to the process of crystal morphogenesis in heterococcoliths. We therefore propose an evolutionary scheme in which the lower complexity holococcoliths represent an ancestral form of calcification in coccolithophores. The subsequent recruitment of a silicon-dependent mechanism for crystal morphogenesis in the diploid life cycle stage led to the emergence of the intricately shaped heterococcoliths, enabling the formation of the elaborate coccospheres that underpin the ecological success of coccolithophores.}, keywords = {biomineralization, Calcification, coccolith, coccolithophore, evolution, rcc, RCC1178, RCC1181, RCC1456, RCC1460, RCC1461, RCC1477, RCC1800, RCC1801, RCC3777, RCC6506, silicon}, issn = {1469-8137}, doi = {10.1111/nph.17230}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.17230}, author = {Langer, Gerald and Taylor, Alison R. and Walker, Charlotte E. and Meyer, Erin M. and Ben Joseph, Oz and Gal, Assaf and Harper, Glenn M. and Probert, Ian and Brownlee, Colin and Wheeler, Glen L.} } @article {castillo_seasonal_2021, title = {Seasonal dynamics of natural Ostreococcus viral infection at the single cell level using VirusFISH}, journal = {Environmental Microbiology}, volume = {n/a}, number = {n/a}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.15504}, abstract = {Ostreococcus is a cosmopolitan marine genus of phytoplankton found in mesotrophic and oligotrophic waters, and the smallest free-living eukaryotes known to date, with a cell diameter close to 1 μm. Ostreococcus has been extensively studied as a model system to investigate viral{\textendash}host dynamics in culture, yet the impact of viruses in naturally occurring populations is largely unknown. Here, we used Virus Fluorescence in situ Hybridization (VirusFISH) to visualize and quantify viral-host dynamics in natural populations of Ostreococcus during a seasonal cycle in the central Cantabrian Sea (Southern Bay of Biscay). Ostreococcus were predominantly found during summer and autumn at surface and 50 m depth, in coastal, mid-shelf and shelf waters, representing up to 21\% of the picoeukaryotic communities. Viral infection was only detected in surface waters, and its impact was variable but highest from May to July and November to December, when up to half of the population was infected. Metatranscriptomic data available from the mid-shelf station unveiled that the Ostreococcus population was dominated by the species O. lucimarinus. This work represents a proof of concept that the VirusFISH technique can be used to quantify the impact of viruses on targeted populations of key microbes from complex natural communities. This article is protected by copyright. All rights reserved.}, keywords = {RCC2590, RCC4221, RCC809}, issn = {1462-2920}, doi = {10.1111/1462-2920.15504}, url = {http://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1462-2920.15504}, author = {Castillo, Yaiza M. and Forn, Irene and Yau, Sheree and Mor{\'a}n, Xos{\'e} Anxelu G. and Alonso-S{\'a}ez, Laura and Arandia-Gorostidi, N{\'e}stor and Vaqu{\'e}, Dolors and Sebasti{\'a}n, Marta} } @article {das_single_2021, title = {Single toxicity of arsenic and combined trace metal exposure to a microalga of ecological and commercial interest: Diacronema lutheri}, journal = {Chemosphere}, year = {2021}, pages = {132949}, abstract = {Eco-toxicological assays with species of economic interest such as Diacronema lutheri are essential for industries that produce aquaculture feed, natural food additives and also in drug developing industries. Our study involved the exposure of a single and combined toxicity of arsenic (As V) to D. lutheri for the entire algal growth phase and highlighted that a combined exposure of As V with other essential (Copper, Cu; Nickel, Ni) and non-essential (Cadmium, Cd; Lead, Pb) trace metals reduced significantly the cell number, chlorophyll a content, and also significantly increased the de-epoxidation ratio (DR) as a stress response when compared to the single toxicity of As V. Arsenic, as one of the ubiquitous trace metal and an active industrial effluent is reported to have an increased bio-concentration factor when in mixture with other trace metals in this study. In the combined exposure, the concentration of total As bio-accumulated by D. lutheri was higher than in the single exposure. Hence, polluted areas with the prevalence of multiple contaminants along with the highly toxic trace metals like As can impose a greater risk to the exposed organisms that may get further bio-magnified in the food chain. Our study highlights the consequences and the response of D. lutheri in terms of contamination from single and multiple trace metals in order to obtain a safer biomass production for the growing need of natural derivatives.}, keywords = {Arsenic, bioaccumulation, Bioconcentration factor, Chlorophyll, de-epoxidation ratio, RCC1537, Trace metals mixture}, issn = {0045-6535}, doi = {10.1016/j.chemosphere.2021.132949}, url = {https://www.sciencedirect.com/science/article/pii/S0045653521034214}, author = {Das, Shagnika and Gevaert, Fran{\c c}ois and Ouddane, Baghdad and Duong, Gwendoline and Souissi, Sami} } @article {graeff_sterol_2021, title = {Sterol Composition of the Peridinioid Dinoflagellate Zooxanthella nutricula, A Symbiont of Polycystine Radiolarians}, journal = {Protist}, volume = {172}, number = {3}, year = {2021}, month = {jul}, pages = {125817}, abstract = {Some dinoflagellates, such as Symbiodinium, are able to form symbiotic relationships with larger marine organisms. An important aspect of dinoflagellate symbiosis involves the exchange of lipids, namely sterols, from the symbiont to the host. Much research has explored the lipid biochemistry of the symbiotic relationship between cnidarians and Symbiodinium dinoflagellates. However, no research has addressed the sterol biochemistry of the symbiosis between radiolarians and dinoflagellates such as Zooxanthella nutricula. To this end, we have provided the first sterol characterization of Z. nutricula isolated from a spumellarian polycystine radiolarian. Fifteen sterols and one steroidal ketone were observed where the major sterol identified was C27 22-dehydrocholesterol, which does not tend to be a dominant sterol among dinoflagellates, including closely related peridinioid species in the genus Heterocapsa. However, C30 dinosterol and dinostanol were major sterols in both Z. nutricula and Heterocapsa spp., thus indicating common sterols between closely related taxa. Major sterols of the distantly related genus Symbiodinium, a symbiont of foraminifera and cnidarians, have included C27 cholesterol and C30 gorgosterol, whereas in Z. nutricula these sterols were minor and absent, respectively. Our results indicate potentially different sterol pools available to cnidarian and radiolarian symbiont hosts during their respective relationships with symbiotic dinoflagellates.}, keywords = {Dinoflagellate, lipid, Peridiniales, Radiolaria, rcc, RCC3387, sterol}, issn = {1434-4610}, doi = {10.1016/j.protis.2021.125817}, url = {https://www.sciencedirect.com/science/article/pii/S1434461021000262}, author = {Graeff, Jori E. and Leblond, Jeffrey D.} } @article {gebuhr_strain-specific_2021, title = {Strain-specific morphological response of the dominant calcifying phytoplankton species Emiliania huxleyi to salinity change}, journal = {PLOS ONE}, volume = {16}, number = {2}, year = {2021}, note = {Publisher: Public Library of Science}, month = {feb}, pages = {e0246745}, abstract = {The future physiology of marine phytoplankton will be impacted by a range of changes in global ocean conditions, including salinity regimes that vary spatially and on a range of short- to geological timescales. Coccolithophores have global ecological and biogeochemical significance as the most important calcifying marine phytoplankton group. Previous research has shown that the morphology of their exoskeletal calcified plates (coccoliths) responds to changing salinity in the most abundant coccolithophore species, Emiliania huxleyi. However, the extent to which these responses may be strain-specific is not well established. Here we investigated the growth response of six strains of E. huxleyi under low (ca. 25) and high (ca. 45) salinity batch culture conditions and found substantial variability in the magnitude and direction of response to salinity change across strains. Growth rates declined under low and high salinity conditions in four of the six strains but increased under both low and high salinity in strain RCC1232 and were higher under low salinity and lower under high salinity in strain PLYB11. When detailed changes in coccolith and coccosphere size were quantified in two of these strains that were isolated from contrasting salinity regimes (coastal Norwegian low salinity of ca. 30 and Mediterranean high salinity of ca. 37), the Norwegian strain showed an average 26\% larger mean coccolith size at high salinities compared to low salinities. In contrast, coccolith size in the Mediterranean strain showed a smaller size trend (11\% increase) but severely impeded coccolith formation in the low salinity treatment. Coccosphere size similarly increased with salinity in the Norwegian strain but this trend was not observed in the Mediterranean strain. Coccolith size changes with salinity compiled for other strains also show variability, strongly suggesting that the effect of salinity change on coccolithophore morphology is likely to be strain specific. We propose that physiological adaptation to local conditions, in particular strategies for plasticity under stress, has an important role in determining ecotype responses to salinity.}, keywords = {Calcification, Carbonates, Ecophysiology, Marine ecology, Marine geology, Morphometry, Paleoclimatology, rcc1210, RCC1232, rcc1824, rcc868, RCC904, salinity}, issn = {1932-6203}, doi = {10.1371/journal.pone.0246745}, url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0246745}, author = {Geb{\"u}hr, Christina and Sheward, Rosie M. and Herrle, Jens O. and Bollmann, J{\"o}rg} } @article {decelle_subcellular_2021, title = {Subcellular architecture and metabolic connection in the planktonic photosymbiosis between Collodaria (radiolarians) and their microalgae}, journal = {bioRxiv}, year = {2021}, note = {Company: Cold Spring Harbor Laboratory Distributor: Cold Spring Harbor Laboratory Label: Cold Spring Harbor Laboratory Section: New Results Type: article}, pages = {2021.03.13.435225}, abstract = {Photosymbiosis is widespread and ecologically important in the oceanic plankton but remains poorly studied. Here, we used multimodal subcellular imaging to investigate the photosymbiosis between colonial Collodaria and their microalga dinoflagellate (Brandtodinium) collected in surface seawaters. We showed that this symbiosis is a very dynamic system whereby symbionts interact with different host cells via extracellular vesicles within the {\textquotedblleft}greenhouse-like{\textquotedblright} colony. 3D electron microscopy revealed that the volume of the photosynthetic apparatus (plastid and pyrenoid) of the microalgae increased in symbiosis compared to free-living while the mitochondria volume was similar. Stable isotope probing coupled with NanoSIMS showed that carbon and nitrogen were assimilated and stored in the symbiotic microalga in starch granules and purine crystals, respectively. Nitrogen was also allocated to the algal nucleus (nucleolus). After 3 hours, low 13C and 15N transfer was detected in the host Golgi. Metal mapping revealed that intracellular iron concentration was similar in free-living and symbiotic microalgae (ca 40 ppm) and two-fold higher in the host, whereas copper concentration increased in symbiotic microalgae (up to 6900 ppm) and was detected in the host cell and extracellular vesicles. Sulfur mapping also pinpointed the importance of this nutrient for the algal metabolism. This study, which revealed subcellular changes of the morphology and nutrient homeostasis in symbiotic microalgae, improves our understanding on the metabolism of this widespread and abundant oceanic symbiosis and paves the way for more studies to investigate the metabolites exchanged.}, doi = {10.1101/2021.03.13.435225}, url = {https://www.biorxiv.org/content/10.1101/2021.03.13.435225v1}, author = {Decelle, Johan and Veronesi, Giulia and LeKieffre, Charlotte and Gallet, Benoit and Chevalier, Fabien and Stryhanyuk, Hryhoriy and Marro, Sophie and Ravanel, St{\'e}phane and Tucoulou, R{\'e}mi and Schieber, Nicole and Finazzi, Giovanni and Schwab, Yannick and Musat, Niculina} } @article {muller_temperature_2021, title = {Temperature Induced Physiological Reaction Norms of the Coccolithophore Gephyrocapsa oceanica and Resulting Coccolith Sr/Ca and Mg/Ca Ratios}, journal = {Frontiers in Earth Science}, volume = {9}, year = {2021}, pages = {273}, abstract = {Coccolithophores are one of the major contributors to the pelagic production of calcium carbonate and their fossilized remains are a key component of the biogeochemical cycles of calcium (Ca), magnesium (Mg), and other divalent cations present in the intracellular precipitated calcitic structures (coccoliths). The geochemical signature of coccoliths (e.g., Sr/Ca and Mg/Ca ratios) is used as paleoproxy to reconstruct past environmental conditions and to understand the underlying physiological precipitation kinetics. Here, we present the elemental fractionation of Sr and Mg in calcite of the coccolithophore Gephyrocapsa oceanica from controlled laboratory experiments applying an extended temperature gradient (12 to 27{\textdegree}C). The physiological reaction norm of G. oceanica, in terms of growth rate, exhibited optimum behavior while the partition coefficient of Sr (DSr) was linearly correlated with temperature and DMg indicated no specific trend. Our results indicate: (1) a presumably secondary physiological control of DSr, and (2) the importance of calibrating coccolithophore-based proxies using experiments that include the full physiological reaction norms (i.e., a possible non-linear response) to environmental drivers (e.g., temperature, salinity, and pH, etc.). The presented results contribute to an improved understanding of the underlying physiological kinetics involved in regulating coccolith elemental fractionation and give additional implications for designing future laboratory experiments to calibrate and apply coccolithophore based paleoproxies on the fossil sediment record.}, keywords = {rcc, RCC1303}, issn = {2296-6463}, doi = {10.3389/feart.2021.582521}, url = {https://www.frontiersin.org/article/10.3389/feart.2021.582521}, author = {M{\"u}ller, Marius N. and Blanco-Ameijeiras, Sonia and Stoll, Heather M. and M{\'e}ndez-Vicente, Ana and Lebrato, Mario} } @article {labban_temperature_2021, title = {Temperature Responses of Heterotrophic Bacteria in Co-culture With a Red Sea Synechococcus Strain}, journal = {Frontiers in Microbiology}, volume = {12}, year = {2021}, pages = {612732}, abstract = {Interactions between autotrophic and heterotrophic bacteria are fundamental for marine biogeochemical cycling. How global warming will affect the dynamics of these essential microbial players is not fully understood. The aims of this study were to identify the major groups of heterotrophic bacteria present in a Synechococcus culture originally isolated from the Red Sea and assess their joint responses to experimental warming within the metabolic ecology framework. A co-culture of Synechococcus sp. RS9907 and their associated heterotrophic bacteria, after determining their taxonomic affiliation by 16S rRNA gene sequencing, was acclimated and maintained in the lab at different temperatures (24{\textendash}34{\textdegree}C). The abundance and cellular properties of Synechococcus and the three dominant heterotrophic bacterial groups (pertaining to the genera Paracoccus, Marinobacter, and Muricauda) were monitored by flow cytometry. The activation energy of Synechococcus, which grew at 0.94{\textendash}1.38 d{\textendash}1, was very similar (0.34 {\textpm} 0.02 eV) to the value hypothesized by the metabolic theory of ecology (MTE) for autotrophs (0.32 eV), while the values of the three heterotrophic bacteria ranged from 0.16 to 1.15 eV and were negatively correlated with their corresponding specific growth rates (2.38{\textendash}24.4 d{\textendash}1). The corresponding carrying capacities did not always follow the inverse relationship with temperature predicted by MTE, nor did we observe a consistent response of bacterial cell size and temperature. Our results show that the responses to future ocean warming of autotrophic and heterotrophic bacteria in microbial consortia might not be well described by theoretical universal rules.}, keywords = {rcc, RCC546}, issn = {1664-302X}, doi = {10.3389/fmicb.2021.612732}, url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8141594/}, author = {Labban, Abbrar and Palacio, Antonio S. and Garc{\'\i}a, Francisca C. and Hadaidi, Ghaida and Ansari, Mohd I. and L{\'o}pez-Urrutia, {\'A}ngel and Alonso-S{\'a}ez, Laura and Hong, Pei-Ying and Mor{\'a}n, Xos{\'e} Anxelu G.} } @booklet {roquis_tropical_2021, title = {The tropical coral Pocillopora acuta displays an unusual chromatin structure and shows histone H3 clipping plasticity upon bleaching}, number = {6:195}, year = {2021}, note = {Type: article}, month = {jul}, publisher = {Wellcome Open Research}, abstract = {

Background: Pocillopora acuta is a hermatypic coral with strong ecological importance. Anthropogenic disturbances and global warming are major threats that can induce coral bleaching, the disruption of the mutualistic symbiosis between the coral host and its endosymbiotic algae. Previous works have shown that somaclonal colonies display different levels of survival depending on the environmental conditions they previously faced. Epigenetic mechanisms are good candidates to explain this phenomenon. However, almost no work had been published on the P. acuta epigenome, especially on histone modifications. In this study, we aim at providing the first insight into chromatin structure of this species. Methods: We aligned the amino acid sequence of P. acuta core histones with histone sequences from various phyla. We developed a centri-filtration on sucrose gradient to separate chromatin from the host and the symbiont. The presence of histone H3 protein and specific histone modifications were then detected by western blot performed on histone extraction done from bleached and healthy corals. Finally, micrococcal nuclease (MNase) digestions were undertaken to study nucleosomal organization. Results: The centri-filtration enabled coral chromatin isolation with less than 2\% of contamination by endosymbiont material. Histone sequences alignments with other species show that P. acuta displays on average \textasciitilde90\% of sequence similarities with mice and \textasciitilde96\% with other corals. H3 detection by western blot showed that H3 is clipped in healthy corals while it appeared to be intact in bleached corals. MNase treatment failed to provide the usual mononucleosomal digestion, a feature shared with some cnidarian, but not all; suggesting an unusual chromatin structure. Conclusions: These results provide a first insight into the chromatin, nucleosome and histone structure of P. acuta . The unusual patterns highlighted in this study and partly shared with other cnidarian will need to be further studied to better understand its role in corals.

}, keywords = {chromatin structure, Histone H3 clipping, invertebrate epigenetics, Pocillopora acuta, Pocillopora damicornis, rcc, RCC4017}, doi = {10.12688/wellcomeopenres.17058.1}, url = {https://wellcomeopenresearch.org/articles/6-195}, author = {Roquis, David and Cosseau, C{\'e}line and Raffalli, Kelly Brener and Romans, Pascal and Masanet, Patrick and Mitta, Guillaume and Grunau, Christoph and Vidal-Dupiol, Jeremie} } @article {bachy_viruses_2021, title = {Viruses infecting a warm water picoeukaryote shed light on spatial co-occurrence dynamics of marine viruses and their hosts}, journal = {The ISME Journal}, year = {2021}, note = {Publisher: Nature Publishing Group}, month = {may}, pages = {1{\textendash}19}, abstract = {The marine picoeukaryote Bathycoccus prasinos has been considered a cosmopolitan alga, although recent studies indicate two ecotypes exist, Clade BI (B. prasinos) and Clade BII. Viruses that infect Bathycoccus Clade BI are known (BpVs), but not that infect BII. We isolated three dsDNA prasinoviruses from the Sargasso Sea against Clade BII isolate RCC716. The BII-Vs do not infect BI, and two (BII-V2 and BII-V3) have larger genomes (\textasciitilde210 kb) than BI-Viruses and BII-V1. BII-Vs share \textasciitilde90\% of their proteins, and between 65\% to 83\% of their proteins with sequenced BpVs. Phylogenomic reconstructions and PolB analyses establish close-relatedness of BII-V2 and BII-V3, yet BII-V2 has 10-fold higher infectivity and induces greater mortality on host isolate RCC716. BII-V1 is more distant, has a shorter latent period, and infects both available BII isolates, RCC716 and RCC715, while BII-V2 and BII-V3 do not exhibit productive infection of the latter in our experiments. Global metagenome analyses show Clade BI and BII algal relative abundances correlate positively with their respective viruses. The distributions delineate BI/BpVs as occupying lower temperature mesotrophic and coastal systems, whereas BII/BII-Vs occupy warmer temperature, higher salinity ecosystems. Accordingly, with molecular diagnostic support, we name Clade BII Bathycoccus calidus sp. nov. and propose that molecular diversity within this new species likely connects to the differentiated host-virus dynamics observed in our time course experiments. Overall, the tightly linked biogeography of Bathycoccus host and virus clades observed herein supports species-level host specificity, with strain-level variations in infection parameters.}, keywords = {RCC715, RCC716}, issn = {1751-7370}, doi = {10.1038/s41396-021-00989-9}, url = {https://www.nature.com/articles/s41396-021-00989-9}, author = {Bachy, Charles and Yung, Charmaine C. M. and Needham, David M. and Gazit{\'u}a, Maria Consuelo and Roux, Simon and Limardo, Alexander J. and Choi, Chang Jae and Jorgens, Danielle M. and Sullivan, Matthew B. and Worden, Alexandra Z.} } @article {barbeyron_zobellia_2021, title = {Zobellia roscoffensis sp. nov. and Zobellia nedashkovskayae sp. nov., two flavobacteria from the epiphytic microbiota of the brown alga Ascophyllum nodosum, and emended description of the genus Zobellia}, journal = {International Journal of Systematic and Evolutionary Microbiology}, volume = {71}, number = {8}, year = {2021}, abstract = {Four marine bacterial strains were isolated from a thallus of the brown alga Ascophyllum nodosum collected in Roscoff, France. Cells were Gram-s- tain--negative, strictly aerobic, non-f-lagellated, gliding, rod--shaped and grew optimally at 25{\textendash}30 {\textdegree}C, at pH 7{\textendash}8 and with 2{\textendash}4 \% NaCl. Phylogenetic analyses of their 16S rRNA gene sequences showed that the bacteria were affiliated to the genus Zobellia (family Flavobacteriaceae, phylum Bacteroidetes). The four strains exhibited 97.8{\textendash}100 \% 16S rRNA gene sequence similarity values among themselves, 97.9{\textendash}99.1 \% to the type strains of Zobellia amurskyensis KMM 3526T and Zobellia laminariae KMM 3676T, and less than 99 \% to other species of the genus Zobellia. The DNA G+C content of the four strains ranged from 36.7 to 37.7 mol\%. Average nucleotide identity and digital DNA{\textendash}DNA hybridization calculations between the new strains and other members of the genus Zobellia resulted in values of 76.4{\textendash}88.9 \% and below 38.5 \%, respectively. Phenotypic, phylogenetic and genomic analyses showed that the four strains are distinct from species of the genus Zobellia with validly published names. They represent two novel species of the genus Zobellia, for which the names Zobellia roscoffensis sp. nov. and Zobellia nedashkovskayae sp. nov. are proposed with Asnod1--F08T (RCC6906T=KMM 6823T=CIP 111902T) and Asnod2--B07--BT (RCC6908T=KMM 6825T=CIP 111904T), respectively, as the type strains.}, keywords = {RCC6906, RCC6907, RCC6908, RCC6909}, issn = {1466-5026, 1466-5034}, doi = {10.1099/ijsem.0.004913}, url = {https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.004913}, author = {Barbeyron, Tristan and Thi{\'e}baud, Manon and Le Duff, Nolwen and Martin, Marjolaine and Corre, Erwan and Tanguy, Gwenn and Vandenbol, Micheline and Thomas, Fran{\c c}ois} } @article {Bestion2020, title = {Abrupt declines in marine phytoplankton production driven by warming and biodiversity loss in a microcosm experiment}, journal = {Ecology Letters}, volume = {23}, number = {3}, year = {2020}, note = {tex.mendeley-tags: RCC1303,RCC1512,RCC4221,RCC623,RCC626,RCC652,RCC80,RCC834}, month = {mar}, pages = {457{\textendash}466}, abstract = {Rising sea surface temperatures are expected to lead to the loss of phytoplankton biodiversity. However, we currently understand very little about the interactions between warming, loss of phytoplankton diversity and its impact on the oceans{\textquoteright} primary production. We experimentally manipulated the species richness of marine phytoplankton communities under a range of warming scenarios, and found that ecosystem production declined more abruptly with species loss in communities exposed to higher temperatures. Species contributing positively to ecosystem production in the warmed treatments were those that had the highest optimal temperatures for photosynthesis, implying that the synergistic impacts of warming and biodiversity loss on ecosystem functioning were mediated by thermal trait variability. As species were lost from the communities, the probability of taxa remaining that could tolerate warming diminished, resulting in abrupt declines in ecosystem production. Our results highlight the potential for synergistic effects of warming and biodiversity loss on marine primary production.}, keywords = {biodiversity, biodiversity loss, climate change, ecosystem functioning, phytoplankton, RCC1303, rcc1512, RCC4221, RCC623, RCC626, RCC652, RCC80, RCC834, thermal per-}, issn = {1461-023X}, doi = {10.1111/ele.13444}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13444}, author = {Bestion, Elvire and Barton, Samuel and Garc{\'\i}a, Francisca C. and Warfield, Ruth and Yvon-Durocher, Gabriel}, editor = {Hillebrand, Helmut} } @article {Nissimov2020, title = {Aquatic virus culture collection: an absent (but necessary) safety net for environmental microbiologists}, journal = {Applied Phycology}, volume = {00}, number = {00}, year = {2020}, note = {Publisher: Taylor \& Francis}, pages = {1{\textendash}15}, keywords = {algae, Aquatic viruses, bacteria, biological preservation, community resource, culture collection, genetic and metabolic diversity}, issn = {2638-8081}, doi = {10.1080/26388081.2020.1770123}, url = {https://doi.org/10.1080/26388081.2020.1770123 https://www.tandfonline.com/doi/full/10.1080/26388081.2020.1770123}, author = {Nissimov, Jozef I and Campbell, Christine N and Probert, Ian and Wilson, William H} } @article {Pan2020, title = {Assessments of first feeding protocols on the larviculture of California grunion Leuresthes tenuis (Osteichthyes: Atherinopsidae)}, journal = {Aquaculture Research}, volume = {51}, number = {7}, year = {2020}, note = {Publisher: Blackwell Publishing Ltd tex.mendeley-tags: RCC350}, month = {jul}, pages = {3054{\textendash}3058}, keywords = {California grunion, Copepod, larval rearing, live feed, quiescent egg, RCC350}, issn = {13652109}, doi = {10.1111/are.14637}, url = {https://onlinelibrary.wiley.com/doi/10.1111/are.14637}, author = {Pan, Yen Ju and D{\'e}pos{\'e}, Emilien and Souissi, Anissa and H{\'e}nard, St{\'e}phane and Schaadt, Mike and Mastro, Ed and Souissi, Sami} } @article {Androuin2020, title = {Better off alone? New insights in the symbiotic relationship between the flatworm Symsagittifera roscoffensis and the microalgae Tetraselmis convolutae}, journal = {Symbiosis}, number = {Keebles 1910}, year = {2020}, note = {tex.mendeley-tags: RCC1563}, month = {jun}, abstract = {The acoel flatworm Symsagittifera roscoffensis lives in obligatory symbiosis with the microalgal chlorophyte Tetraselmis convolutae. Although this interaction has been studied for more than a century, little is known on the potential reciprocal benefits of both partners, a subject that is still controversial. In order to provide new insights into this question, we have compared the photophysiology of the free-living microalgae to the symbiotic form in the flatworm, both acclimated at different light irradiances. Photosynthesis {\textendash} Irradiance curves showed that the free-living T. convolutae had greater photosynthetic performance (i.e., oxygen production rates, ability to harvest light) than their symbiotic form, regardless of the light acclimation. However, they were affected by photoinhibition under high irradiances, which did not happen for the symbiotic form. The resistance of symbiotic microalgae to photoinhibition were corroborated by pigment analyses, which evidenced the induction of photoprotective mechanisms such as xanthophyll cycle as well as lutein and β-carotene accumulation. These processes were induced even under low light acclimation and exacerbated upon high light acclimation, suggesting a global stress situation for the symbiotic microalgae. We hypothesize that the internal conditions in the sub-epidermal zone of the flatworm (e.g., osmotic and pH), as well as the phototaxis toward high light imposed by the worm in its environment, would be major reasons for this chronic stress situation. Overall, our study suggests that the relationship between S. roscoffensis and T. convolutae may be a farming strategy in favor of the flatworm rather than a symbiosis with mutual benefits.}, keywords = {Animal-plant, Photobiology, RCC1563, symbiosis, Symsagittifera roscoffensis, Tetraselmis convolutae}, issn = {0334-5114}, doi = {10.1007/s13199-020-00691-y}, url = {http://link.springer.com/10.1007/s13199-020-00691-y}, author = {Androuin, Thibault and Six, Christophe and Bordeyne, Fran{\c c}ois and de Bettignies, Florian and Noisette, Fanny and Davoult, Dominique} } @article {Liao2020, title = {C41 methyl and C42 ethyl alkenones are biomarkers for Group II Isochrysidales}, journal = {Organic Geochemistry}, volume = {147}, year = {2020}, note = {Publisher: Elsevier Ltd tex.mendeley-tags: RCC1207,RCC1346,RCC3483}, month = {sep}, pages = {104081}, abstract = {Alkenones are polyunsaturated long-chain methyl or ethyl ketones produced by species in the Isochrysidales, an order of haptophyte algae. Based on phylogenetic data, members of the Isochrysidales have been classified into three groups with each group showing significant differences in alkenone profiles and preferred growth environments. Common carbon chain lengths of alkenones range from 37 to 40. Extended C41 methyl (C41Me) and C42 ethyl (C42Et) alkenones have been reported in hypersaline lakes in China (Lake Alahake and Lake Balikun), Canada (Lake Snakehole) and marine sediments (e.g., \~95 Ma in Blake-Bahama Basin). It is unclear, however, if these extended alkenones are produced by one or more groups of Isochrysidales. Here, we systematically examined alkenones from cultures of Group II (Isochrysis nuda, Isochrysis litoralis, Ruttnera lamellosa, Isochrysis galbana and Tisochrysis lutea) and Group III (Emiliania huxleyi and Gephyrocapsa oceanica) Isochrysidales and environmental samples of Group I Isochysidales. C41Me and C42Et alkenones were found in all Group II species with Isochrysis nuda producing the highest percentages, but not in alkenones produced by Group I nor Group III Isochrysidales. Our results indicate that extended C41Me and C42Et alkenones are specific biomarkers for Group II Isochrysidales. We also report the first temperature calibrations of alkenones for Isochrysis nuda and Isochrysis litoralis using culture experiments, and find temperatures inferred from extended alkenones in Balikun and Alahake surface sediments match warm-season temperatures based on Isochrysis nuda calibrations, which is further corroborated by genomic data indicating the dominance of Isochrysis nuda Isochrysidales.}, keywords = {18S rDNA, Biomarkers, C41 and C42 alkenones, culture, evolution, Isochrysidales, RCC1207, RCC1346, RCC3483}, issn = {01466380}, doi = {10.1016/j.orggeochem.2020.104081}, author = {Liao, Sian and Yao, Yuan and Wang, Li and Wang, Karen J. and Amaral-Zettler, Linda and Longo, William M. and Huang, Yongsong} } @article {Benner2019, title = {Capacity of the common Arctic picoeukaryote Micromonas to adapt to a warming ocean}, journal = {Limnology and Oceanography Letters}, volume = {5}, number = {2}, year = {2020}, note = {tex.mendeley-tags: RCC807}, month = {apr}, pages = {221{\textendash}227}, keywords = {RCC807}, issn = {2378-2242}, doi = {10.1002/lol2.10133}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lol2.10133}, author = {Benner, Ina and Irwin, Andrew J and Finkel, Zoe V} } @article {Palacio2020, title = {Changes in population age-structure obscure the temperature-size rule in marine cyanobacteria}, journal = {Frontiers in Microbiology}, volume = {11}, year = {2020}, note = {Publisher: Frontiers Media S.A. tex.mendeley-tags: RCC2382,RCC3377}, month = {aug}, pages = {2059}, abstract = {The temperature-size Rule (TSR) states that there is a negative relationship between ambient temperature and body size. This rule has been independently evaluated for different phases of the life cycle in multicellular eukaryotes, but mostly for the average population in unicellular organisms. We acclimated two model marine cyanobacterial strains (Prochlorococcus marinus MIT9301 and Synechococcus sp. RS9907) to a gradient of temperatures and measured the changes in population age-structure and cell size along their division cycle. Both strains displayed temperature-dependent diel changes in cell size, and as a result, the relationship between temperature and average cell size varied along the day. We computed the mean cell size of new-born cells in order to test the prediction of the TSR on a single-growth stage. Our work reconciles previous inconsistent results when testing the TSR on unicellular organisms, and shows that when a single-growth stage is considered the predicted negative response to temperature is revealed.}, keywords = {cell cycle, Cell Division, cell size, Prochlorococcus, rcc2382, RCC3377, Synechococcus, temperature, temperature-size rule}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.02059}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2020.02059/full}, author = {Palacio, Antonio S. and Cabello, Ana Mar{\'\i}a and Garc{\'\i}a, Francisca C. and Labban, Abbrar and Mor{\'a}n, Xos{\'e} Anxelu G. and Garczarek, Laurence and Alonso-S{\'a}ez, Laura and L{\'o}pez-Urrutia, {\'A}ngel} } @article {Mucko2020, title = {Characterization of a lipid-producing thermotolerant marine photosynthetic pico-alga in the genus Picochlorum (Trebouxiophyceae)}, journal = {European Journal of Phycology}, volume = {00}, number = {00}, year = {2020}, note = {Publisher: Taylor \& Francis tex.mendeley-tags: RCC1034,RCC13,RCC14,RCC289,RCC475,RCC6905,RCC846,RCC9,RCC945}, month = {aug}, pages = {1{\textendash}16}, keywords = {morphology, photosynthetic picoeukaryotes, phylogeny, physiology, Picochlorum, RCC1034, RCC13, RCC14, rcc289, RCC475, RCC6905, RCC846, RCC9, RCC945}, issn = {0967-0262}, doi = {10.1080/09670262.2020.1757763}, url = {https://doi.org/10.1080/09670262.2020.1757763 https://www.tandfonline.com/doi/full/10.1080/09670262.2020.1757763}, author = {Mucko, Maja and Padis{\'a}k, Judit and Gligora Udovi{\v c}, Marija and P{\'a}lmai, Tam{\'a}s and Novak, Tihana and Medi{\'c}, Nikola and Ga{\v s}parovi{\'c}, Bla{\v z}enka and Peharec {\v S}tefani{\'c}, Petra and Orli{\'c}, Sandi and Ljube{\v s}i{\'c}, Zrinka} } @article {Carrigee2020, title = {CpeY is a phycoerythrobilin lyase for cysteine 82 of the phycoerythrin I α-subunit in marine Synechococcus}, journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics}, year = {2020}, note = {Publisher: Elsevier B.V tex.mendeley-tags: RCC555}, month = {apr}, pages = {148215}, keywords = {rcc555}, issn = {00052728}, doi = {10.1016/j.bbabio.2020.148215}, url = {https://doi.org/10.1016/j.bbamem.2019.183135 https://linkinghub.elsevier.com/retrieve/pii/S0005272820300657}, author = {Carrigee, Lyndsay A. and Mahmoud, Rania M. and Sanfilippo, Joseph E. and Frick, Jacob P. and Strnat, Johann A. and Karty, Jonathan A. and Chen, Bo and Kehoe, David M. and Schluchter, Wendy M.} } @article {Cai2020, title = {Cryptic species in the parasitic Amoebophrya species complex revealed by a polyphasic approach}, journal = {Scientific Reports}, volume = {10}, number = {1}, year = {2020}, note = {Publisher: Springer US tex.mendeley-tags: RCC1627,RCC1720,RCC3018,RCC3043,RCC3044,RCC3047,RCC3048,RCC3049,RCC3145,RCC3278,RCC3596,RCC4381,RCC4382,RCC4383,RCC4384,RCC4385,RCC4386,RCC4387,RCC4388,RCC4389,RCC4390,RCC4391,RCC4392,RCC4393,RCC4394,RCC4395,RCC4396,RCC4397,RCC4398,RCC4399,RCC4400,RCC4401,RCC4402,RCC4403,RCC4404,RCC4405,RCC4406,RCC4407,RCC4408,RCC4409,RCC4410,RCC4411,RCC4412,RCC4413,RCC4414,RCC4415,RCC4416,RCC4711,RCC4712,RCC4713,RCC4715,RCC4716,RCC4722,RCC4723,RCC4726,RCC4728,RCC4729,RCC4732,RCC4733,RCC4734,RCC5984,RCC5985,RCC5986,RCC5987,RCC5988,RCC5989,RCC5990,RCC5991,RCC5992,RCC5993,RCC5994,RCC5995,RCC5997,RCC5998,RCC5999,RCC6000,RCC6001,RCC6002,RCC6003,RCC6004,RCC6005,RCC6006,RCC6007,RCC6008,RCC6009,RCC6010,RCC6079,RCC6080,RCC6081,RCC6082,RCC6083,RCC6084,RCC6085,RCC6087,RCC6088,RCC6094,RCC6096,RCC6100,RCC6101,RCC6102,RCC6103,RCC6104,RCC6105,RCC6106,RCC6107,RCC6108,RCC6109,RCC6110,RCC6111,RCC6112,RCC6113,RCC6115,RCC6116,RCC6117,RCC6118,RCC6119,RCC6120,RCC6121}, month = {dec}, pages = {2531}, keywords = {RCC1627, RCC1720, RCC3018, RCC3043, RCC3044, RCC3047, RCC3048, RCC3049, RCC3145, RCC3278, RCC3596, RCC4381, RCC4382, RCC4383, RCC4384, RCC4385, RCC4386, RCC4387, RCC4388, RCC4389, RCC4390, RCC4391, RCC4392, RCC4393, RCC4394, RCC4395, RCC4396, RCC4397, RCC4398, RCC4399, RCC4400, RCC4401, RCC4402, RCC4403, RCC4404, RCC4405, RCC4406, RCC4407, RCC4408, RCC4409, RCC4410, RCC4411, RCC4412, RCC4413, RCC4414, RCC4415, RCC4416, RCC4711, RCC4712, RCC4713, RCC4715, RCC4716, RCC4722, RCC4723, RCC4726, RCC4728, RCC4729, RCC4732, RCC4733, RCC4734, RCC5984, RCC5985, RCC5986, RCC5987, RCC5988, RCC5989, RCC5990, RCC5991, RCC5992, RCC5993, RCC5994, RCC5995, RCC5997, RCC5998, RCC5999, RCC6000, RCC6001, RCC6002, RCC6003, RCC6004, RCC6005, RCC6006, RCC6007, RCC6008, RCC6009, RCC6010, RCC6079, RCC6080, RCC6081, RCC6082, RCC6083, RCC6084, RCC6085, RCC6087, RCC6088, RCC6094, RCC6096, RCC6100, RCC6101, RCC6102, RCC6103, RCC6104, RCC6105, RCC6106, RCC6107, RCC6108, RCC6109, RCC6110, RCC6111, RCC6112, RCC6113, RCC6115, RCC6116, RCC6117, RCC6118, RCC6119, RCC6120, RCC6121}, issn = {2045-2322}, doi = {10.1038/s41598-020-59524-z}, url = {http://dx.doi.org/10.1038/s41598-020-59524-z http://www.nature.com/articles/s41598-020-59524-z}, author = {Cai, Ruibo and Kayal, Ehsan and Alves-de-Souza, Catharina and Bigeard, Estelle and Corre, Erwan and Jeanthon, Christian and Marie, Dominique and Porcel, Betina M and Siano, Raffaele and Szymczak, Jeremy and Wolf, Matthias and Guillou, Laure} } @article {Ribeiro2020, title = {Culturable diversity of Arctic phytoplankton during pack ice melting}, journal = {Elementa: Science of the Anthropocene}, volume = {8}, number = {1}, year = {2020}, note = {tex.mendeley-tags: RCC5197,RCC5198,RCC5199,RCC5200,RCC5201,RCC5202,RCC5203,RCC5204,RCC5205,RCC5206,RCC5207,RCC5208,RCC5209,RCC5210,RCC5211,RCC5212,RCC5213,RCC5214,RCC5215,RCC5216,RCC5217,RCC5218,RCC5219,RCC5220,RCC5221,RCC5222,RCC5223,RCC5224,RCC5225,RCC5226,RCC5227,RCC5228,RCC5229,RCC5230,RCC5231,RCC5232,RCC5233,RCC5234,RCC5235,RCC5236,RCC5237,RCC5238,RCC5239,RCC5240,RCC5241,RCC5242,RCC5243,RCC5244,RCC5245,RCC5246,RCC5247,RCC5248,RCC5249,RCC5250,RCC5251,RCC5252,RCC5253,RCC5254,RCC5255,RCC5256,RCC5257,RCC5258,RCC5259,RCC5260,RCC5261,RCC5262,RCC5263,RCC5264,RCC5265,RCC5266,RCC5267,RCC5268,RCC5269,RCC5270,RCC5271,RCC5272,RCC5273,RCC5274,RCC5275,RCC5276,RCC5277,RCC5278,RCC5279,RCC5280,RCC5281,RCC5282,RCC5283,RCC5284,RCC5285,RCC5286,RCC5287,RCC5288,RCC5289,RCC5290,RCC5291,RCC5292,RCC5293,RCC5294,RCC5295,RCC5296,RCC5297,RCC5298,RCC5299,RCC5300,RCC5301,RCC5302,RCC5303,RCC5304,RCC5305,RCC5306,RCC5307,RCC5308,RCC5309,RCC5310,RCC5311,RCC5312,RCC5313,RCC5314,RCC5315,RCC5316,RCC5317,RCC5318,RCC5319,RCC5320,RCC5321,RCC5322,RCC5323,RCC5324,RCC5325,RCC5326,RCC5327,RCC5328,RCC5329,RCC5330,RCC5331,RCC5332,RCC5333,RCC5334,RCC5335,RCC5336,RCC5337,RCC5338,RCC5339,RCC5340,RCC5341,RCC5342,RCC5343,RCC5344,RCC5345,RCC5346,RCC5347,RCC5348,RCC5349,RCC5350,RCC5351,RCC5352,RCC5353,RCC5354,RCC5355,RCC5356,RCC5357,RCC5358,RCC5359,RCC5360,RCC5361,RCC5362,RCC5363,RCC5364,RCC5365,RCC5366,RCC5367,RCC5368,RCC5369,RCC5370,RCC5371,RCC5372,RCC5373,RCC5374,RCC5375,RCC5376,RCC5377,RCC5378,RCC5379,RCC5380,RCC5381,RCC5382,RCC5383,RCC5384,RCC5385,RCC5386,RCC5387,RCC5388,RCC5389,RCC5390,RCC5391,RCC5392,RCC5393,RCC5394,RCC5395,RCC5396,RCC5397,RCC5398,RCC5399,RCC5400,RCC5401,RCC5402,RCC5403,RCC5404,RCC5405,RCC5406,RCC5407,RCC5408,RCC5409,RCC5410,RCC5411,RCC5412,RCC5413,RCC5414,RCC5415,RCC5416,RCC5417,RCC5418,RCC5419,RCC5420,RCC5421,RCC5422,RCC5423,RCC5424,RCC5425,RCC5426,RCC5427,RCC5428,RCC5429,RCC5430,RCC5431,RCC5432,RCC5433,RCC5434,RCC5435,RCC5436,RCC5437,RCC5438,RCC5439,RCC5440,RCC5441,RCC5442,RCC5443,RCC5444,RCC5445,RCC5446,RCC5447,RCC5448,RCC5449,RCC5450,RCC5451,RCC5452,RCC5453,RCC5454,RCC5455,RCC5456,RCC5457,RCC5458,RCC5459,RCC5460,RCC5461,RCC5462,RCC5463,RCC5464,RCC5465,RCC5466,RCC5467,RCC5468,RCC5469,RCC5470,RCC5471,RCC5472,RCC5473,RCC5474,RCC5475,RCC5476,RCC5477,RCC5478,RCC5479,RCC5480,RCC5481,RCC5482,RCC5483,RCC5484,RCC5485,RCC5486,RCC5487,RCC5488,RCC5489,RCC5490,RCC5491,RCC5492,RCC5493,RCC5494,RCC5495,RCC5496,RCC5497,RCC5498,RCC5499,RCC5500,RCC5501,RCC5502,RCC5503,RCC5504,RCC5505,RCC5506,RCC5507,RCC5508,RCC5509,RCC5510,RCC5511,RCC5512,RCC5513,RCC5514,RCC5515,RCC5516,RCC5517,RCC5518,RCC5519,RCC5520,RCC5521,RCC5522,RCC5523,RCC5524,RCC5525,RCC5526,RCC5527,RCC5528,RCC5529,RCC5530,RCC5531,RCC5532,RCC5533,RCC5534,RCC5535,RCC5536,RCC5537,RCC5538,RCC5539,RCC5540,RCC5541,RCC5542,RCC5543,RCC5544,RCC5545,RCC5546,RCC5547,RCC5548,RCC5549,RCC5550,RCC5551,RCC5552,RCC5553,RCC5554,RCC5555,RCC5556,RCC5557,RCC5558,RCC5559,RCC5560,RCC5561,RCC5562,RCC5563,RCC5564,RCC5565,RCC5566,RCC5567,RCC5568,RCC5569,RCC5570,RCC5571,RCC5572,RCC5573,RCC5574,RCC5575,RCC5576,RCC5577,RCC5578,RCC5579,RCC5580,RCC5581,RCC5582,RCC5583,RCC5584,RCC5585,RCC5586,RCC5587,RCC5588,RCC5589,RCC5590,RCC5591,RCC5592,RCC5593,RCC5594,RCC5595,RCC5596,RCC5597,RCC5598,RCC5599,RCC5600,RCC5601,RCC5602,RCC5603,RCC5604,RCC5605,RCC5606,RCC5607,RCC5608,RCC5609,RCC5610,RCC5611,RCC5612}, month = {feb}, pages = {6}, abstract = {Massive phytoplankton blooms develop at the Arctic ice edge, sometimes extending far under the pack ice. An extensive culturing effort was conducted before and during a phytoplankton bloom in Baffin Bay between April and July 2016. Different isolation strategies were applied, including flow cytometry cell sorting, manual single cell pipetting and serial dilution. Although all three techniques yielded the most common organisms, each technique retrieved specific taxa, highlighting the importance of using several methods to maximize the number and diversity of isolated strains. More than 1,000 cultures were obtained, characterized by 18S rRNA sequencing and optical microscopy and de-replicated to a subset of 276 strains presented in this work. Strains grouped into 57 genotypes defined by 100\% 18S rRNA sequence similarity. These genotypes spread across five divisions: Heterokontophyta, Chlorophyta, Cryptophyta, Haptophyta and Dinophyta. Diatoms were the most abundant group (193 strains), mostly represented by the genera Chaetoceros and Attheya. The genera Rhodomonas and Pyramimonas were the most abundant non-diatom nanoplankton strains, while Micromonas polaris dominated the picoplankton. Diversity at the class level was higher during the peak of the bloom. Potentially new species were isolated, in particular within the genera Navicula, Nitzschia, Coscinodiscus, Thalassiosira, Pyramimonas, Mantoniella and Isochrysis.}, keywords = {RCC5197, RCC5198, RCC5199, RCC5200, RCC5201, RCC5202, RCC5203, RCC5204, RCC5205, RCC5206, RCC5207, RCC5208, RCC5209, RCC5210, RCC5211, RCC5212, RCC5213, RCC5214, RCC5215, RCC5216, RCC5217, RCC5218, RCC5219, RCC5220, RCC5221, RCC5222, RCC5223, RCC5224, RCC5225, RCC5226, RCC5227, RCC5228, RCC5229, RCC5230, RCC5231, RCC5232, RCC5233, RCC5234, RCC5235, RCC5236, RCC5237, RCC5238, RCC5239, RCC5240, RCC5241, RCC5242, RCC5243, RCC5244, RCC5245, RCC5246, RCC5247, RCC5248, RCC5249, RCC5250, RCC5251, RCC5252, RCC5253, RCC5254, RCC5255, RCC5256, RCC5257, RCC5258, RCC5259, RCC5260, RCC5261, RCC5262, RCC5263, RCC5264, RCC5265, RCC5266, RCC5267, RCC5268, RCC5269, RCC5270, RCC5271, RCC5272, RCC5273, RCC5274, RCC5275, RCC5276, RCC5277, RCC5278, RCC5279, RCC5280, RCC5281, RCC5282, RCC5283, RCC5284, RCC5285, RCC5286, RCC5287, RCC5288, RCC5289, RCC5290, RCC5291, RCC5292, RCC5293, RCC5294, RCC5295, RCC5296, RCC5297, RCC5298, RCC5299, RCC5300, RCC5301, RCC5302, RCC5303, RCC5304, RCC5305, RCC5306, RCC5307, RCC5308, RCC5309, RCC5310, RCC5311, RCC5312, RCC5313, RCC5314, RCC5315, RCC5316, RCC5317, RCC5318, RCC5319, RCC5320, RCC5321, RCC5322, RCC5323, RCC5324, RCC5325, RCC5326, RCC5327, RCC5328, RCC5329, RCC5330, RCC5331, RCC5332, RCC5333, RCC5334, RCC5335, RCC5336, RCC5337, RCC5338, RCC5339, RCC5340, RCC5341, RCC5342, RCC5343, RCC5344, RCC5345, RCC5346, RCC5347, RCC5348, RCC5349, RCC5350, RCC5351, RCC5352, RCC5353, RCC5354, RCC5355, RCC5356, RCC5357, RCC5358, RCC5359, RCC5360, RCC5361, RCC5362, RCC5363, RCC5364, RCC5365, RCC5366, RCC5367, RCC5368, RCC5369, RCC5370, RCC5371, RCC5372, RCC5373, RCC5374, RCC5375, RCC5376, RCC5377, RCC5378, RCC5379, RCC5380, RCC5381, RCC5382, RCC5383, RCC5384, RCC5385, RCC5386, RCC5387, RCC5388, RCC5389, RCC5390, RCC5391, RCC5392, RCC5393, RCC5394, RCC5395, RCC5396, RCC5397, RCC5398, RCC5399, RCC5400, RCC5401, RCC5402, RCC5403, RCC5404, RCC5405, RCC5406, RCC5407, RCC5408, RCC5409, RCC5410, RCC5411, RCC5412, RCC5413, RCC5414, RCC5415, RCC5416, RCC5417, RCC5418, RCC5419, RCC5420, RCC5421, RCC5422, RCC5423, RCC5424, RCC5425, RCC5426, RCC5427, RCC5428, RCC5429, RCC5430, RCC5431, RCC5432, RCC5433, RCC5434, RCC5435, RCC5436, RCC5437, RCC5438, RCC5439, RCC5440, RCC5441, RCC5442, RCC5443, RCC5444, RCC5445, RCC5446, RCC5447, RCC5448, RCC5449, RCC5450, RCC5451, RCC5452, RCC5453, RCC5454, RCC5455, RCC5456, RCC5457, RCC5458, RCC5459, RCC5460, RCC5461, RCC5462, RCC5463, RCC5464, RCC5465, RCC5466, RCC5467, RCC5468, RCC5469, RCC5470, RCC5471, RCC5472, RCC5473, RCC5474, RCC5475, RCC5476, RCC5477, RCC5478, RCC5479, RCC5480, RCC5481, RCC5482, RCC5483, RCC5484, RCC5485, RCC5486, RCC5487, RCC5488, RCC5489, RCC5490, RCC5491, RCC5492, RCC5493, RCC5494, RCC5495, RCC5496, RCC5497, RCC5498, RCC5499, RCC5500, RCC5501, RCC5502, RCC5503, RCC5504, RCC5505, RCC5506, RCC5507, RCC5508, RCC5509, RCC5510, RCC5511, RCC5512, RCC5513, RCC5514, RCC5515, RCC5516, RCC5517, RCC5518, RCC5519, RCC5520, RCC5521, RCC5522, RCC5523, RCC5524, RCC5525, RCC5526, RCC5527, RCC5528, RCC5529, RCC5530, RCC5531, RCC5532, RCC5533, RCC5534, RCC5535, RCC5536, RCC5537, RCC5538, RCC5539, RCC5540, RCC5541, RCC5542, RCC5543, RCC5544, RCC5545, RCC5546, RCC5547, RCC5548, RCC5549, RCC5550, RCC5551, RCC5552, RCC5553, RCC5554, RCC5555, RCC5556, RCC5557, RCC5558, RCC5559, RCC5560, RCC5561, RCC5562, RCC5563, RCC5564, RCC5565, RCC5566, RCC5567, RCC5568, RCC5569, RCC5570, RCC5571, RCC5572, RCC5573, RCC5574, RCC5575, RCC5576, RCC5577, RCC5578, RCC5579, RCC5580, RCC5581, RCC5582, RCC5583, RCC5584, RCC5585, RCC5586, RCC5587, RCC5588, RCC5589, RCC5590, RCC5591, RCC5592, RCC5593, RCC5594, RCC5595, RCC5596, RCC5597, RCC5598, RCC5599, RCC5600, RCC5601, RCC5602, RCC5603, RCC5604, RCC5605, RCC5606, RCC5607, RCC5608, RCC5609, RCC5610, RCC5611, RCC5612}, issn = {2325-1026}, doi = {10.1525/elementa.401}, url = {https://www.biorxiv.org/content/10.1101/642264v1 https://www.elementascience.org/article/10.1525/elementa.401/}, author = {Ribeiro, Catherine G{\'e}rikas and dos Santos, Adriana Lopes and Gourvil, Priscillia and Le Gall, Florence and Marie, Dominique and Tragin, Margot and Probert, Ian and Vaulot, Daniel} } @article {Avrahami2020, title = {Detection of phagotrophy in the marine phytoplankton group of the coccolithophores (calcihaptophycidae, haptophyta) during Nutrient-replete and Phosphate-limited growth}, journal = {Journal of Phycology}, year = {2020}, note = {tex.mendeley-tags: RCC1130,RCC1131,RCC1178,RCC1216,RCC1217,RCC3779}, month = {apr}, pages = {jpy.12997}, abstract = {Mixotrophic algae that combine photoautotrophy with phagotrophy in a single cell are prevalent in marine ecosystems. Here, we assessed the ability of food ingestion in coccolithophores, an important group of calcifying haptophytes inhabiting the oceans. We tested four species from different coccolithophore lineages (Emiliania huxleyi, Calcidiscus leptoporus, Coccolithus braarudii, and Calyptrosphaera sphaeroidea). For both E. huxleyi and C. leptoporus we included different life phases (haploid and diploid). For C. braarudii we only tested diploid heterococcolithophore cells, while for C. sphaeroidea we only tested haploid holococcolithophore cells. Phagotrophy was assessed using fluorescently labeled bacteria (FLB) as model prey item, under nutrient-replete and phosphate-limited conditions. We detected by microscopy ingestion of FLB by all species, except the diploid C. braarudii strain. However, a previous study detected ingestion by haploid cells of C. braarudii. These overall results indicate that mixotrophy and the ability to ingest prey is widespread in coccolithophores. Yet, in all tested species the ingestion of FLB was low ({\textexclamdown}1\% of the population contained prey at all time points over 2 days), namely for E. huxleyi and the diploid cells from C. leptoporus where detection of ingestion was sporadic. Moreover, no clear differences were detected between life phases in E. huxleyi and C. leptoporus under equal circumstances, or between replete and limited growth conditions.}, keywords = {bacterivory, coccolithophores, life cycle, mixotrophy, phytoplankton, RCC1130, RCC1131, RCC1178, RCC1216, rcc1217, RCC3779}, issn = {0022-3646}, doi = {10.1111/jpy.12997}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.12997}, author = {Avrahami, Yoav and Frada, Miguel J.}, editor = {Mock, T.} } @article {Connell2020, title = {Diel oscillations in the feeding activity of heterotrophic and mixotrophic nanoplankton in the North Pacific Subtropical Gyre}, journal = {Aquatic Microbial Ecology}, volume = {85}, year = {2020}, note = {Publisher: Inter-Research Science Center tex.mendeley-tags: RCC80}, month = {dec}, pages = {167{\textendash}181}, abstract = {Daily oscillations in photosynthetically active radiation strongly influence the timing of metabolic processes in picocyanobacteria, but it is less clear how the light-dark cycle affects the activities of their consumers. We investigated the relationship between marine picocyanobacteria and nanoplanktonic consumers throughout the diel cycle to determine whether heterotrophic and mixotrophic protists (algae with phagotrophic ability) display significant periodicity in grazing pressure. Carbon biomass of Prochlorococcus and Synechococcus was estimated continuously from abundances and cell size measurements made by flow cytometry. Picocyanobacterial dynamics were then compared to nanoplankton abundances and ingestion of fluorescently labeled bacteria measured every 4 h during a 4 d survey in the North Pacific Subtropical Gyre. Grazing of the labeled bacteria by heterotrophic nanoplankton was significantly greater at night than during the day. The grazing activity of mixotrophic nanoplankton showed no diel periodicity, suggesting that they may feed continuously, albeit at lower rates than heterotrophic nanoplankton, to alleviate nutrient limitation in this oligotrophic environment. Diel changes in Prochlorococcus biomass indicated that they could support substantial growth of nanoplankton if those grazers are the main source of picocyanobacterial mortality, and that grazers may contribute to temporally stable abundances of picocyanobacteria.}, keywords = {bacterivory, diel cycles, mixotrophy, nanoplankton grazing, picocyanobacteria, RCC80}, issn = {0948-3055}, doi = {10.3354/ame01950}, url = {http://dx.doi.org/10.3354/ame01950 https://www.int-res.com/abstracts/ame/v85/p167-181/}, author = {Connell, PE and Ribalet, F and Armbrust, EV and White, A and Caron, DA} } @article {Wittek2020, title = {Dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) cell quotas variations arising from sea ice shifts of salinity and temperature in the Prymnesiophyceae Phaeocystis antarctica}, journal = {Environmental Chemistry}, year = {2020}, note = {tex.mendeley-tags: RCC4023}, abstract = {Environmental context. Dimethylsulfoniopropionate and dimethylsulfoxide could have a climatic influence especially in the polar areas. We investigate the effect of sea ice salinity and temperature on the production of these two sulfur metabolites by a polar microalga, and suggest their potential roles of osmoregulator and cryoprotectant. These results bring new information about the sulfur cycle in sea ice that is useful for climate models.. The Southern Ocean, which includes the seasonal ice zone (SIZ), is a source of large sea-air fluxes of dimethylsulfide (DMS), a climate active gas involved in Earth cooling processes. In this area, the prymnesiophyte Phaeocystis antarctica (P. antarctica) is one of the main producers of dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO), two metabolites that are precursors of DMS. These algae are also present in sea ice and contribute substantially to the high DMSP and DMSO concentrations observed in this habitat. DMSP and DMSO production in sea ice by P. antarctica is proposed to be promoted by its ability to live in extreme environmental conditions. We designed cell culture experiments to test that hypothesis, focusing on the impact of shifts of temperature and salinity on the DMSP and DMSO cell quotas. Our experiments show an increase in DMSP and DMSO cell quotas following shifts in salinity (34 to 75, at 4 {\textdegree}C), which suggests a potential osmoregulator function for both DMSP and DMSO. Stronger salinity shifts (up to 100) directly impact cell growth and induce a crash of the cultures. Combining the salinity (34 to 75) and temperature (4 {\textdegree}C to {\textendash}2.3 {\textdegree}C) shifts induces higher increases of DMSP and DMSO cell quotas that also suggests an implication of both metabolites in a cryoprotectant system. Experimental cell quotas (including diatom Fragilariopsis cylindrus quotas from a previous study) are then used to reconstruct DMSP and DMSO profiles in sea ice based on the biomass and taxonomy. Finally, the complexity of the transposition of rates obtained in the experimental domain to the real world is discussed.}, keywords = {RCC4023}, doi = {10.1071/EN19302}, url = {https://doi.org/10.1071/EN19302}, author = {Wittek, Boris and Carnat, Gauthier and Delille, Bruno and Tison, Jean-Louis and Gypens, Nathalie} } @article {Altenburger2020, title = {Dimorphism in cryptophytes{\textemdash}The case of Teleaulax amphioxeia / Plagioselmis prolonga and its ecological implications}, journal = {Science Advances}, volume = {6}, number = {37}, year = {2020}, note = {tex.mendeley-tags: RCC5152}, month = {sep}, pages = {eabb1611}, abstract = {Growing evidence suggests that sexual reproduction might be common in unicellular organisms, but observations are sparse. Limited knowledge of sexual reproduction constrains understanding of protist ecology. Although Teleaulax amphioxeia and Plagioselmis prolonga are common marine cryptophytes worldwide, and are also important plastid donors for some kleptoplastic ciliates and dinoflagellates, the ecology and development of these protists are poorly known. We demonstrate that P. prolonga is the haploid form of the diploid T. amphioxeia and describe the seasonal dynamics of these two life stages. The diploid T. amphioxeia dominates during periods of high dissolved inorganic nitrogen (DIN) and low irradiance, temperature, and grazing (winter and early spring), whereas the haploid P. prolonga becomes more abundant during the summer, when DIN is low and irradiance, temperature, and grazing are high. Dimorphic sexual life cycles might explain the success of this species by fostering high genetic diversity and enabling endurance in adverse conditions.}, keywords = {RCC5152}, issn = {2375-2548}, doi = {10.1126/sciadv.abb1611}, url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.abb1611}, author = {Altenburger, A and Blossom, H E and Garcia-Cuetos, L. and Jakobsen, H H and Carstensen, J and Lundholm, N. and Hansen, P. J. and Moestrup, {\O}. and Haraguchi, L.} } @article {Kayal2020, title = {Dinoflagellate host chloroplasts and mitochondria remain functional during amoebophrya infection}, journal = {Frontiers in Microbiology}, volume = {11}, number = {December}, year = {2020}, note = {tex.mendeley-tags: RCC1627,RCC4398}, month = {dec}, pages = {1{\textendash}11}, abstract = {Dinoflagellates are major components of phytoplankton that play critical roles in many microbial food webs, many of them being hosts of countless intracellular parasites. The phototrophic dinoflagellate Scrippsiella acuminata (Dinophyceae) can be infected by the microeukaryotic parasitoids Amoebophrya spp. (Syndiniales), some of which primarily target and digest the host nucleus. Early digestion of the nucleus at the beginning of the infection is expected to greatly impact the host metabolism, inducing the knockout of the organellar machineries that highly depend upon nuclear gene expression, such as the mitochondrial OXPHOS pathway and the plastid photosynthetic carbon fixation. However, previous studies have reported that chloroplasts remain functional in swimming host cells infected by Amoebophrya . We report here a multi-approach monitoring study of S. acuminata organelles over a complete infection cycle by nucleus-targeting Amoebophrya sp. strain A120. Our results show sustained and efficient photosystem II activity as a hallmark of functional chloroplast throughout the infection period despite the complete digestion of the host nucleus. We also report the importance played by light on parasite production, i.e., the amount of host biomass converted to parasite infective propagules. Using a differential gene expression analysis, we observed an apparent increase of all 3 mitochondrial and 9 out of the 11 plastidial genes involved in the electron transport chains (ETC) of the respiration pathways during the first stages of the infection. The longer resilience of organellar genes compared to those encoded by the nucleus suggests that both mitochondria and chloroplasts remain functional throughout most of the infection. This extended organelle functionality, along with higher parasite production under light conditions, suggests that host bioenergetic organelles likely benefit the parasite Amoebophrya sp. A120 and improve its fitness during the intracellular infective stage.}, keywords = {amoebophrya, chloroplast, Dinoflagellate, frontiers in microbiology, frontiersin, kleptoplast, marine plankton, org, organelles, parasitism, RCC1627, RCC4398, www}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.600823}, url = {https://www.frontiersin.org/articles/10.3389/fmicb.2020.600823/full}, author = {Kayal, Ehsan and Alves-de-Souza, Catharina and Farhat, Sarah and Velo-Suarez, Lourdes and Monjol, Joanne and Szymczak, Jeremy and Bigeard, Estelle and Marie, Dominique and Noel, Benjamin and Porcel, Betina M and Corre, Erwan and Six, Christophe and Guillou, Laure} } @article {Fitzsimons2020, title = {Dissolved organic phosphorus uptake by marine phytoplankton is enhanced by the presence of dissolved organic nitrogen}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {530-531}, number = {July}, year = {2020}, note = {Publisher: Elsevier tex.mendeley-tags: RC2563,RCC2565}, month = {sep}, pages = {151434}, abstract = {Organic nutrients can constitute the major fractions (up to 70\%) of aquatic nitrogen (N) and phosphorus (P), but their cycling is poorly understood relative to the inorganic pools. Some phytoplankton species access P from the dissolved organic phosphorus (DOP) pool through expression of alkaline phosphatase (AP), which hydrolyses orthophosphate from organic molecules, and is thought to occur either at low concentrations of dissolved inorganic P (DIP), or elevated ratios of dissolved inorganic N (DIN) to DIP. Three algal strains native to the North-East Atlantic Ocean (coccolithophore, dinoflagellate and diatom species) were grown under representative, temperate conditions, and the dissolved N and P components amended to include dissolved organic N (DON) and DOP. The activity of AP was measured to determine the rate of DOP uptake by each algal species. The addition of DON and DOP enhanced the growth of the algal species, regardless of DIN and DIP concentrations. In cultures where the total concentrations and absolute N: P ratio was unchanged but the N pool included both DON and DIN, an increase in alkaline phosphatase activity (APA) was measured. This suggested that the presence of DON triggered the selective uptake of DOP. The uptake of organic P was confirmed by detection of adenosine in DOP-amended culture media, indicating that P had been cleaved from ADP and ATP added to the media as DOP, and cellular P concentration in these cultures exceeded the calculated concentration based on uptake of DIP only. Our data demonstrates that organic nutrients can enhance and sustain marine algal productivity. The findings have implications for marine ecosystem function and health, since climate change scenarios predict variable riverine inputs to coastal areas, altered N: P ratios, and changes in the inorganic to organic balance of the nutrient pools.}, keywords = {Alkaline phosphatase, COASTAL WATERS, Dissolved organic nitrogen, Dissolved organic phosphorus, Marine algae, P-limitation, RCC2563, RCC2565}, issn = {00220981}, doi = {10.1016/j.jembe.2020.151434}, url = {https://doi.org/10.1016/j.jembe.2020.151434 https://linkinghub.elsevier.com/retrieve/pii/S0022098119304666}, author = {Fitzsimons, Mark F. and Probert, Ian and Gaillard, Fanny and Rees, Andrew P.} } @article {Arsenieff2020, title = {Diversity and dynamics of relevant nanoplanktonic diatoms in the Western English Channel}, journal = {The ISME Journal}, year = {2020}, note = {Publisher: Springer US tex.mendeley-tags: RCC4657,RCC4658,RCC4659,RCC4660,RCC4661,RCC4662,RCC4663,RCC4664,RCC4665,RCC4666,RCC5154,RCC5839,RCC5840,RCC5841,RCC5842,RCC5843,RCC5844,RCC5845,RCC5846,RCC5847,RCC5848,RCC5849,RCC5850,RCC5851,RCC5852,RCC5853,RCC5854,RCC5855,RCC5856,RCC5857,RCC5859,RCC5860,RCC5861,RCC5862,RCC5863,RCC5864,RCC5865,RCC5866,RCC5867,RCC5868,RCC5869,RCC5870,RCC5871,RCC5872,RCC5873,RCC5875,RCC5876,RCC5877,RCC5878,RCC5879,RCC5880,RCC5881,RCC5882,RCC5883,RCC5884,RCC5885,RCC5886,RCC5887,RCC5921}, month = {apr}, keywords = {RCC4657, RCC4658, RCC4659, RCC4660, RCC4661, RCC4662, RCC4663, RCC4664, RCC4665, RCC4666, RCC5154, RCC5839, RCC5840, RCC5841, RCC5842, RCC5843, RCC5844, RCC5845, RCC5846, RCC5847, RCC5848, RCC5849, RCC5850, RCC5851, RCC5852, RCC5853, RCC5854, RCC5855, RCC5856, RCC5857, RCC5859, RCC5860, RCC5861, RCC5862, RCC5863, RCC5864, RCC5865, RCC5866, RCC5867, RCC5868, RCC5869, RCC5870, RCC5871, RCC5872, RCC5873, RCC5875, RCC5876, RCC5877, RCC5878, RCC5879, RCC5880, RCC5881, RCC5882, RCC5883, RCC5884, RCC5885, RCC5886, RCC5887, RCC5921}, issn = {1751-7362}, doi = {10.1038/s41396-020-0659-6}, url = {http://dx.doi.org/10.1038/s41396-020-0659-6 http://www.nature.com/articles/s41396-020-0659-6}, author = {Arsenieff, Laure and Le Gall, Florence and Rigaut-jalabert, Fabienne and Mah{\'e}, Fr{\'e}d{\'e}ric and Sarno, Diana and Gouhier, L{\'e}na and Baudoux, Anne-claire and Simon, Nathalie} } @article {Kuwata2020, title = {Draft whole-genome sequence of triparma laevis f. inornata (parmales, bolidophyceae), isolated from the oyashio region, western north pacific ocean}, journal = {Microbiology Resource Announcements}, volume = {9}, number = {33}, year = {2020}, note = {ISBN: 9781493991730 tex.mendeley-tags: RCC4655}, month = {aug}, pages = {13{\textendash}14}, abstract = {We present the first draft whole-genome sequence for the Parmales (Bolidophyceae, Heterokonta), a picoplanktonic sister group of diatoms, using a Triparma laevis f. inornata strain that was isolated from the Oyashio region in the western North Pacific Ocean.}, keywords = {RCC4655}, issn = {2576-098X}, doi = {10.1128/MRA.00367-20}, url = {https://mra.asm.org/content/9/33/e00367-20}, author = {Kuwata, Akira and Saitoh, Kenji and Nakamura, Yoji and Ichinomiya, Mutsuo and Sato, Naoki}, editor = {Stajich, Jason E.} } @article {Coelho2020, title = {Ectocarpus: an evo-devo model for the brown algae}, journal = {EvoDevo}, volume = {11}, number = {1}, year = {2020}, note = {ISBN: 1322702000164 Publisher: BioMed Central}, month = {dec}, pages = {19}, keywords = {Brown algae, complex, Complex multicellularity, cycle, Ectocarpus, ectocarpus is a genus, filamentous, Gametophyte, life-cycle, Marine, multicellu-, multicellularity, natural habitat and life, of small, Phaeoviruses, Sex determination, Sporophyte}, issn = {2041-9139}, doi = {10.1186/s13227-020-00164-9}, url = {https://doi.org/10.1186/s13227-020-00164-9 https://evodevojournal.biomedcentral.com/articles/10.1186/s13227-020-00164-9}, author = {Coelho, Susana M and Peters, Akira F and M{\"u}ller, Dieter and Cock, J Mark} } @article {Thorel2020, title = {Effect of 10 UV filters on the brine shrimp Artemia salina and themarinemicroalga Tetraselmis sp.}, journal = {Toxics}, volume = {8}, number = {2}, year = {2020}, note = {Publisher: MDPI AG tex.mendeley-tags: RCC500}, month = {jun}, pages = {29}, abstract = {The presence of pharmaceutical and personal care product (PPCP) residues in the aquatic environment is an emerging issue due to their uncontrolled release through gray water, and accumulation in the environment that may affect living organisms, ecosystems and public health. The aim of this study is to assess the toxicity of benzophenone-3 (BP-3), bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), butyl methoxydibenzoylmethane (BM), methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT), 2-ethylhexyl salicylate (ES), diethylaminohydroxybenzoyl hexyl benzoate (DHHB), diethylhexyl butamido triazone (DBT), ethylhexyl triazone (ET), homosalate (HS) and octocrylene (OC) on marine organisms from two major trophic levels, including autotrophs (Tetraselmis sp.) and heterotrophs (Artemia salina). In general, results showed that both HS and OC were the most toxic UV filters for our tested species, followed by a significant effect of BM on Artemia salina due to BM-but only at high concentrations (1 mg/L). ES, BP3 and DHHB affected the metabolic activity of the microalgae at 100 ??g/L. BEMT, DBT, ET, MBBT had no effect on the tested organisms, even at high concentrations (2 mg/L). OC toxicity represents a risk for those species, since concentrations used in this study are 15-90 times greater than those reported in occurrence studies for aquatic environments. For the first time in the literature, we report HS toxicity on a microalgae species at concentrations complementing those found in aquatic environments. These preliminary results could represent a risk in the future if concentrations of OC and HS continue to increase.}, keywords = {Artemia salina, marine environment, Marine microalgae, RCC500, Toxicity tests, UV-filters}, issn = {23056304}, doi = {10.3390/TOXICS8020029}, url = {www.mdpi.com/journal/toxics}, author = {Thorel, Evane and Clergeaud, Fanny and Jaugeon, Lucie and Rodrigues, Alice M.S. and Lucas, Julie and Stien, Didier and Lebaron, Philippe} } @article {Klintzsch2020, title = {Effects of temperature and light on methane production of widespread marine phytoplankton}, journal = {Journal of Geophysical Research: Biogeosciences}, volume = {125}, number = {9}, year = {2020}, note = {Publisher: American Geophysical Union (AGU) tex.mendeley-tags: RCC1216}, month = {sep}, keywords = {RCC1216}, issn = {2169-8953}, doi = {10.1029/2020jg005793}, url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020JG005793 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JG005793 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JG005793}, author = {Klintzsch, T. and Langer, G. and Wieland, A. and Geisinger, H. and Lenhart, K. and Nehrke, G. and Keppler, F.} } @article {Morais2020, title = {Electrochemical genosensor for the detection of Alexandrium minutum dinoflagellates}, journal = {Talanta}, year = {2020}, note = {Publisher: Elsevier B.V. tex.mendeley-tags: RCC3029}, pages = {121416}, keywords = {RCC3029}, issn = {00399140}, doi = {10.1016/j.talanta.2020.121416}, url = {https://doi.org/10.1016/j.talanta.2020.121416 https://linkinghub.elsevier.com/retrieve/pii/S0039914020307074}, author = {Morais, Stephanie L. and Barros, Piedade and Santos, Marlene and Delerue-Matos, Cristina and Gomes, Andreia C. and F{\'a}tima Barroso, M.} } @article {Dore2020, title = {Evolutionary mechanisms of long-term genome diversification associated with niche partitioning in marine picocyanobacteria}, journal = {Frontiers in Microbiology}, volume = {11}, number = {September}, year = {2020}, note = {tex.mendeley-tags: RCC1084,RCC1085,RCC1086,RCC1087,RCC156,RCC158,RCC162,RCC2033,RCC2035,RCC2319,RCC2366,RCC2368,RCC2369,RCC2374,RCC2376,RCC2378,RCC2379,RCC2380,RCC2381,RCC2382,RCC2383,RCC2385,RCC2433,RCC2436,RCC2438,RCC2527,RCC2528,RCC2533,RCC2534,RCC2535,RCC2553,RCC2554,RCC2555,RCC2556,RCC2571,RCC2673,RCC278,RCC296,RCC307,RCC328,RCC3377,RCC407,RCC515,RCC539,RCC555,RCC556,RCC752,RCC753,RCC791}, month = {sep}, pages = {1{\textendash}23}, keywords = {amino-acid substitutions, comparative genomics, evolution, genomic islands, marine cyanobacteria, niche adaptation, Prochlorococcus, rcc1084, RCC1085, RCC1086, RCC1087, RCC156, RCC158, rcc162, RCC2033, RCC2035, RCC2319, RCC2366, RCC2368, RCC2369, RCC2374, RCC2376, RCC2378, RCC2379, rcc2380, RCC2381, rcc2382, RCC2383, RCC2385, RCC2433, RCC2436, RCC2438, RCC2527, RCC2528, RCC2533, RCC2534, RCC2535, RCC2553, RCC2554, RCC2555, RCC2556, RCC2571, RCC2673, RCC278, rcc296, RCC307, RCC328, RCC3377, RCC407, RCC515, rcc539, rcc555, RCC556, rcc752, RCC753, rcc791, Synechococcus}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.567431}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2020.567431/full}, author = {Dor{\'e}, Hugo and Farrant, Gregory K. and Guyet, Ulysse and Haguait, Julie and Humily, Florian and Ratin, Morgane and Pitt, Frances D. and Ostrowski, Martin and Six, Christophe and Brillet-Gu{\'e}guen, Loraine and Hoebeke, Mark and Bisch, Antoine and Le Corguill{\'e}, Gildas and Corre, Erwan and Labadie, Karine and Aury, Jean-Marc and Wincker, Patrick and Choi, Dong Han and Noh, Jae Hoon and Eveillard, Damien and Scanlan, David J. and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence} } @article {Barton2020, title = {Evolutionary temperature compensation of carbon fixation in marine phytoplankton}, journal = {Ecology Letters}, year = {2020}, note = {tex.mendeley-tags: RCC1303,RCC1512,RCC1773,RCC4221,RCC623,RCC626,RCC652,RCC80,RCC834}, month = {feb}, pages = {ele.13469}, abstract = {The efficiency of carbon sequestration by the biological pump could decline in the coming decades because respiration tends to increase more with temperature than photosynthesis. Despite these differences in the short-term temperature sensitivities of photosynthesis and respiration, it remains unknown whether the long-term impacts of global warming on metabolic rates of phytoplankton can be modulated by evolutionary adaptation. We found that respiration was consistently more temperature dependent than photosynthesis across 18 diverse marine phytoplankton, resulting in universal declines in the rate of carbon fixation with short-term increases in temperature. Long-term experimental evolution under high temperature reversed the short-term stimulation of metabolic rates, resulting in increased rates of carbon fixation. Our findings suggest that thermal adaptation may therefore have an ameliorating impact on the efficiency of phytoplankton as primary mediators of the biological carbon pump.}, keywords = {climate change, evolutionary ecology, metabolism, phytoplankton physiology, RCC1303, rcc1512, RCC1773, RCC4221, RCC623, RCC626, RCC652, RCC80, RCC834, thermal performance curves}, issn = {1461-023X}, doi = {10.1111/ele.13469}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13469}, author = {Barton, Samuel and Jenkins, James and Buckling, Angus and Schaum, C.-Elisa and Smirnoff, Nicholas and Raven, John A. and Yvon-Durocher, Gabriel}, editor = {Ezenwa, Vanessa} } @article {Henry2020, title = {Formation and fate of oil-related aggregates (ORAs) in seawater at different temperatures}, journal = {Marine Pollution Bulletin}, volume = {159}, number = {July}, year = {2020}, note = {Publisher: Elsevier tex.mendeley-tags: RCC4289}, month = {oct}, pages = {111483}, abstract = {In this study, the formation and fate of oil-related aggregates (ORAs) from chemically dispersed oil in seawater (SW) were investigated at different temperatures (5 {\textdegree}C, 13 {\textdegree}C, 20 {\textdegree}C). Experiments in natural SW alone, and in SW amended with typical marine snow constituents (phytoplankton and mineral particles), showed that the presence of algae stimulated the formation of large ORAs, while high SW temperature resulted in faster aggregate formation. The ORAs formed at 5 {\textdegree}C and 13 {\textdegree}C required mineral particles for sinking, while the aggregates also sank in the absence of mineral particles at 20{\textdegree}. Early in the experimental periods, oil compound accumulation in ORAs was faster than biodegradation, particularly in aggregates with algae, followed by rapid biodegradation. High abundances of bacteria associated with hydrocarbon biodegradation were determined in the ORAs, together with algae-associated bacteria, while clustering analyses showed separation between bacterial communities in experiments with oil alone and oil with algae/mineral particles.}, keywords = {Aggregation, biodegradation, Dispersed oil, Marine snow, Microbial communities, RCC4289, Sinking}, issn = {0025326X}, doi = {10.1016/j.marpolbul.2020.111483}, url = {https://doi.org/10.1016/j.marpolbul.2020.111483 https://linkinghub.elsevier.com/retrieve/pii/S0025326X20306019}, author = {Henry, Ingrid A. and Netzer, Roman and Davies, Emlyn J. and Brakstad, Odd Gunnar} } @article {Hackl2019, title = {Four high-quality draft genome assemblies of the marine heterotrophic nanoflagellate Cafeteria roenbergensis}, journal = {Scientific Data}, volume = {7}, number = {1}, year = {2020}, note = {tex.mendeley-tags: RCC4623,RCC4624,RCC4625,RCC970}, month = {dec}, pages = {29}, keywords = {RCC4623, RCC4624, RCC4625, RCC970}, issn = {2052-4463}, doi = {10.1038/s41597-020-0363-4}, url = {http://www.nature.com/articles/s41597-020-0363-4}, author = {Hackl, Thomas and Martin, Roman and Barenhoff, Karina and Duponchel, Sarah and Heider, Dominik and Fischer, Matthias G.} } @article {Leconte2020, title = {Genome resolved biogeography of mamiellales}, journal = {Genes}, volume = {11}, number = {1}, year = {2020}, note = {tex.mendeley-tags: RCC1105,RCC299,RCC4221: RCC2590,RCC809}, month = {jan}, pages = {66}, abstract = {Among marine phytoplankton, Mamiellales encompass several species from the genera Micromonas, Ostreococcus and Bathycoccus, which are important contributors to primary production. Previous studies based on single gene markers described their wide geographical distribution but led to discussion because of the uneven taxonomic resolution of the method. Here, we leverage genome sequences for six Mamiellales species, two from each genus Micromonas, Ostreococcus and Bathycoccus, to investigate their distribution across 133 stations sampled during the Tara Oceans expedition. Our study confirms the cosmopolitan distribution of Mamiellales and further suggests non-random distribution of species, with two triplets of co-occurring genomes associated with different temperatures: Ostreococcus lucimarinus, Bathycoccus prasinos and Micromonas pusilla were found in colder waters, whereas Ostreococcus spp. RCC809, Bathycoccus spp. TOSAG39-1 and Micromonas commoda were more abundant in warmer conditions. We also report the distribution of the two candidate mating-types of Ostreococcus for which the frequency of sexual reproduction was previously assumed to be very low. Indeed, both mating types were systematically detected together in agreement with either frequent sexual reproduction or the high prevalence of a diploid stage. Altogether, these analyses provide novel insights into Mamiellales{\textquoteright} biogeography and raise novel testable hypotheses about their life cycle and ecology.}, keywords = {Biogeography, mamiellales, mating-type, RCC1105, RCC2590, RCC299, RCC4221, RCC809, sexual reproduction, tara oceans}, issn = {2073-4425}, doi = {10.3390/genes11010066}, url = {https://www.mdpi.com/2073-4425/11/1/66}, author = {Leconte and Benites and Vannier and Wincker and Piganeau and Jaillon} } @article {Belisle2020, title = {Genome sequences of synechococcus sp. Strain MIT S9220 and cocultured cyanophage SynMITS9220M01}, journal = {Microbiology Resource Announcements}, volume = {9}, number = {30}, year = {2020}, note = {tex.mendeley-tags: RCC2571}, month = {jul}, pages = {28{\textendash}30}, abstract = {Synechococcus bacteria are unicellular cyanobacteria that contribute significantly to global marine primary production. We report the nearly complete genome sequence of Synechococcus sp. strain MIT S9220, which lacks the nitrate utilization genes present in most marine Synechococcus genomes. Assembly also produced the complete genome sequence of a cyanophage present in the MIT S9220 culture.}, keywords = {RCC2571}, issn = {2576-098X}, doi = {10.1128/MRA.00481-20}, url = {https://mra.asm.org/content/9/30/e00481-20}, author = {Belisle, B. Shafer and Avila Paz, Andres A. and Carpenter, Angelina R. and Cormier, Tayla C. and Lewis, Adam J. and Menin, Linnea S. and Oliveira, Daniel R and Song, Bukyung and Szeto, Amy and Tchantouridze, Elizabeth I and Watson, Kayleigh A and Yohannes, Mary T and Ahlgren, Nathan A}, editor = {Putonti, Catherine} } @article {Schiffrine2020, title = {Growth and elemental stoichiometry of the ecologically-relevant arctic diatom chaetoceros gelidus: A mix of polar and temperate}, journal = {Frontiers in Marine Science}, volume = {6}, number = {January}, year = {2020}, note = {tex.mendeley-tags: RCC2046}, month = {jan}, keywords = {ammonium, Arctic diatom, ele, Light, nitrate, RCC2046, urea}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00790}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00790/full}, author = {Schiffrine, Nicolas and Tremblay, Jean-{\'e}ric and Babin, Marcel} } @article {Fernandes2020, title = {Hemiselmis andersenii and chlorella stigmatophora as new sources of High-value compounds: A lipidomic approach}, journal = {Journal of Phycology}, year = {2020}, note = {Publisher: Blackwell Publishing Inc. tex.mendeley-tags: RCC661}, month = {aug}, pages = {jpy.13042}, abstract = {To unlock the potential of Chlorella stigmatophora (Trebouxiophyceae, Chlorophyta) and Hemiselmis andersenii (Cryptophyceae, Cryptophyta) as natural reactors for biotechnological exploitation, their lipophilic extracts were characterized using Fourier Transform Infrared spectroscopy with Attenuated Total Reflectance (FTIR-ATR) and Gas Chromatography-Mass Spectrometry (GC-MS) before and after alkaline hydrolysis. The GC-MS analysis enabled the identification of 62 metabolites{\textemdash}namely fatty acids (27), aliphatic alcohols (17), monoglycerides (7), sterols (4), and other compounds (7). After alkaline hydrolysis, monounsaturated fatty acids increased by as much as 87\%, suggesting that the esterified compounds were mainly neutral lipids. Hemiselmis andersenii yielded the highest Σω3/Σω6 ratio (7.26), indicating that it is a good source of ω3 fatty acids, in comparison to C. stigmatophora (Σω3/Σω6 = 1.24). Both microalgae presented significant amounts of aliphatic alcohols (6.81{\textendash}10.95 mg ? g dw-1), which are recognized by their cholesterol-lowering properties. The multivariate analysis allowed visualization of the chemical divergence among H. andersenii lipophilic extracts before and after alkaline hydrolysis, as well as species-specific differences. Chlorella stigmatophora showed to be a valuable source of essential fatty acids for nutraceuticals, whereas H. andersenii, due to its high chemical diversity, seems to be suitable for different fields of application.}, keywords = {Chlorella stigmatophora, GC-MS, Hemiselmis andersenii, lipophilic fraction, Microalgae, RCC661}, issn = {0022-3646}, doi = {10.1111/jpy.13042}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.13042}, author = {Fernandes, Tom{\'a}sia and Cordeiro, Nereida}, editor = {Li, Y.} } @article {bottini_high_2020, title = {High resolution spatial analyses of trace elements in coccoliths reveal new insights into element incorporation in coccolithophore calcite}, journal = {Scientific Reports}, volume = {10}, number = {1}, year = {2020}, note = {Number: 1 Publisher: Nature Publishing Group}, pages = {9825}, abstract = {Coccolithophores are phytoplanktonic algae which produce an exoskeleton made of single platelets of calcite named coccoliths. They are widespread in all oceans and directly impact the short- and long-term C cycle. The study of coccolith size, morphology and elemental composition reveals important information regarding the ability of the cell to calcify and on the factors that influence this process. In this regard, very little is known about coccolith composition and its changes under altered environmental conditions. Here, we present high resolution (50 {\texttimes} 50 nm) elemental spatial distribution in pristine coccoliths of Coccolithus pelagicus and Gephyrocapsa oceanica reconstructed via X-ray fluorescence analyses at synchrotron. The studied specimens are from control culture and metal-enriched (V, Ni, Zn and Pb) experiments. The analysed specimens produced under stress conditions, display an irregular shape and are thinner, especially in the external rim, with ca. 1/3 lower Ca concentrations compared to specimens from the control. The same specimens also have higher Sr/Ca ratio with highest values in the coccolith external rim, suggesting that difficulty in calcification is additionally reflected in increased Sr/Ca ratios. Selenium is found in the coccolith as possible substitute of carbonate in the calcite. V and Pb apparently did not interact with the coccoliths while Zn and Ni were deposited on the coccolith surface.}, keywords = {Environmental chemistry, Environmental impact, Marine chemistry, Pollution remediation, RCC1198, RCC1303}, issn = {2045-2322}, doi = {10.1038/s41598-020-66503-x}, url = {http://www.nature.com/articles/s41598-020-66503-x}, author = {Bottini, Cinzia and Dapiaggi, Monica and Erba, Elisabetta and Faucher, Giulia and Rotiroti, Nicola} } @article {Carrillo2020, title = {Identification and characterization of ChlreSEX4, a novel glucan phosphatase from Chlamydomonas reinhardtii green alga}, journal = {Archives of Biochemistry and Biophysics}, volume = {680}, year = {2020}, note = {Publisher: Academic Press Inc.}, month = {feb}, pages = {108235}, abstract = {Chlamydomonas reinhardtii is the best known unicellular green alga model which has long been used to investigate all kinds of cellular processes, including starch metabolism. Here we identified and characterized a novel enzyme, ChlreSEX4, orthologous to glucan phosphatase SEX4 from Arabidopsis thaliana, that is capable of binding and dephosphorylating amylopectin in vitro. We also reported that cysteine 224 and tryptophan 305 residues are critical for enzyme catalysis and substrate binding. Furthermore, we verified that ChlreSEX4 gene is expressed in vivo and that glucan phosphatase activity is measurable in Chlamydomonas protein extracts. In view of the results presented, we suggest ChlreSEX4 as a functional phosphoglucan phosphatase from C. reinhardtii. Our data obtained so far contribute to understanding the phosphoglucan phosphatases evolutionary process in the green lineage and their role in starch reversible phosphorylation. In addition, this allows to position Chlamydomonas as a potential tool to obtain starches with different degrees of phosphorylation for industrial or biotechnological purposes.}, keywords = {Chlamydomonas Reinhardtii, ChlreSEX4, Glucan phosphatase, SEX4, Starch phosphorylation}, issn = {10960384}, doi = {10.1016/j.abb.2019.108235}, author = {Carrillo, Julieta B. and Torresi, Florencia and Morales, Luisina L. and Ricordi, Micaela and Gomez-Casati, Diego F. and Busi, Maria V. and Mart{\'\i}n, Mariana} } @article {Baumeister2020, title = {Identification to species level of live single microalgal cells from plankton samples with matrix-free laser/desorption ionization mass spectrometry}, journal = {Metabolomics}, volume = {16}, number = {3}, year = {2020}, note = {ISBN: 0123456789 Publisher: Springer US tex.mendeley-tags: RCC 4667,RCC1717,RCC2561,RCC2562,RCC3008,RCC5791,RCC6807,RCC6808,RCC6809,RCC6810,RCC6811,RCC6812,RCC6813,RCC6814,RCC6815,RCC6816,RCC6817,RCC6818,RCC6819,RCC6820,RCC6821}, month = {mar}, pages = {28}, keywords = {ionization high-, Live single-cell mass spectrometry, matrix-free laser desorption, Matrix-free laser desorption/ionization high-resol, Metabolic fingerprinting, Microalgal identification, RCC1717, RCC2561, RCC2562, RCC3008, RCC4667, RCC5791, RCC6807, RCC6808, RCC6809, RCC6810, RCC6811, RCC6812, RCC6813, RCC6814, RCC6815, RCC6816, RCC6817, RCC6818, RCC6819, RCC6820, RCC6821, resolution mass spectrometry, Spectral pattern matching, Spectrum similarity}, issn = {1573-3882}, doi = {10.1007/s11306-020-1646-7}, url = {https://doi.org/10.1007/s11306-020-1646-7 http://link.springer.com/10.1007/s11306-020-1646-7}, author = {Baumeister, Tim U H and Vallet, Marine and Kaftan, Filip and Guillou, Laure and Svato{\v s}, Ale{\v s} and Pohnert, Georg} } @article {Uwizeye2020, title = {In-cell quantitative structural imaging of phytoplankton using 3D electron microscopy}, journal = {bioRxiv}, year = {2020}, note = {tex.mendeley-tags: RCC100,RCC4014,RCC827,RCC909}, month = {jan}, pages = {2020.05.19.104166}, abstract = {Phytoplankton is a minor fraction of the global biomass playing a major role in primary production and climate. Despite improved understanding of phytoplankton diversity and genomics, we lack nanoscale subcellular imaging approaches to understand their physiology and cell biology. Here, we present a complete Focused Ion Beam - Scanning Electron Microscopy (FIB-SEM) workflow (from sample preparation to image processing) to generate nanometric 3D phytoplankton models. Tomograms of entire cells, representatives of six ecologically-successful phytoplankton unicellular eukaryotes, were used for quantitative morphometric analysis. Besides lineage-specific cellular architectures, we observed common features related to cellular energy management: i) conserved cell-volume fractions occupied by the different organelles; ii) consistent plastid-mitochondria interactions, iii) constant volumetric ratios in these energy-producing organelles. We revealed detailed subcellular features related to chromatin organization and to biomineralization. Overall, this approach opens new perspectives to study phytoplankton acclimation responses to abiotic and biotic factors at a relevant biological scale.Competing Interest StatementThe authors have declared no competing interest.}, keywords = {RCC100, RCC4014, RCC827, RCC909}, doi = {10.1101/2020.05.19.104166}, url = {http://biorxiv.org/content/early/2020/05/20/2020.05.19.104166.abstract}, author = {Uwizeye, Clarisse and Decelle, Johan and Jouneau, Pierre-Henri and Gallet, Benoit and Keck, Jean-baptiste and Schwab, Yannick and Schoehn, Guy and Zeeman, Samuel C and Falconet, Denis and Finazzi, Giovanni and Moriscot, Christine and Chevalier, Fabien and Schieber, Nicole L and Templin, Rachel and Curien, Gilles and Schwab, Yannick and Schoehn, Guy and Zeeman, Samuel C and Falconet, Denis and Finazzi, Giovanni} } @article {BlancoAmeijeiras2020, title = {Influence of temperature and CO 2 on Plasma-membrane permeability to CO 2 and HCO 3 - in the marine haptophytes emiliania huxleyi and calcidiscus leptoporus (prymnesiophyceae)}, journal = {Journal of Phycology}, year = {2020}, note = {tex.mendeley-tags: RCC1130,RCC1258}, month = {jun}, pages = {jpy.13017}, abstract = {Membrane permeabilities to CO2 and HCO3- constrain the function of CO2 concentrating mechanisms that algae use to supply inorganic carbon for photosynthesis. In diatoms and green algae, plasma membranes are moderately to highly permeable to CO2 but effectively impermeable to HCO3-. Here, CO2 and HCO3- membrane permeabilities were measured using an 18O-exchange technique on two species of haptophyte algae, Emiliania huxleyi and Calcidiscus leptoporus, which showed that the plasma membranes of these species are also highly permeable to CO2 (0.006{\textendash}0.02 cm ? s-1) but minimally permeable to HCO3-. Increased temperature and CO2 generally increased CO2 membrane permeabilities in both species, possibly due to changes in lipid composition or CO2 channel proteins. Changes in CO2 membrane permeabilities showed no association with the density of calcium carbonate coccoliths surrounding the cell, which could potentially impede passage of compounds. Haptophyte plasma-membrane permeabilities to CO2 were somewhat lower than those of diatoms but generally higher than membrane permeabilities of green algae. One caveat of these measurements is that the model used to interpret 18O-exchange data assumes that carbonic anhydrase, which catalyzes 18O-exchange, is homogeneously distributed in the cell. The implications of this assumption were tested using a two-compartment model with an inhomogeneous distribution of carbonic anhydrase to simulate 18O-exchange data and then inferring plasma-membrane CO2 permeabilities from the simulated data. This analysis showed that the inferred plasma-membrane CO2 permeabilities are minimal estimates but should be quite accurate under most conditions.}, keywords = {carbon concentrating mechanism, CO2, haptophyte, membrane, PERMEABILITY, RCC1130, rcc1258}, issn = {0022-3646}, doi = {10.1111/jpy.13017}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.13017}, author = {Blanco-Ameijeiras, Sonia and Stoll, Heather M. and Zhang, Hongrui and Hopkinson, Brian M.}, editor = {Raven, J.} } @article {Zhang2020, title = {Interactions of thallium with marine phytoplankton}, journal = {Geochimica et Cosmochimica Acta}, volume = {276}, year = {2020}, note = {Publisher: The Author(s) tex.mendeley-tags: RCC1,RCC1242,RCC1353,RCC1557,RCC174,RCC834,RCC950}, pages = {1{\textendash}13}, keywords = {bioaccumulation, biogeochemical cycle, metallome, phytoplankton, RCC1, RCC1242, RCC1353, RCC1557, rcc174, RCC834, RCC950, thallium}, issn = {00167037}, doi = {10.1016/j.gca.2020.02.024}, url = {https://doi.org/10.1016/j.gca.2020.02.024 https://linkinghub.elsevier.com/retrieve/pii/S0016703720301344}, author = {Zhang, Qiong and Rickaby, Rosalind E.M.} } @article {Vigor2020, title = {Isoprostanoid profiling of marine microalgae}, journal = {Biomolecules}, volume = {10}, number = {7}, year = {2020}, note = {Publisher: MDPI AG tex.mendeley-tags: RCC1349,RCC20,RCC69}, month = {jul}, pages = {1073}, abstract = {{\textexclamdown}p{\textquestiondown}Algae result from a complex evolutionary history that shapes their metabolic network. For example, these organisms can synthesize different polyunsaturated fatty acids, such as those found in land plants and oily fish. Due to the presence of numerous double-bonds, such molecules can be oxidized nonenzymatically, and this results in the biosynthesis of high-value bioactive metabolites named isoprostanoids. So far, there have been only a few studies reporting isoprostanoid productions in algae. To fill this gap, the current investigation aimed at profiling isoprostanoids by liquid chromatography -mass spectrometry/mass spectrometry (LC-MS/MS) in four marine microalgae. A good correlation was observed between the most abundant polyunsaturated fatty acids (PUFAs) produced by the investigated microalgal species and their isoprostanoid profiles. No significant variations in the content of oxidized derivatives were observed for Rhodomonas salina and Chaetoceros gracilis under copper stress, whereas increases in the production of C18-, C20- and C22-derived isoprostanoids were monitored in Tisochrysis lutea and Phaeodactylum tricornutum. In the presence of hydrogen peroxide, no significant changes were observed for C. gracilis and for T. lutea, while variations were monitored for the other two algae. This study paves the way to further studying the physiological roles of isoprostanoids in marine microalgae and exploring these organisms as bioresources for isoprostanoid production.{\textexclamdown}/p{\textquestiondown}}, keywords = {Isoprostanoids, Micro-LC-MS/MS, Microalgae, Oxidative stress, PUFAs, RCC1349, RCC20, RCC69}, issn = {2218-273X}, doi = {10.3390/biom10071073}, url = {https://www.mdpi.com/2218-273X/10/7/1073}, author = {Vigor, Claire and Oger, Camille and Reversat, Guillaume and Rocher, Amandine and Zhou, Bingqing and Linares-Maurizi, Amandyne and Guy, Alexandre and Bultel-Ponc{\'e}, Val{\'e}rie and Galano, Jean-Marie and Vercauteren, Joseph and Durand, Thierry and Potin, Philippe and Tonon, Thierry and Leblanc, Catherine} } @article {Langer2020, title = {Li partitioning into coccoliths of Emiliania huxleyi : evaluating the general role of {\textquotedblleft}vital effects{\textquotedblright} in explaining element partitioning in biogenic carbonates}, journal = {Geochemistry, Geophysics, Geosystems}, year = {2020}, note = {ISBN: 0000000272 tex.mendeley-tags: RCC3652}, month = {jun}, pages = {0{\textendash}2}, abstract = {Abstract Emiliania huxleyi cells were grown in artificial seawater of different Li and Ca concentrations and coccolith Li/Ca ratios determined. Coccolith Li/Ca ratios were positively correlated to seawater Li/Ca ratios only if the seawater Li concentration was changed, not if the seawater Ca concentration was changed. This Li partitioning pattern of E. huxleyi was previously also observed in the benthic foraminifer Amphistegina lessonii and inorganically precipitated calcite. We argue that Li partitioning in both E. huxleyi and A. lessonii is dominated by a coupled transmembrane transport of Li and Ca from seawater to the site of calcification. We present a refined version of a recently proposed transmembrane transport model for Li and Ca. The model assumes that Li and Ca enter the cell via Ca channels, the Li flux being dependent on the Ca flux. While the original model features a linear function to describe the experimental data, our refined version uses a power function, changing the stoichiometry of Li and Ca. The version presented here accurately predicts the observed dependence of DLi on seawater Li/Ca ratios. Our data demonstrate that minor element partitioning in calcifying organisms is partly mediated by biological processes even if the partitioning behaviour of the calcifying organism is indistinguishable from that of inorganically precipitated calcium carbonate.}, keywords = {RCC3652}, issn = {1525-2027}, doi = {10.1029/2020GC009129}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GC009129}, author = {Langer, Gerald and Sadekov, Aleksey and Greaves, Mervyn and Nehrke, Gernot and Probert, Ian and Misra, Sambuddha and Thoms, Silke} } @article {Stettin2020, title = {Metabolomics benefits from orbitrap GC{\textendash}MS{\textemdash}Comparison of low- and high-resolution GC{\textendash}MS}, journal = {Metabolites}, volume = {10}, number = {4}, year = {2020}, note = {tex.mendeley-tags: RCC75}, month = {apr}, pages = {143}, abstract = {The development of improved mass spectrometers and supporting computational tools is expected to enable the rapid annotation of whole metabolomes. Essential for the progress is the identification of strengths and weaknesses of novel instrumentation in direct comparison to previous instruments. Orbitrap liquid chromatography (LC){\textendash}mass spectrometry (MS) technology is now widely in use, while Orbitrap gas chromatography (GC){\textendash}MS introduced in 2015 has remained fairly unexplored in its potential for metabolomics research. This study aims to evaluate the additional knowledge gained in a metabolomics experiment when using the high-resolution Orbitrap GC{\textendash}MS in comparison to a commonly used unit-mass resolution single-quadrupole GC{\textendash}MS. Samples from an osmotic stress treatment of a non-model organism, the microalga Skeletonema costatum, were investigated using comparative metabolomics with low- and high-resolution methods. Resulting datasets were compared on a statistical level and on the level of individual compound annotation. Both MS approaches resulted in successful classification of stressed vs. non-stressed microalgae but did so using different sets of significantly dysregulated metabolites. High-resolution data only slightly improved conventional library matching but enabled the correct annotation of an unknown. While computational support that utilizes high-resolution GC{\textendash}MS data is still underdeveloped, clear benefits in terms of sensitivity, metabolic coverage, and support in structure elucidation of the Orbitrap GC{\textendash}MS technology for metabolomics studies are shown here.}, keywords = {Comparative metabolomics, Diatom, High-resolution mass spectrometry (HRMS), Instrument comparison, Mass Spectrometry (Orbitrap GC-MS), Metabolite identification, Orbitrap Gas Chromatography, Osmotic stress, RCC75}, issn = {2218-1989}, doi = {10.3390/metabo10040143}, url = {https://www.mdpi.com/2218-1989/10/4/143}, author = {Stettin, Daniel and Poulin, Remington X. and Pohnert, Georg} } @article {Helliwell2020, title = {A novel single-domain Na +-selective voltage-gated channel in photosynthetic eukaryotes}, journal = {bioRxiv}, year = {2020}, note = {Publisher: Cold Spring Harbor Laboratory tex.mendeley-tags: RCC1456}, month = {apr}, pages = {2020.04.29.068528}, abstract = {The evolution of Na+-selective four-domain voltage-gated channels (4D-Navs) in animals allowed rapid Na+-dependent electrical excitability, and enabled the development of sophisticated systems for rapid and long-range signalling. Whilst bacteria encode single-domain Na+-selective voltage-gated channels (BacNav), they typically exhibit much slower kinetics than 4D-Navs, and are not thought to have crossed the prokaryote-eukaryote boundary. As such, the capacity for rapid Na+-selective signalling is considered to be confined to certain animal taxa, and absent from photosynthetic eukaryotes. Certainly, in land plants, such as the Venus Flytrap where fast electrical excitability has been described, this is most likely based on fast anion channels. Here, we report a unique class of eukaryotic Na+-selective single-domain channels (EukCatBs) that are present primarily in haptophyte algae, including the ecologically important calcifying coccolithophores. The EukCatB channels exhibit very rapid voltage-dependent activation and inactivation kinetics, and sensitivity to the highly selective 4D-Nav blocker tetrodotoxin. The results demonstrate that the capacity for rapid Na+-based signalling in eukaryotes is not restricted to animals or to the presence of 4D-Navs. The EukCatB channels therefore represent an independent evolution of fast Na+-based electrical signalling in eukaryotes that likely contribute to sophisticated cellular control mechanisms operating on very short time scales in unicellular algae. One Sentence Summary The capacity for rapid Na+-based signalling has evolved in ecologically important coccolithophore species via a novel class of voltage-gated Na+ channels, EukCatBs.}, keywords = {RCC1456}, doi = {10.1101/2020.04.29.068528}, url = {https://doi.org/10.1101/2020.04.29.068528}, author = {Helliwell, Katherine E and Chrachri, Abdul and Koester, Julie and Wharam, Susan and Wheeler, Glen L and Brownlee, Colin} } @article {Calmes2020, title = {Parallelisable non-invasive biomass, fitness and growth measurement of macroalgae and other protists with nephelometry}, journal = {Algal Research}, volume = {46}, number = {November 2019}, year = {2020}, note = {Publisher: Elsevier tex.mendeley-tags: RCC149,RCC3088,RCC3510,RCC3553}, pages = {101762}, abstract = {With the exponential development of algal aquaculture and blue biotechnology, there is a strong demand for simple, inexpensive, high-throughput, quantitative phenotyping assays to measure the biomass, growth and fertility of algae and other marine protists. Here, we validate nephelometry, a method that relies on measuring the scattering of light by particles in suspension, as a non-invasive tool to measure in real-time the biomass of aquatic micro-organisms, such as microalgae, filamentous algae, as well as non-photosynthetic protists. Nephelometry is equally applicable to optic density and chlorophyll fluorescence measurements for the quantification of some microalgae, but outperforms other spectroscopy methods to quantify the biomass of biofilm-forming and filamentous algae, highly pigmented species and non-photosynthetic eukaryotes. Thanks to its insensitivity to the sample{\textquoteright}s pigmentation, nephelometry is also the method of choice when chlorophyll content varies between samples or time points, for example due to abiotic stress or pathogen infection. As examples, we illustrate how nephelometry can be combined with fluorometry or image analysis to monitor the quantity and time-course of spore release in fertile kelps or the progression of symptoms in diseased algal cultures.}, keywords = {Algal cultivation, Biomass, Biotechnology, Nephelometry, Phenotyping, RCC149, RCC3088, RCC3510, rcc3553}, issn = {22119264}, doi = {10.1016/j.algal.2019.101762}, url = {https://doi.org/10.1016/j.algal.2019.101762}, author = {Calmes, Beno{\^\i}t and Strittmatter, Martina and Jacquemin, Bertrand and Perrineau, Marie Mathilde and Rousseau, C{\'e}line and Badis, Yacine and Cock, J. Mark and Destombe, Christophe and Valero, Myriam and Gachon, Claire M.M.} } @article {Gebser2020, title = {Phytoplankton-derived zwitterionic gonyol and dimethylsulfonioacetate interfere with microbial dimethylsulfoniopropionate sulfur cycling}, journal = {MicrobiologyOpen}, number = {February}, year = {2020}, note = {tex.mendeley-tags: RCC1731,RCC75,RCC76RCC1217,RCC841}, month = {feb}, pages = {e1014}, keywords = {rcc1217, rcc1731, RCC75, RCC76, RCC841, school of life sciences, university of essex}, issn = {20458827}, doi = {10.1002/mbo3.1014}, url = {http://doi.wiley.com/10.1002/mbo3.1014}, author = {Gebser, Bj{\"o}rn and Thume, Kathleen and Steinke, Michael and Pohnert, Georg} } @article {Aveiro2020, title = {The polar lipidome of cultured emiliania huxleyi: A source of bioactive lipids with relevance for biotechnological applications}, journal = {Biomolecules}, volume = {10}, number = {10}, year = {2020}, note = {tex.ids= Aveiro2020a tex.mendeley-tags: RCC1250 publisher: Multidisciplinary Digital Publishing Institute}, pages = {1434}, abstract = {Polar lipids from microalgae have aroused greater interest as a natural source of omega-3 (n-3) polyunsaturated fatty acids (PUFA), an alternative to fish, but also as bioactive compounds with multiple applications. The present study aims to characterize the polar lipid profile of cultured microalga Emiliania huxleyi using hydrophilic interaction liquid chromatography coupled with high-resolution mass spectrometry (HILIC{\textendash}MS) and fatty acids (FA) analysis by gas chromatography (GC{\textendash}MS). The lipidome of E. huxleyi revealed the presence of distinct n-3 PUFA (40\% of total FA), namely docosahexaenoic acid (22:6n-3) and stearidonic acid (18:4n-3), which give this microalga an increased commercial value as a source of n-3 PUFA present in the form of polar lipids. A total of 134 species of polar lipids were identified and some of these species, particularly glycolipids, have already been reported for their bioactive properties. Among betaine lipids, the diacylglyceryl carboxyhydroxymethylcholine (DGCC) class is the least reported in microalgae. For the first time, monomethylphosphatidylethanolamine (MMPE) has been found in the lipidome of E. huxleyi. Overall, this study highlights the potential of E. huxleyi as a sustainable source of high-value polar lipids that can be exploited for different applications, namely human and animal nutrition, cosmetics, and pharmaceuticals.}, keywords = {Emiliania huxleyi, haptophyta, Lipidomics, Mass spectrometry, Microalgae, RCC1250}, issn = {2218-273X}, doi = {10.3390/biom10101434}, url = {https://www.mdpi.com/2218-273X/10/10/1434}, author = {Aveiro, Susana S. and Melo, T{\^a}nia and Figueiredo, Ana and Domingues, Pedro and Pereira, Hugo and Maia, In{\^e}s B. and Silva, Joana and Domingues, M. Ros{\'a}rio and Nunes, Cl{\'a}udia and Moreira, Ana S. P.} } @article {Avilan2020, title = {ppGpp influences protein protection, growth and photosynthesis in Phaeodactylum tricornutum}, journal = {bioRxiv}, year = {2020}, note = {Publisher: Cold Spring Harbor Laboratory tex.mendeley-tags: RCC2967}, month = {mar}, pages = {2020.03.05.978130}, abstract = {{\textbullet} Chloroplasts retain elements of a bacterial stress response pathway that is mediated by the signalling nucleotides guanosine penta-and tetraphosphate, or (p)ppGpp. In the model flowering plant Arabidopsis, ppGpp acts as a potent regulator of plastid gene expression and influences photosynthesis, plant growth and development. However, little is known about ppGpp metabolism or its evolution in other photosynthetic eukaryotes. {\textbullet} Here, we studied the function of ppGpp in the diatom P. tricornutum using transgenic lines containing an inducible system for ppGpp accumulation. We used these lines to investigate the effects of ppGpp on growth, photosynthesis, lipid metabolism and protein expression. {\textbullet} We demonstrate that ppGpp accumulation reduces photosynthetic capacity and promotes a quiescent-like state with reduced proliferation and ageing. Strikingly, using non-targeted proteomics, we discovered that ppGpp accumulation also leads to the coordinated upregulation of a protein protection response in multiple cellular compartments. {\textbullet} Our findings highlight the importance of ppGpp as a fundamental regulator of chloroplast function across different domains of life, and lead to new questions about the molecular mechanisms and roles of (p)ppGpp signalling in photosynthetic eukaryotes.}, keywords = {chloroplast, diatoms, lipid droplets, Phaeodactylum tricornutum, Photosynthesis, ppGpp, proteome, RCC2967}, doi = {10.1101/2020.03.05.978130}, url = {https://doi.org/10.1101/2020.03.05.978130}, author = {Avilan, Luisana and Lebrun, Regine and Puppo, Carine and Citerne, Sylvie and Cuin{\'e}, Stephane and Li-Beisson, Yonghua and Menand, Benoit and Field, Ben and Gontero, Brigitte} } @article {Morales-Sanchez2020, title = {Production of carbohydrates, lipids and polyunsaturated fatty acids (PUFA) by the polar marine microalga Chlamydomonas malina RCC2488}, journal = {Algal Research}, volume = {50}, number = {July}, year = {2020}, note = {tex.mendeley-tags: RCC2488}, month = {sep}, pages = {102016}, keywords = {RCC2488}, issn = {22119264}, doi = {10.1016/j.algal.2020.102016}, url = {https://linkinghub.elsevier.com/retrieve/pii/S2211926420303477}, author = {Morales-S{\'a}nchez, Daniela and Schulze, Peter S.C. and Kiron, Viswanath and Wijffels, Ren{\'e} H.} } @article {Hepach2020, title = {Senescence as the main driver of iodide release from a diverse range of marine phytoplankton}, journal = {Biogeosciences}, volume = {17}, number = {9}, year = {2020}, note = {tex.mendeley-tags: RC4512,RCC1164,RCC1210,RCC1318,RCC1725,RCC2366,RCC4024,RCC4208,RCC4560}, month = {may}, pages = {2453{\textendash}2471}, keywords = {RCC1164, rcc1210, RCC1318, RCC1725, RCC2366, RCC4024, RCC4208, RCC4512, RCC4560}, issn = {1726-4189}, doi = {10.5194/bg-17-2453-2020}, url = {https://www.biogeosciences.net/17/2453/2020/}, author = {Hepach, Helmke and Hughes, Claire and Hogg, Karen and Collings, Susannah and Chance, Rosie} } @article {Meyer2020, title = {Sr in coccoliths of Scyphosphaera apsteinii: Partitioning behavior and role in coccolith morphogenesis}, journal = {Geochimica et Cosmochimica Acta}, volume = {285}, year = {2020}, note = {Publisher: Elsevier Ltd tex.mendeley-tags: RCC1456}, month = {sep}, pages = {41{\textendash}54}, abstract = {Coccolithophores are important contributors to global calcium carbonate through their species-specific production of calcite coccoliths. Nannofossil coccolith calcite remains an important tool for paleoreconstructions through geochemical analysis of isotopic and trace element incorporation including Sr, which is a potential indicator of past surface ocean temperature and productivity. Scyphosphaera apsteinii (Zygodiscales) exhibits an unusually high Sr/Ca ratio and correspondingly high partitioning coefficient (DSr = 2.5) in their two morphologically distinct types of coccoliths: flat muroliths and barrel-like lopadoliths. Whether or not this reflects mechanistic differences in calcification compared to other coccolithophores is unknown. We therefore examined the possible role of Sr in S. apsteinii calcification by growing cells in deplete (0.33 mmol/mol Sr/Ca), ambient (9 mmol/mol Sr/Ca), and higher than ambient Sr conditions (36 and 72 mmol/mol Sr/Ca). The effects on growth, quantum efficiency of photosystem II (Fv/Fm), coccolith morphology, and calcite DSr were evaluated. No effect on S. apsteinii growth rate or Fv/Fm was observed when cells were grown in Sr/Ca between 0.33{\textendash}36 mmol/mol. However, at 72 mmol/mol Sr/Ca growth rate was significantly reduced, although Fv/Fm was unaffected. Reducing the Sr/Ca from ambient (9 mmol/mol) did not significantly alter the frequency of malformed and aberrant muroliths and lopadoliths, but at higher than ambient Sr/Ca conditions coccolith morphology was significantly disrupted. This implies that Sr is not a critical determining factor in normal coccolith calcite morphology in this dimorphic species. Using energy dispersive spectroscopy (EDS) we observed an increase in [Sr] and decrease in DSr of coccoliths as the Sr/Ca of the growth medium increased. Interestingly, muroliths had significantly lower Sr/Ca than lopadoliths at ambient and elevated [Sr], and lopadolith tips had lower Sr than bases in ambient conditions. In summary, the Sr fractionation behavior of S. apsteinii is distinct from other coccolithophores because of an unusually high DSr and inter- and intra-coccolith variability in Sr/Ca. These observations could be explained by mechanistic differences in the selectivity of the Ca2+ transport pathway or in the Sr-and Ca-binding capacity of organic components, such as polysaccharides associated with coccolithogenesis.}, keywords = {biomineralization, Calcification, coccolith, coccolithophore, Energy dispersive spectroscopy, Fractionation, RCC1456, Sr/Ca, Strontium, Trace element}, issn = {00167037}, doi = {10.1016/j.gca.2020.06.023}, author = {Meyer, Erin M. and Langer, Gerald and Brownlee, Colin and Wheeler, Glen L. and Taylor, Alison R.} } @article {Guyet2020, title = {Synergic effects of temperature and irradiance on the physiology of the marine synechococcus strain WH7803}, journal = {Frontiers in Microbiology}, volume = {11}, year = {2020}, note = {Publisher: Frontiers Media S.A. tex.mendeley-tags: RCC752}, month = {jul}, pages = {1707}, abstract = {Understanding how microorganisms adjust their metabolism to maintain their ability to cope with short-term environmental variations constitutes one of the major current challenges in microbial ecology. Here, the best physiologically characterized marine Synechococcus strain, WH7803, was exposed to modulated light/dark cycles or acclimated to continuous high-light (HL) or low-light (LL), then shifted to various stress conditions, including low (LT) or high temperature (HT), HL and ultraviolet (UV) radiations. Physiological responses were analyzed by measuring time courses of photosystem (PS) II quantum yield, PSII repair rate, pigment ratios and global changes in gene expression. Previously published membrane lipid composition were also used for correlation analyses. These data revealed that cells previously acclimated to HL are better prepared than LL-acclimated cells to sustain an additional light or UV stress, but not a LT stress. Indeed, LT seems to induce a synergic effect with the HL treatment, as previously observed with oxidative stress. While all tested shift conditions induced the downregulation of many photosynthetic genes, notably those encoding PSI, cytochrome b6/f and phycobilisomes, UV stress proved to be more deleterious for PSII than the other treatments, and full recovery of damaged PSII from UV stress seemed to involve the neo-synthesis of a fairly large number of PSII subunits and not just the reassembly of pre-existing subunits after D1 replacement. In contrast, genes involved in glycogen degradation and carotenoid biosynthesis pathways were more particularly upregulated in response to LT. Altogether, these experiments allowed us to identify responses common to all stresses and those more specific to a given stress, thus highlighting genes potentially involved in niche acclimation of a key member of marine ecosystems. Our data also revealed important specific features of the stress responses compared to model freshwater cyanobacteria.}, keywords = {light stress, marine cyanobacteria, rcc752, Synechococcus, temperature stress, transcriptomics, UV radiations}, issn = {1664302X}, doi = {10.3389/fmicb.2020.01707}, url = {www.frontiersin.org}, author = {Guyet, Ulysse and Nguyen, Ngoc A. and Dor{\'e}, Hugo and Haguait, Julie and Pittera, Justine and Conan, Ma{\"e}l and Ratin, Morgane and Corre, Erwan and Le Corguill{\'e}, Gildas and Brillet-Gu{\'e}guen, Loraine and Hoebeke, Mark and Six, Christophe and Steglich, Claudia and Siegel, Anne and Eveillard, Damien and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence} } @article {Derilus2020, title = {Synergism between the Black Queen effect and the proteomic constraint on genome size reduction in the photosynthetic picoeukaryotes}, journal = {Scientific Reports}, volume = {10}, number = {1}, year = {2020}, note = {Publisher: Springer US tex.mendeley-tags: RCC1110,RCC1116,RCC809}, pages = {8918}, keywords = {RCC1110, RCC1116, RCC809}, issn = {2045-2322}, doi = {10.1038/s41598-020-65476-1}, url = {http://dx.doi.org/10.1038/s41598-020-65476-1 http://www.nature.com/articles/s41598-020-65476-1}, author = {Derilus, D and Rahman, M Z and Pinero, F and Massey, S E} } @article {GerikasRibeiro2020, title = {Taxonomic reassignment of \textit{Pseudohaptolina birgeri comb. nov . (Haptophyta)}, journal = {Phycologia}, volume = {in press}, year = {2020}, note = {tex.mendeley-tags: RCC5268,RCC5270}, month = {oct}, pages = {1{\textendash}10}, keywords = {RCC5268, RCC5270}, issn = {0031-8884}, doi = {10.1080/00318884.2020.1830255}, url = {https://www.biorxiv.org/content/10.1101/2020.05.06.081489v1 https://www.tandfonline.com/doi/full/10.1080/00318884.2020.1830255}, author = {G{\'e}rikas Ribeiro, Catherine and Lopes dos Santos, Adriana and Probert, Ian and Vaulot, Daniel and Edvardsen, Bente} } @mastersthesis {Edullantes2020, title = {Thermal responses of marine phytoplankton : Implications to their biogeography in the present and future oceans}, year = {2020}, note = {Number: September tex.mendeley-tags: RCC2649,RCC291,RCC3404}, type = {phd}, keywords = {RCC2649, RCC291, RCC3404}, author = {Edullantes, Brisneve} } @article {Demory2020, title = {A thermal trade-off between viral production and degradation drives phytoplankton-virus population dynamics}, journal = {bioRxiv}, year = {2020}, note = {Publisher: Cold Spring Harbor Laboratory tex.mendeley-tags: RCC4229,RCC4265,RCC451,RCC4523,RCC829,RCC834}, month = {aug}, pages = {2020.08.18.256156}, abstract = {Marine viruses interact with their microbial hosts in dynamic environments shaped by variations in abiotic factors, including temperature. However, the impacts of temperature on viral infection of phytoplankton are not well understood. Here we coupled mathematical modeling with experimental datasets to explore the effect of temperature on three Micromonas-prasinovirus pairs. Our model shows the negative consequences of high temperatures on infection and suggests a temperature-dependent threshold between viral production and degradation. Modeling long-term dynamics in environments with different average temperatures revealed the potential for long-term host-virus coexistence, epidemic free, or habitat loss states. Hence, we generalized our model to global sea surface temperature of present and future seas and show that climate change may influence virus-host dynamics differently depending on the virus-host pair. Our study suggests that temperature-dependent changes in the infectivity of virus particles may lead to shifts in virus-host habitats in warmer oceans, analogous to projected changes in the habitats of macro-and microorganisms .}, keywords = {RCC4229, RCC4265, RCC451, RCC4523, RCC829, RCC834}, doi = {10.1101/2020.08.18.256156}, url = {https://doi.org/10.1101/2020.08.18.256156}, author = {Demory, David and Weitz, Joshua S and Baudoux, Anne-claire and Touzeau, Suzanne and Simon, Natalie and Rabouille, Sophie and Sciandra, Antoine and Bernard, Olivier} } @article {Bretherton2020, title = {Trait-dependent variability of the response of marine phytoplankton to oil and dispersant exposure}, journal = {Marine Pollution Bulletin}, volume = {153}, number = {January}, year = {2020}, note = {Publisher: Elsevier tex.mendeley-tags: RCC1614}, pages = {110906}, abstract = {The Deepwater Horizon oil spill released millions of barrels of crude oil into the Gulf of Mexico, and saw widespread use of the chemical dispersant Corexit. We assessed the role of traits, such as cell size, cell wall, motility, and mixotrophy on the growth and photosynthetic response of 15 phytoplankton taxa to oil and Corexit. We collected growth and photosynthetic data on five algal cultures. These responses could be separated into resistant (Tetraselmis astigmatica, Ochromonas sp., Heterocapsa pygmaea) and sensitive (Micromonas pusilla, Prorocentrum minimum). We combined this data with 10 species previously studied and found that cell size is most important in determining the biomass response to oil, whereas motility/mixotrophy is more important in the dispersed oil. Our analysis accounted for a third of the variance observed, so further work is needed to identify other factors that contribute to oil resistance.}, keywords = {Chemical dispersants, Chlorophyll, crude oil, Photosynthesis, phytoplankton, RCC1614, Trait-based analysis}, issn = {18793363}, doi = {10.1016/j.marpolbul.2020.110906}, url = {https://doi.org/10.1016/j.marpolbul.2020.110906}, author = {Bretherton, Laura and Hillhouse, Jessica and Kamalanathan, Manoj and Finkel, Zoe V. and Irwin, Andrew J. and Quigg, Antonietta} } @article {Pollard2020, title = {A tunable 3D printed microfluidic resistive pulse sensor for the characterisation of algae and microplastics}, journal = {ChemRxiv}, year = {2020}, note = {tex.mendeley-tags: RCC5374,RCC893}, abstract = {Technologies that can detect and characterise particulates in liquids have applications in health, food and environmental monitoring. Here we present a low-cost and high-throughput multiuse counter that classifies a particle{\textquoteright}s size, concentration, porosity and shape. Using an additive manufacturing process, we have assembled a reusable flow resistive pulse sensor. The device remains stable for several days with repeat measurements. We demonstrate its use for characterising algae with spherical and rod structures as well as microplastics shed from teabags. We present a methodology that results in a specific signal for microplastics, namely a conductive pulse, in contrast to particles with smooth surfaces such as calibration particles or algae, allowing the presence of microplastics to be easily confirmed and quantified. In addition, the shape of the signal and particle are correlated, giving an extra physical property to characterise suspended particulates. The technology can rapidly screen volumes of liquid, 1 mL/ min, for the presence of microplastics and algae.}, keywords = {RCC5374, RCC893}, issn = {2187-4247}, doi = {10.26434/chemrxiv.12249833.v1}, author = {Pollard, M. and Hunsicker, E. and Platt, M.} } @booklet {Thomas2020, title = {USE OF AN AMPHIDINOL FOR ITS FUNGICIDAL AND/OR BACTERICIDAL ACTIVITY ON FUNGI, OOMYCETES AND/OR PATHOGENIC BACTERIA OF PLANTS AND CROP SEEDS}, number = {20200100499}, year = {2020}, note = {tex.mendeley-tags: RCC1436}, keywords = {? No DOI found, RCC1436}, url = {http://www.freepatentsonline.com/y2020/0100499.html}, author = {Thomas, Yann and Thiebeauld, Odon} } @article {Tisserand2020, title = {Use of organic exudates from two polar diatoms by bacterial isolates from the Arctic Ocean}, journal = {Philosophical transactions. Series A, Mathematical, physical, and engineering sciences}, volume = {378}, number = {2181}, year = {2020}, note = {Publisher: NLM (Medline) tex.mendeley-tags: RCC2278,RCC4289}, month = {oct}, pages = {20190356}, abstract = {Global warming affects primary producers in the Arctic, with potential consequences for the bacterial community composition through the consumption of microalgae-derived dissolved organic matter (DOM). To determine the degree of specificity in the use of an exudate by bacterial taxa, we used simple microalgae-bacteria model systems. We isolated 92 bacterial strains from the sea ice bottom and the water column in spring-summer in the Baffin Bay (Arctic Ocean). The isolates were grouped into 42 species belonging to Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. Forty strains were tested for their capacity to grow on the exudate from two Arctic diatoms. Most of the strains tested (78\%) were able to grow on the exudate from the pelagic diatom Chaetoceros neogracilis, and 33\% were able to use the exudate from the sea ice diatom Fragilariopsis cylindrus. 17.5\% of the strains were not able to grow with any exudate, while 27.5\% of the strains were able to use both types of exudates. All strains belonging to Flavobacteriia (n = 10) were able to use the DOM provided by C. neogracilis, and this exudate sustained a growth capacity of up to 100 times higher than diluted Marine Broth medium, of two Pseudomonas sp. strains and one Sulfitobacter strain. The variable bioavailability of exudates to bacterial strains highlights the potential role of microalgae in shaping the bacterial community composition. This article is part of the theme issue {\textquoteright}The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning{\textquoteright}.}, keywords = {Arctic Ocean, bacterial diversity, bacterial isolation, biodegradation, diatoms, dissolved organic exudates, RCC2278, RCC4289}, issn = {14712962}, doi = {10.1098/rsta.2019.0356}, url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2019.0356}, author = {Tisserand, Lucas and Dadaglio, La{\"e}titia and Intertaglia, Laurent and Catala, Philippe and Panagiotopoulos, Christos and Obernosterer, Ingrid and Joux, Fabien} } @article {Yau2020, title = {Virus-host coexistence in phytoplankton through the genomic lens}, journal = {Science Advances}, volume = {6}, number = {14}, year = {2020}, note = {tex.mendeley-tags: RCC2590,RCC2596}, month = {apr}, pages = {eaay2587}, abstract = {Virus-microbe interactions in the ocean are commonly described by {\textquotedblleft}boom and bust{\textquotedblright} dynamics, whereby a numerically dominant microorganism is lysed and replaced by a virus-resistant one. Here, we isolated a microalga strain and its infective dsDNA virus whose dynamics are characterized instead by parallel growth of both the microalga and the virus. Experimental evolution of clonal lines revealed that this viral production originates from the lysis of a minority of virus-susceptible cells, which are regenerated from resistant cells. Whole-genome sequencing demonstrated that this resistant-susceptible switch involved a large deletion on one chromosome. Mathematical modeling explained how the switch maintains stable microalga-virus population dynamics consistent with their observed growth pattern. Comparative genomics confirmed an ancient origin of this {\textquotedblleft}accordion{\textquotedblright} chromosome despite a lack of sequence conservation. Together, our results show how dynamic genomic rearrangements may account for a previously overlooked coexistence mechanism in microalgae-virus interactions.}, keywords = {RCC2590, RCC2596}, issn = {2375-2548}, doi = {10.1126/sciadv.aay2587}, url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aay2587}, author = {Yau, Sheree and Krasovec, Marc and Benites, L. Felipe and Rombauts, Stephane and Groussin, Mathieu and Vancaester, Emmelien and Aury, Jean-Marc and Derelle, Evelyne and Desdevises, Yves and Escande, Marie-Line and Grimsley, Nigel and Guy, Julie and Moreau, Herv{\'e} and Sanchez-Brosseau, Sophie and Van de Peer, Yves and Vandepoele, Klaas and Gourbi{\`e}re, S{\'e}bastien and Piganeau, Gwenael} } @article {Castillo2020, title = {Visualization of viral infection dynamics in a unicellular eukaryote and quantification of viral production using virus fluorescence in situ hybridization}, journal = {Frontiers in Microbiology}, volume = {11}, year = {2020}, note = {Publisher: Frontiers Media S.A. tex.mendeley-tags: RCC4221}, month = {jul}, pages = {1559}, abstract = {One of the major challenges in viral ecology is to assess the impact of viruses in controlling the abundance of specific hosts in the environment. To this end, techniques that enable the detection and quantification of virus-host interactions at the single-cell level are essential. With this goal in mind, we implemented virus fluorescence in situ hybridization (VirusFISH) using as a model the marine picoeukaryote Ostreococcus tauri and its virus Ostreococcus tauri virus 5 (OtV5). VirusFISH allowed the visualization and quantification of the proportion of infected cells during an infection cycle in experimental conditions. We were also able to quantify the abundance of free viruses released during cell lysis, discriminating OtV5 from other mid-level fluorescence phages in our non-axenic infected culture that were not easily distinguishable with flow cytometry. Our results showed that although the major lysis of the culture occurred between 24 and 48 h after OtV5 inoculation, some new viruses were already produced between 8 and 24 h. With this work, we demonstrate that VirusFISH is a promising technique to study specific virus-host interactions in non-axenic cultures and establish a framework for its application in complex natural communities.}, keywords = {culture system, marine picoeukaryote, Ostreococcus tauri, Ostreococcus tauri virus 5, RCC4221, virus fluorescence in situ hybridization, virus-host interactions}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.01559}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2020.01559/full}, author = {Castillo, Yaiza M. and Sebasti{\'a}n, Marta and Forn, Irene and Grimsley, Nigel and Yau, Sheree and Moraru, Cristina and Vaqu{\'e}, Dolors} } @article {Decelle2019, title = {Algal remodeling in a ubiquitous planktonic photosymbiosis}, journal = {Current Biology}, volume = {29}, number = {6}, year = {2019}, note = {Publisher: Cell Press tex.mendeley-tags: RCC1719}, month = {mar}, pages = {968{\textendash}978.e4}, abstract = {Photosymbiosis between single-celled hosts and microalgae is common in oceanic plankton, especially in oligotrophic surface waters. However, the functioning of this ecologically important cell-cell interaction and the subcellular mechanisms allowing the host to accommodate and benefit from its microalgae remain enigmatic. Here, using a combination of quantitative single-cell structural and chemical imaging techniques (FIB-SEM, nanoSIMS, Synchrotron X-ray fluorescence), we show that the structural organization, physiology, and trophic status of the algal symbionts (the haptophyte Phaeocystis) significantly change within their acantharian hosts compared to their free-living phase in culture. In symbiosis, algal cell division is blocked, photosynthesis is enhanced, and cell volume is increased by up to 10-fold with a higher number of plastids (from 2 to up to 30) and thylakoid membranes. The multiplication of plastids can lead to a 38-fold increase of the total plastid volume in a cell. Subcellular mapping of nutrients (nitrogen and phosphorous) and their stoichiometric ratios shows that symbiotic algae are impoverished in phosphorous and suggests a higher investment in energy-acquisition machinery rather than in growth. Nanoscale imaging also showed that the host supplies a substantial amount of trace metals (e.g., iron and cobalt), which are stored in algal vacuoles at high concentrations (up to 660 ppm). Sulfur mapping reveals a high concentration in algal vacuoles that may be a source of antioxidant molecules. Overall, this study unveils an unprecedented morphological and metabolic transformation of microalgae following their integration into a host, and it suggests that this widespread symbiosis is a farming strategy wherein the host engulfs and exploits microalgae.}, keywords = {RCC1719}, issn = {0960-9822}, doi = {10.1016/J.CUB.2019.01.073}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0960982219301320$\#$undfig1}, author = {Decelle, Johan and Stryhanyuk, Hryhoriy and Gallet, Benoit and Veronesi, Giulia and Schmidt, Matthias and Balzano, Sergio and Marro, Sophie and Uwizeye, Clarisse and Jouneau, Pierre-Henri and Lupette, Josselin and Jouhet, Juliette and Mar{\'e}chal, {\'E}ric and Schwab, Yannick and Schieber, Nicole L. and Tucoulou, R{\'e}mi and Richnow, Hans and Finazzi, Giovanni and Musat, Niculina} } @article {Helliwell2019, title = {Alternative mechanisms for fast na + /ca 2+ signaling in eukaryotes via a novel class of single-domain voltage-gated channels}, journal = {Current Biology}, volume = {29}, number = {9}, year = {2019}, note = {tex.mendeley-tags: RCC299}, pages = {1503{\textendash}1511.e6}, abstract = {Rapid Na + /Ca 2+ -based action potentials govern essential cellular functions in eukaryotes, from the motile responses of unicellular protists, such as Paramecium [1, 2], to complex animal neuromuscular activity [3]. A key innovation underpinning this fundamental signaling process has been the evolution of four-domain voltage-gated Na + /Ca 2+ channels (4D-Ca v s/Na v s). These channels are widely distributed across eukaryote diversity [4], albeit several eukaryotes, including land plants and fungi, have lost voltage-sensitive 4D-Ca v /Na v s [5{\textendash}7]. Because these lineages appear to lack rapid Na + /Ca 2+ -based action potentials, 4D-Ca v /Na v s are generally considered necessary for fast Na + /Ca 2+ -based signaling [7]. However, the cellular mechanisms underpinning the membrane physiology of many eukaryotes remain unexamined. Eukaryotic phytoplankton critically influence our climate as major primary producers. Several taxa, including the globally abundant diatoms, exhibit membrane excitability [8{\textendash}10]. We previously demonstrated that certain diatom genomes encode 4D-Ca v /Na v s [4] but also proteins of unknown function, resembling prokaryote single-domain, voltage-gated Na + channels (BacNa v s) [4]. Here, we show that single-domain channels are actually broadly distributed across major eukaryote phytoplankton lineages and represent three novel classes of single-domain channels, which we refer collectively to as EukCats. Functional characterization of diatom EukCatAs indicates that they are voltage-gated Na + - and Ca 2+ -permeable channels, with rapid kinetics resembling metazoan 4D-Ca v s/Na v s. In Phaeodactylum tricornutum, which lacks 4D-Ca v /Na v s, EukCatAs underpin voltage-activated Ca 2+ signaling important for membrane excitability, and mutants exhibit impaired motility. EukCatAs therefore provide alternative mechanisms for rapid Na + /Ca 2+ signaling in eukaryotes and may functionally replace 4D-Ca v s/Na v s in pennate diatoms. Marine phytoplankton thus possess unique signaling mechanisms that may be key to environmental sensing in the oceans. Diatoms exhibit fast animal-like action potentials, but many species lack 4D-Ca v /Na v channels that underpin membrane excitability in animals. Diatoms do encode novel 1D voltage-gated channels (EukCatAs). Helliwell, Chrachri et al. show that EukCatAs are fast Na + and Ca 2+ channels that provide alternative mechanisms for rapid signaling in eukaryotes.}, keywords = {action potentials, BacNa v, calcium channel, diatoms, EukCats, gliding motility, ion selectivity, RCC299, signaling, single-domain channel, voltage-gated channel}, issn = {09609822}, doi = {10.1016/j.cub.2019.03.041}, author = {Helliwell, Katherine E. and Chrachri, Abdul and Koester, Julie A. and Wharam, Susan and Verret, Frederic and Taylor, Alison R. and Wheeler, Glen L. and Brownlee, Colin} } @article {Zimmerman2019, title = {Closely related viruses of the marine picoeukaryotic alga Ostreococcus lucimarinus exhibit different ecological strategies}, journal = {Environmental Microbiology}, volume = {00}, year = {2019}, note = {tex.mendeley-tags: RCC3401,RCC393,RCC829}, abstract = {SUMMARY In marine ecosystems viruses are major disrupters of the direct flow of carbon and nutrients to higher trophic levels. While the genetic diversity of several eukaryotic phytoplankton virus groups has been characterized, their infection dynamics are less understood, such that the physiological and ecological implications of their diversity remain unclear. We compared genomes and infection phenotypes of the two most closely related cultured phycodnaviruses infecting the widespread picoprasinophyte Ostreococcus lucimarinus under standard- (1.3 divisions d-1) and limited-light (0.41 divisions d-1) nutrient replete conditions. OlV7 infection caused early arrest of the host cell cycle, coinciding with a significantly higher proportion of infected cells than OlV1-amended treatments, regardless of host growth rate. OlV7 treatments showed a near-50-fold increase of progeny virions at the higher host growth rate, contrasting with OlV1{\textquoteright}s 16-fold increase. However, production of OlV7 virions was more sensitive than OlV1 production to reduced host growth rate, suggesting fitness trade-offs between infection efficiency and resilience to host physiology. Moreover, while organic matter released from OlV1- and OlV7-infected hosts had broadly similar chemical composition, some distinct molecular signatures were observed. Collectively, these results suggest that current views on viral relatedness through marker and core gene analyses underplay operational divergence and consequences for host ecology. This article is protected by copyright. All rights reserved.}, keywords = {rcc3401, RCC393, RCC829}, issn = {14622920}, doi = {10.1111/1462-2920.14608}, author = {Zimmerman, Amy E. and Bachy, Charles and Ma, Xiufeng and Roux, Simon and Jang, Ho Bin and Sullivan, Matthew B. and Waldbauer, Jacob R. and Worden, Alexandra Z.} } @mastersthesis {VanTol2019, title = {Computational and experimental models of diatom-bacteria interaction}, year = {2019}, note = {ISBN: 9781085779104 Pages: 161 Publication title: ProQuest dissertations and theses tex.mendeley-tags: RCC80}, type = {phd}, abstract = {Microbial interactions structure ecosystems and fuel biogeochemical cycling. The metabolic activities operating in the ocean are critical to the entire planet. In this work, I focused on interactions between diatoms and heterotrophic bacteria. Diatoms are a group of unicellular brown algae with frustules composed of silica. They form the base of coastal and polar marine food webs and contribute one fifth of global primary productivity. The inorganic nutrients fixed by oxygenic photosynthesis fuel secondary productivity by marine bacteria. Marine bacteria and diatoms have a range of different interaction strategies; many are still being elucidated.In Chapter 1, I studied the antagonistic effects of a flavobacterium on diatom cell division. Croceibacter atlanticus inhibits cytokinesis in many species, causing the cells to elongate, become mutlinucleated, and filled with plastids.In Chapter 2, I created a metabolic model of the diatom Thalassiosira pseudonana using the genome and physiological data from the literature. Simulations of diatom growth using Flux Balance Analysis revealed a role for nitrate and sulfate assimilation in dissipating reductants from the plastid. Changing redox and nutrient conditions causes the cell to secrete metabolites including organic carbon, nitrogen, and sulfur.In Chapter 3, I created a metabolic model of the B12-producing alphaproteobacterium Ruegeria pomeroyi. Previous work has demonstrated that R. pomeroyi will provide cobalamin to T. pseudonana in B12-starvation conditions in exchange for organic sulfur and nitrogen. I constrained the metabolic models with transcriptomic data of T. pseudonana and R. pomeroyi in co-culture and simulated their interaction.The distinct character of metabolites produced by diatoms likely fuels interactions with bacteria capable of utilizing those molecules. Bacteria influence diatom metabolism by interfering with the cell cycle, through nutrient-limitation, by altering redox conditions, and providing the cofactors required for growth. In this work, I have contributed to the literature exploring the complexity of diatom-bacteria interactions, where chemical or peptide cues, signals, and antagonists underlie the dynamics of microbial interactions. I have also created a framework for exploring more general metabolic exchanges between diatoms and bacteria. Genome-scale metabolic modeling of interactions between distinct marine microbial communities may be key to accurately predicting the character of dissolve organic matter in the ocean.}, keywords = {Croceibacter atlanticus, diatoms, Genome-scale met, RCC80}, url = {https://remotexs.ntu.edu.sg/user/login?url=https://search.proquest.com/docview/2305846221?accountid=12665}, author = {van Tol, Helena M} } @article {kusch_dead_2019, title = {Dead in the Water: The Vicious Cycle of Blanks During Natural Level 14 C Manipulation of Marine Algal Cultures}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, note = {Publisher: Frontiers}, abstract = {Authentic biomarker standards were obtained from algal cultures in an attempt to accurately determine blank C added during sample processing for compound-specific radiocarbon analysis. Emiliania huxleyi and Thalassiosira pseudonana were grown under manipulated Δ14C dissolved inorganic carbon (DIC) levels and chlorophyll a and either alkenones (E. huxleyi) or low molecular weight (LMW) alkanoic acids (T. pseudonana) were isolated from the respective biomass using preparative liquid chromatography (LC), wet chemical techniques or preparative gas chromatography, respectively. DI14C in the seawater medium was determined pre- and post-growth. Biomarker Δ14C values mostly agree within 1-2? analytical uncertainties. In those cases where biomarker Δ14C values differ significantly, chlorophyll a is up to 104{\textperthousand} more 14C-depleted than alkenones or LMW alkanoic acids, consistent with a larger LC blank compared to the other purification methods. However, in the majority of experimental setups pre- and post-growth DIC Δ14C values seem to be compromised by an unknown and variable blank C contribution. DIC Δ14C values deviate strongly from the anticipated Δ14C values (by up to ca. 560{\textperthousand}), pre- and post-growth Δ14C values differ significantly (by up to ca. 460{\textperthousand}), and changes are not unidirectional. Accordingly, since the substrate Δ14C value cannot unequivocally be constrained, blank C contributions for the different biomarker purification methods cannot be accurately calculated. This study illustrates the challenges and problems of producing authentic standards that are not readily commercially available and exemplifies how a laborious and time-consuming culturing approach may enter a vicious cycle of blank C contamination hampering accurate blank C determination.}, keywords = {Algal cultures, Alkanoic acids, alkenones, Authentic standards, Blank, chlorophyll a, Compound-specific radiocarbon analysis, natural level 14 C manipulation, rcc1238}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00780}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2019.00780/full}, author = {Kusch, Stephanie and Benthien, Albert and Richter, Klaus-Uwe and Rost, Bj{\"o}rn and Mollenhauer, Gesine} } @article {Lacour2019, title = {Decoupling light harvesting, electron transport and carbon fixation during prolonged darkness supports rapid recovery upon re-illumination in the Arctic diatom Chaetoceros neogracilis}, journal = {Polar Biology}, year = {2019}, note = {ISBN: 0123456789 Publisher: Springer Berlin Heidelberg tex.mendeley-tags: RCC2278}, month = {may}, keywords = {Arctic microalgae, Darkness, Diatom, GROWTH RATE, Photosynthesis, Polar night, RCC2278, temperature}, issn = {0722-4060}, doi = {10.1007/s00300-019-02507-2}, url = {https://doi.org/10.1007/s00300-019-02507-2 http://link.springer.com/10.1007/s00300-019-02507-2}, author = {Lacour, Thomas and Morin, Philippe-Isra{\"e}l and Sciandra, Th{\'e}o and Donaher, Natalie and Campbell, Douglas A. and Ferland, Joannie and Babin, Marcel} } @article {Lorenzo2019, title = {Effects of elevated co 2 on growth, calcification and spectral dependence of photoinhibition in the coccolithophore Emiliania huxleyi (Prymnesiophyceae)}, journal = {Journal of Phycology}, year = {2019}, note = {tex.mendeley-tags: RCC1226}, month = {may}, pages = {jpy.12885}, keywords = {rcc1226}, issn = {0022-3646}, doi = {10.1111/jpy.12885}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.12885}, author = {Lorenzo, M. Rosario and Neale, Patrick J. and Sobrino, Cristina and Le{\'o}n, Pablo and V{\'a}zquez, V{\'\i}ctor and Bresnan, Eileen and Segovia, Mar{\'\i}a} } @article {Krasovec2019, title = {First estimation of the spontaneous mutation rate in Diatoms}, journal = {Genome Biology and Evolution}, volume = {1}, year = {2019}, note = {tex.mendeley-tags: RCC2967}, pages = {1{\textendash}23}, keywords = {diatoms, Mutation accumulation, mutation rate in phaeodactylum, mutation spectrum, phaeodactylum, RCC2967, running title, spontaneous mutation rate, tricornutum}, issn = {1759-6653}, doi = {10.1093/gbe/evz130}, url = {https://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evz130/5520952}, author = {Krasovec, Marc and Sanchez-Brosseau, Sophie and Piganeau, Gwenael}, editor = {Baer, Charles} } @article {Arsenieff2019, title = {First viruses infecting the marine diatom guinardia delicatula}, journal = {Frontiers in Microbiology}, volume = {9}, number = {January}, year = {2019}, note = {tex.mendeley-tags: RCC1000,RCC2023,RCC3046,RCC3083,RCC3093,RCC3101,RCC4657,RCC4659,RCC4660,RCC4667,RCC4834,RCC5154,RCC5777,RCC5778,RCC5779,RCC5780,RCC5781,RCC5782,RCC5783,RCC5784,RCC5785,RCC5787,RCC5788,RCC5789,RCC5790,RCC5792,RCC5793,RCC5794,RCC80}, month = {jan}, keywords = {diatoms, genomics, host-virus dynamics, RCC1000, RCC2023, RCC3046, RCC3083, RCC3093, RCC3101, RCC4657, RCC4659, RCC4660, RCC4667, RCC4834, RCC5154, RCC5777, RCC5778, RCC5779, RCC5780, RCC5781, RCC5782, RCC5783, RCC5784, RCC5785, RCC5787, RCC5788, RCC5789, RCC5790, RCC5792, RCC5793, RCC5794, RCC80, single-stranded RNA viruses, Western English Channel}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.03235}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2018.03235/full}, author = {Arsenieff, Laure and Simon, Nathalie and Rigaut-jalabert, Fabienne and Le Gall, Florence and Chaffron, Samuel and Corre, Erwan and Com, Emmanuelle and Bigeard, Estelle and Baudoux, Anne-claire} } @article {Weiss2019, title = {Hydrogen isotope fractionation response to salinity and alkalinity in a calcifying strain of Emiliania huxleyi}, journal = {Organic Geochemistry}, year = {2019}, note = {Publisher: Elsevier Ltd tex.mendeley-tags: RCC2050}, month = {jun}, keywords = {RCC2050}, issn = {01466380}, doi = {10.1016/j.orggeochem.2019.06.001}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0146638019301020}, author = {Weiss, Gabriella M. and Roepert, Anne and Middelburg, Jack J. and Schouten, Stefan and Sinninghe Damst{\'e}, Jaap S. and van der Meer, Marcel T.J.} } @article {Lim2019, title = {In vitro enzymatic activity assays implicate the existence of the chlorophyll cycle in chlorophyll b-Containing cyanobacteria}, journal = {Plant and Cell Physiology}, number = {August}, year = {2019}, note = {tex.mendeley-tags: RCC1774}, month = {aug}, pages = {1{\textendash}12}, abstract = {In plants, chlorophyll (Chl) a and b are interconvertible by the action of three enzymes{\textemdash}chlorophyllide a oxygenase, Chl b reductase (CBR) and 7-hydroxymethyl chlorophyll a reductase (HCAR). These reactions are collectively referred to as the Chl cycle. In plants, this cyclic pathway ubiquitously exists and plays essential roles in acclimation to different light conditions at various developmental stages. By contrast, only a limited number of cyanobacteria species produce Chl b, and these include Prochlorococcus, Prochloron, Prochlorothrix and Acaryochloris. In this study, we investigated a possible existence of the Chl cycle in Chl b synthesizing cyanobacteria by testing in vitro enzymatic activities of CBR and HCAR homologs from Prochlorothrix hollandica and Acaryochloris RCC1774. All of these proteins show respective CBR and HCAR activity in vitro, indicating that both cyanobacteria possess the potential to complete the Chl cycle. It is also found that CBR and HCAR orthologs are distributed only in the Chl b-containing cyanobacteria that habitat shallow seas or freshwater, where light conditions change dynamically, whereas they are not found in Prochlorococcus species that usually habitat environments with fixed lighting. Taken together, our results implicate a possibility that the Chl cycle functions for light acclimation in Chl b-containing cyanobacteria.}, keywords = {chlorophyll cyanobacterium, evolution promiscuous activity, RCC1774}, issn = {0032-0781}, doi = {10.1093/pcp/pcz157}, url = {https://academic.oup.com/pcp/advance-article/doi/10.1093/pcp/pcz157/5544940}, author = {Lim, Hyunseok and Tanaka, Ayumi and Tanaka, Ryouichi and Ito, Hisashi} } @article {Granata2019, title = {The influence of bio-optical properties of Emiliania huxleyi and Tetraselmis sp. on biomass and lipid production when exposed to different light spectra and intensities of an adjustable LED array and standard light sources}, journal = {SN Applied Sciences}, volume = {1}, number = {6}, year = {2019}, note = {ISBN: 0123456789 Publisher: Springer International Publishing tex.mendeley-tags: RCC1210,RCC2604}, month = {jun}, pages = {524}, keywords = {Bio-optical properties, Biomass and lipid production, jel classification q42, mathematics subject classification 92c99, rcc1210, RCC2604, Spectral irradiance}, issn = {2523-3963}, doi = {10.1007/s42452-019-0529-x}, url = {http://link.springer.com/10.1007/s42452-019-0529-x}, author = {Granata, Tim and Habermacher, Patrick and H{\"a}rri, Vinzenz and Egli, Marcel} } @article {Sanfilippo2019, title = {Interplay between differentially expressed enzymes contributes to light color acclimation in marine Synechococcus}, journal = {Proceedings of the National Academy of Sciences}, volume = {116}, number = {13}, year = {2019}, note = {tex.mendeley-tags: RCC1086,RCC2035,RCC2380,RCC2382,RCC2385,RCC2433,RCC2437,RCC2528,RCC2533,RCC2534,RCC2535,RCC2571,RCC2673,RCC28,RCC307,RCC328,RCC515,RCC555,RCC791}, month = {mar}, pages = {6457{\textendash}6462}, abstract = {Marine Synechococcus , a globally important group of cyanobacteria, thrives in various light niches in part due to its varied photosynthetic light-harvesting pigments. Many Synechococcus strains use a process known as chromatic acclimation to optimize the ratio of two chromophores, green-light{\textendash}absorbing phycoerythrobilin (PEB) and blue-light{\textendash}absorbing phycourobilin (PUB), within their light-harvesting complexes. A full mechanistic understanding of how Synechococcus cells tune their PEB to PUB ratio during chromatic acclimation has not yet been obtained. Here, we show that interplay between two enzymes named MpeY and MpeZ controls differential PEB and PUB covalent attachment to the same cysteine residue. MpeY attaches PEB to the light-harvesting protein MpeA in green light, while MpeZ attaches PUB to MpeA in blue light. We demonstrate that the ratio of mpeY to mpeZ mRNA determines if PEB or PUB is attached. Additionally, strains encoding only MpeY or MpeZ do not acclimate. Examination of strains of Synechococcus isolated from across the globe indicates that the interplay between MpeY and MpeZ uncovered here is a critical feature of chromatic acclimation for marine Synechococcus worldwide.}, keywords = {RCC1086, RCC2035, rcc2380, rcc2382, RCC2385, RCC2433, RCC2437, RCC2528, RCC2533, RCC2534, RCC2535, RCC2571, RCC2673, RCC28, RCC307, RCC328, RCC515, rcc555, rcc791}, issn = {0027-8424}, doi = {10.1073/pnas.1810491116}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1810491116}, author = {Sanfilippo, Joseph E. and Nguyen, Adam A. and Garczarek, Laurence and Karty, Jonathan A. and Pokhrel, Suman and Strnat, Johann A. and Partensky, Fr{\'e}d{\'e}ric and Schluchter, Wendy M. and Kehoe, David M.} } @article {LevyKarin2019, title = {MetaEuk {\textendash} sensitive, high-throughput gene discovery and annotation for large-scale eukaryotic metagenomics}, journal = {bioRxiv}, year = {2019}, month = {jan}, pages = {851964}, abstract = {Background: Metagenomics is revolutionizing the study of microorganisms and their involvement in biological, biomedical, and geochemical processes, allowing us to investigate by direct sequencing a tremendous diversity of organisms without the need for prior cultivation. Unicellular eukaryotes play essential roles in most microbial communities as chief predators, decomposers, phototrophs, bacterial hosts, symbionts and parasites to plants and animals. Investigating their roles is therefore of great interest to ecology, biotechnology, human health, and evolution. However, the generally lower sequencing coverage, their more complex gene and genome architectures, and a lack of eukaryote-specific experimental and computational procedures have kept them on the sidelines of metagenomics. Results: MetaEuk is a toolkit for high-throughput, reference-based discovery and annotation of protein-coding genes in eukaryotic metagenomic contigs. It performs fast searches with 6-frame-translated fragments covering all possible exons and optimally combines matches into multi-exon proteins. We used a benchmark of seven diverse, annotated genomes to show that MetaEuk is highly sensitive even under conditions of low sequence similarity to the reference database. To demonstrate MetaEuk\&\#039;s power to discover novel eukaryotic proteins in large-scale metagenomic data, we assembled contigs from 912 samples of the Tara Oceans project. MetaEuk predicted \>12,000,000 protein-coding genes in eight days on ten 16-core servers. Most of the discovered proteins are highly diverged from known proteins and originate from very sparsely sampled eukaryotic supergroups. Conclusion: The open-source (GPLv3) MetaEuk software (https://github.com/soedinglab/metaeuk) enables large-scale eukaryotic metagenomics through reference-based, sensitive taxonomic and functional annotation.}, doi = {10.1101/851964}, url = {http://biorxiv.org/content/early/2019/11/25/851964.abstract}, author = {Levy Karin, Eli and Mirdita, Milot and Soeding, Johannes} } @article {Klintzsch2019, title = {Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment}, journal = {Biogeosciences}, volume = {16}, number = {20}, year = {2019}, note = {tex.mendeley-tags: RCC1216}, month = {oct}, pages = {4129{\textendash}4144}, keywords = {RCC1216}, issn = {1726-4189}, doi = {10.5194/bg-16-4129-2019}, url = {https://www.biogeosciences.net/16/4129/2019/}, author = {Klintzsch, Thomas and Langer, Gerald and Nehrke, Gernot and Wieland, Anna and Lenhart, Katharina and Keppler, Frank} } @article {Iglesias2019, title = {NMR characterization and evaluation of antibacterial and antiobiofilm activity of organic extracts from stationary phase batch cultures of five marine microalgae (Dunaliella sp., D. salina, Chaetoceros calcitrans, C. gracilis and Tisochrysis lutea)}, journal = {Phytochemistry}, volume = {164}, number = {April}, year = {2019}, note = {Publisher: Elsevier tex.mendeley-tags: RCC1349,RCC1811,RCC3579,RCC5,RCC5953}, month = {aug}, pages = {192{\textendash}205}, keywords = {Antibacterial, Antibiofilm, Chaetoceros, Dunaliella, Metabolite identification, NMR, RCC1349, RCC1811, RCC3579, RCC5, RCC5953, Tisochrysis}, issn = {00319422}, doi = {10.1016/j.phytochem.2019.05.001}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0031942219300184}, author = {Iglesias, Ma Jos{\'e} and Soengas, Raquel and Probert, Ian and Guilloud, Emilie and Gourvil, Priscillia and Mehiri, Mohamed and L{\'o}pez, Yuly and Cepas, Virginio and Guti{\'e}rrez-del-R{\'\i}o, Ignacio and Redondo-Blanco, Sa{\'u}l and Villar, Claudio J. and Lomb{\'o}, Felipe and Soto, Sara and Ortiz, Fernando L{\'o}pez} } @article {Gafar2019, title = {Particulate inorganic to organic carbon production as a predictor for coccolithophorid sensitivity to ongoing ocean acidification}, journal = {Limnology and Oceanography Letters}, volume = {4}, number = {3}, year = {2019}, note = {Publisher: John Wiley \& Sons, Ltd tex.mendeley-tags: RCC1130,RCC1141,RCC1168,RCC1198,RCC1200,RCC1323,RCC1334}, month = {jun}, pages = {62{\textendash}70}, abstract = {Ocean acidification (OA) can induce shifts in plankton community composition, with coccolithophores being mostly negatively impacted. This is likely to change particulate inorganic and organic carbon (PIC and POC, respectively) production, with impacts on the biological carbon pump. Hence, assessing and, most importantly, understanding species-specific sensitivities of coccolithophores is paramount. In a multispecies comparison, spanning more than two orders of magnitude in terms of POC and PIC production rates, among Calcidiscus leptoporus, Coccolithus pelagicus subsp. braarudii, Emiliania huxleyi, Gephyrocapsa oceanica, and Scyphosphaera apsteinii, we found that cellular PIC : POC was a good predictor for a species{\textquoteright} OA sensitivity. This is likely related to the need for cellular pH homeostasis, which is challenged by the process of calcification producing protons internally, especially when seawater pH decreases in an OA scenario. With higher PIC : POC, species and strains being more sensitive to OA coccolithophores may shift toward less calcified varieties in the future.}, keywords = {RCC1130, RCC1141, RCC1168, RCC1198, RCC1200, RCC1323, RCC1334}, issn = {2378-2242}, doi = {10.1002/lol2.10105}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lol2.10105}, author = {Gafar, N. A. and Eyre, B. D. and Schulz, K. G.} } @article {bramucci_phaeobacter_2019, title = {Phaeobacter inhibens induces apoptosis-like programmed cell death in calcifying Emiliania huxleyi}, journal = {Scientific Reports}, volume = {9}, number = {1}, year = {2019}, note = {Number: 1 Publisher: Nature Publishing Group}, month = {mar}, pages = {1{\textendash}12}, abstract = {The model coccolithophore, Emiliania huxleyi, forms expansive blooms dominated by the calcifying cell type, which produce calcite scales called coccoliths. Blooms last several weeks, after which the calcified algal cells rapidly die, descending into the deep ocean. E. huxleyi bloom collapse is attributed to E. huxleyi viruses (EhVs) that infect and kill calcifying cells, while other E. huxleyi pathogens, such as bacteria belonging to the roseobacter clade, are overlooked. EhVs kill calcifying E. huxleyi by inducing production of bioactive viral-glycosphingolipids (vGSLs), which trigger algal programmed cell death (PCD). The roseobacter Phaeobacter inhibens was recently shown to interact with and kill the calcifying cell type of E. huxleyi, but the mechanism of algal death remains unelucidated. Here we demonstrate that P. inhibens kills calcifying E. huxleyi by inducing a highly specific type of PCD called apoptosis-like-PCD (AL-PCD). Host death can successfully be abolished in the presence of a pan-caspase inhibitor, which prevents the activation of caspase-like molecules. This finding differentiates P. inhibens and EhV pathogenesis of E. huxleyi, by demonstrating that bacterial-induced AL-PCD requires active caspase-like molecules, while the viral pathogen does not. This is the first demonstration of a bacterium inducing AL-PCD in an algal host as a killing mechanism.}, keywords = {RCC1216}, issn = {2045-2322}, doi = {10.1038/s41598-018-36847-6}, url = {http://www.nature.com/articles/s41598-018-36847-6}, author = {Bramucci, Anna R. and Case, Rebecca J.} } @article {Demory2019, title = {Picoeukaryotes of the Micromonas genus: sentinels of a warming ocean}, journal = {The ISME Journal}, volume = {13}, number = {1}, year = {2019}, note = {tex.ids= Demory2018 tex.mendeley-tags: RCC114,RCC1697,RCC1862,RCC2257,RCC2306,RCC299,RCC451,RCC497,RCC746,RCC829,RCC834 publisher: Nature Publishing Group}, month = {jan}, pages = {132{\textendash}146}, abstract = {Photosynthetic picoeukaryotesx in the genus Micromonas show among the widest latitudinal distributions on Earth, experiencing large thermal gradients from poles to tropics. Micromonas comprises at least four different species often found in sympatry. While such ubiquity might suggest a wide thermal niche, the temperature response of the different strains is still unexplored, leaving many questions as for their ecological success over such diverse ecosystems. Using combined experiments and theory, we characterize the thermal response of eleven Micromonas strains belonging to four species. We demonstrate that the variety of specific responses to temperature in the Micromonas genus makes this environmental factor an ideal marker to describe its global distribution and diversity. We then propose a diversity model for the genus Micromonas, which proves to be representative of the whole phytoplankton diversity. This prominent primary producer is therefore a sentinel organism of phytoplankton diversity at the global scale. We use the diversity within Micromonas to anticipate the potential impact of global warming on oceanic phytoplankton. We develop a dynamic, adaptive model and run forecast simulations, exploring a range of adaptation time scales, to probe the likely responses to climate change. Results stress how biodiversity erosion depends on the ability of organisms to adapt rapidly to temperature increase.}, keywords = {Biogeography, change ecology, Climate, microbial ecology, RCC114, RCC1697, RCC1862, RCC2257, RCC2306, RCC299, RCC451, RCC497, RCC746, RCC829, RCC834}, issn = {1751-7362}, doi = {10.1038/s41396-018-0248-0}, url = {http://www.nature.com/articles/s41396-018-0248-0}, author = {Demory, David and Baudoux, Anne-claire and Monier, Adam and Simon, Nathalie and Six, Christophe and Ge, Pei and Rigaut-jalabert, Fabienne and Marie, Dominique and Sciandra, Antoine and Bernard, Olivier and Rabouille, Sophie} } @article {Barton2019, title = {Quantifying the temperature dependence of growth rate in marine phytoplankton within and across species}, journal = {Limnology and Oceanography}, year = {2019}, note = {tex.mendeley-tags: RCC1303,RCC1512,RCC1731,RCC1773,RCC4221,RCC539,RCC6,RCC623,RCC626,RCC652,RCC653,RCC655,RCC834,RCC88}, abstract = {Abstract Models of marine biogeochemistry capture the effects of temperature on phytoplankton growth via the monotonic, exponential Eppley coefficient, without considering the physiological or evolutionary processes that underpin this emergent, across-species temperature response. Here, we investigated both the within- and across-species temperature dependence of growth rate for 18 species of marine phytoplankton. We found that the temperature dependence of growth rate derived across species was lower than the average temperature response within species. This finding supports a {\textquotedblleft}partial compensation{\textquotedblright} model of thermal adaptation and suggests that adaptation can partially compensate for the underlying thermodynamic effects of temperature on physiological rates observed within species. We also found that thermal tolerance traits (e.g. the optimum temperature for growth) systematically covaried with a host of key functional traits (e.g. cell size, elemental composition). Consequently, turnover in species composition in a warmer ocean, linked to interspecific variability in thermal tolerance traits, could be associated with major shifts in the functional trait composition of marine phytoplankton communities with far reaching implications for ecosystem functioning.}, keywords = {RCC1303, rcc1512, rcc1731, RCC1773, RCC4221, rcc539, RCC6, RCC623, RCC626, RCC652, RCC653, RCC655, RCC834, RCC88}, issn = {0024-3590}, doi = {10.1002/lno.11170}, author = {Barton, Samuel and Yvon-Durocher, Gabriel} } @article {LingeJohnsen2019, title = {Relationship between coccolith length and thickness in the coccolithophore species Emiliania huxleyi and Gephyrocapsa oceanica}, journal = {PLOS ONE}, volume = {14}, number = {8}, year = {2019}, note = {tex.mendeley-tags: RCC1210,RCC1223,RCC1232,RCC1824,RCC1843,RCC868}, month = {aug}, pages = {e0220725}, keywords = {rcc1210, RCC1223, RCC1232, rcc1824, rcc1843, rcc868}, issn = {1932-6203}, doi = {10.1371/journal.pone.0220725}, url = {http://dx.plos.org/10.1371/journal.pone.0220725}, author = {Linge Johnsen, Simen Alexander and Bollmann, J{\"o}rg and Gebuehr, Christina and Herrle, Jens O.}, editor = {Keller, David Peter} } @article {Gaignard2019, title = {Screening of marine microalgae: Investigation of new exopolysaccharide producers}, journal = {Algal Research}, volume = {44}, year = {2019}, note = {tex.ids= Gaignard2019a tex.mendeley-tags: RCC1084,RCC1196,RCC1504,RCC1714,RCC1774,RCC1786,RCC1863,RCC1978,RCC1983,RCC2035,RCC232,RCC2350,RCC2352,RCC2368,RCC2380,RCC2381,RCC2383,RCC2436,RCC2558,RCC2598,RCC2608,RCC2614,RCC2624,RCC2638,RCC269,RCC2696,RCC2703,RCC2932,RCC3069,RCC3072,RCC3092,RCC3093,RCC3436,RCC3649,RCC377,RCC4094,RCC4438,RCC4555,RCC4621,RCC4631,RCC4657,RCC76,RCC775,RCC821,RCC97 publisher: Elsevier}, month = {dec}, pages = {101711}, abstract = {Biopolymers, such as exopolysaccharides are widely exploited by industry as hydrocolloids (gelling, thickening agents) and biological agents (anti-inflammatory, anti-parasitic, antioxidant, etc.). In this study, 166 marine microalgae and cyanobacteria species have been screened in order to identify strains producing original exopolysaccharides. This screening allowed the highlighting of 45 positive strains. In a second time, the monosaccharide compositions from 20 EPS of them were determined by GC/MS and HPAEC-PAD. The results led to a discovery of 8 new genera of microalgae producing EPS, including polymers with a very original composition like richness in GlcA. Finally, a phylogenic tree has been contructed in order to assess the link between the phylogeny of microalgae and the global composition of their exopolymers, based on data obtained in this study and from the literature.}, keywords = {rcc1084, RCC1196, RCC1504, RCC1714, RCC1774, RCC1786, RCC1863, RCC1978, RCC1983, RCC2035, RCC232, RCC2350, RCC2352, RCC2368, rcc2380, RCC2381, RCC2383, RCC2436, RCC2558, RCC2598, RCC2608, RCC2614, RCC2624, RCC2638, RCC269, RCC2696, RCC2703, RCC2932, RCC3069, RCC3072, RCC3092, RCC3093, RCC3436, RCC3649, RCC377, RCC4094, RCC4438, RCC4555, RCC4621, RCC4631, RCC4657, RCC76, RCC775, RCC821, RCC97}, issn = {22119264}, doi = {10.1016/j.algal.2019.101711}, url = {https://www.sciencedirect.com/science/article/pii/S2211926419303261 https://linkinghub.elsevier.com/retrieve/pii/S2211926419303261}, author = {Gaignard, C. and Laroche, C. and Pierre, G. and Dubessay, P. and Delattre, C. and Gardarin, C. and Gourvil, P. and Probert, I. and Dubuffet, A. and Michaud, P.} } @article {Tsuboi2019, title = {Short-term changes in marine prokaryotic and eukaryotic microalgal communities exposed to the leachate of a seafloor hydrothermal sulfide}, journal = {Water, Air, \& Soil Pollution}, volume = {230}, year = {2019}, note = {tex.mendeley-tags: RCC,RCC1089,RCC262}, pages = {175}, abstract = {The effects of increased mining of seafloor massive sulfide deposits on marine ecosystems have not been characterized. In this study, the impact of leaching metals from a hydrothermal sulfide on photosynthetic protist and cyanobacterial communities in marine environments was investigated by amplicon analyses of small subunit rDNA (SSU rDNA) and rRNA (SSU rRNA). Seawater samples collected from the Iheya North region and Suruga Bay, Japan, were incubated with or without a leachate containing zinc, copper, cadmium, and manganese, of the actual seafloor hydrothermal sulfide from the Hakurei site in the Izena Hole region. The relative abundances of prasinophytes, diatom protists, and the cyanobacteria Synechococcus decreased substantially during incubation with leachate, indicating the vulnerability of these lineages to the leachate. Phylogenetic analysis based on the cyanobacterial phycocyanin cpcBA/rpcBA operon obtained from samples incubated with or without leachate indicated that the individual lineages of Synechococcus can determine sensitivity to heavy metals in different marine regions as well as particular clades and ecotypes.}, keywords = {rcc, RCC1089, RCC262}, doi = {10.1007/s11270-019-4224-8}, author = {Tsuboi, Shun and Yamaguchi, Haruyo and Fuchida, Shigeshi and Koshikawa, Hiroshi and Kawachi, Masanobu} } @article {Sanchez2019, title = {Simplified transformation of ostreococcus tauri using polyethylene glycol}, journal = {Genes}, volume = {10}, number = {5}, year = {2019}, note = {tex.mendeley-tags: RCC4221}, month = {may}, pages = {399}, abstract = {Ostreococcustauri is an easily cultured representative of unicellular algae (class Mamiellophyceae) that abound in oceans worldwide. Eight complete 13{\textendash}22 Mb genomes of phylogenetically divergent species within this class are available, and their DNA sequences are nearly always present in metagenomic data produced from marine samples. Here we describe a simplified and robust transformation protocol for the smallest of these algae (O. tauri). Polyethylene glycol (PEG) treatment was much more efficient than the previously described electroporation protocol. Short (2 min or less) incubation times in PEG gave {\textquestiondown}104 transformants per microgram DNA. The time of cell recovery after transformation could be reduced to a few hours, permitting the experiment to be done in a day rather than overnight as used in previous protocols. DNA was randomly inserted in the O. tauri genome. In our hands PEG was 20{\textendash}40-fold more efficient than electroporation for the transformation of O. tauri, and this improvement will facilitate mutagenesis of all of the dispensable genes present in the tiny O. tauri genome.}, keywords = {bioluminescence, Chlorophyta, Ecosystem, Gene Expression, luciferase, mamiellophyceae, Ostreococcus, picoeukaryote, plankton, Prasinophyte, promoter, RCC4221}, issn = {2073-4425}, doi = {10.3390/genes10050399}, url = {https://www.mdpi.com/2073-4425/10/5/399}, author = {Sanchez, Fr{\'e}d{\'e}ric and Geffroy, Sol{\`e}ne and Norest, Manon and Yau, Sheree and Moreau, Herv{\'e} and Grimsley, Nigel} } @article {Wilson2019, title = {Susceptibility of algae to Cr toxicity reveals contrasting metal management strategies}, journal = {Limnology and Oceanography}, volume = {64}, number = {5}, year = {2019}, note = {Publisher: John Wiley \& Sons, Ltd tex.mendeley-tags: RCC1,RCC1242,RCC4221,RCC950}, month = {sep}, pages = {2271{\textendash}2282}, abstract = {At the Paleozoic{\textendash}Mesozoic boundary, the dominance of marine eukaryotic algae shifted from the green (chlorophyll b) to the red (chlorophyll c) superfamily. Selection pressures caused by the bioavailability of trace metals associated with increasing oxygenation of the ocean may have played a key role in this algal revolution. From a scan of elemental compositions, a significant difference in the cellular Cr/P quota was found between the two superfamilies. Here, the different responses to high levels of Cr exposure reveal contrasting strategies for metal uptake and homeostasis in these algal lineages. At high Cr(VI) concentrations, red lineages experience growth inhibition through reduced photosynthetic capability, while green lineages are completely unaffected. Moreover, Cr(VI) has a more significant impact on the metallomes of red lineage algae, in which metal/P ratios increased with increasing Cr(VI) concentration for many trace elements. Green algae have higher specificity transporters to prevent Cr(VI) from entering the cell, and more specific intracellular stores of Cr within the membrane fraction than the red algae, which accumulate more Cr mistakenly in the cytosol fraction via lower affinity transport mechanisms. Green algal approaches require greater nutrient investments in the more numerous transport proteins required and management of specific metals, a strategy better adapted to the resource-rich coastal waters. By contrast, the red algae are nutrient-efficient with fewer and less discriminate metal transporters, which can be fast and better adapted in the oligotrophic, oxygenated open ocean, which has prevailed since the deepening of the oxygen minimum zones at the start of the Mesozoic era.}, keywords = {RCC1, RCC1242, RCC4221, RCC950}, issn = {0024-3590}, doi = {10.1002/lno.11183}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lno.11183}, author = {Wilson, Will and Zhang, Qiong and Rickaby, Rosalind E. M.} } @article {Kashiyama2019, title = {Taming chlorophylls by early eukaryotes underpinned algal interactions and the diversification of the eukaryotes on the oxygenated Earth}, journal = {The ISME Journal}, year = {2019}, note = {Publisher: Springer US tex.mendeley-tags: RCC164,RCC22,RCC24,RCC375,RCC916}, month = {feb}, pages = {1}, abstract = {Extant eukaryote ecology is primarily sustained by oxygenic photosynthesis, in which chlorophylls play essential roles. The exceptional photosensitivity of chlorophylls allows them to harvest solar energy for photosynthesis, but on the other hand, they also generate cytotoxic reactive oxygen species. A risk of such phototoxicity of the chlorophyll must become particularly prominent upon dynamic cellular interactions that potentially disrupt the mechanisms that are designed to quench photoexcited chlorophylls in the phototrophic cells. Extensive examination of a wide variety of phagotrophic, parasitic, and phototrophic microeukaryotes demonstrates that a catabolic process that converts chlorophylls into nonphotosensitive 132,173-cyclopheophorbide enols (CPEs) is phylogenetically ubiquitous among extant eukaryotes. The accumulation of CPEs is identified in phagotrophic algivores belonging to virtually all major eukaryotic assemblages with the exception of Archaeplastida, in which no algivorous species have been reported. In addition, accumulation of CPEs is revealed to be common among phototrophic microeukaryotes (i.e., microalgae) along with dismantling of their secondary chloroplasts. Thus, we infer that CPE-accumulating chlorophyll catabolism (CACC) primarily evolved among algivorous microeukaryotes to detoxify chlorophylls in an early stage of their evolution. Subsequently, it also underpinned photosynthetic endosymbiosis by securing close interactions with photosynthetic machinery containing abundant chlorophylls, which led to the acquisition of secondary chloroplasts. Our results strongly suggest that CACC, which allowed the consumption of oxygenic primary producers, ultimately permitted the successful radiation of the eukaryotes throughout and after the late Proterozoic global oxygenation.}, keywords = {Biochemistry, Biogeochemistry, Cellular microbiology, microbial ecology, RCC164, RCC22, RCC24, RCC375, RCC916}, issn = {1751-7362}, doi = {10.1038/s41396-019-0377-0}, url = {http://www.nature.com/articles/s41396-019-0377-0}, author = {Kashiyama, Yuichiro and Yokoyama, Akiko and Shiratori, Takashi and Hess, Sebastian and Not, Fabrice and Bachy, Charles and Gutierrez-Rodriguez, Andres and Kawahara, Jun and Suzaki, Toshinobu and Nakazawa, Masami and Ishikawa, Takahiro and Maruyama, Moe and Wang, Mengyun and Chen, Man and Gong, Yingchun and Seto, Kensuke and Kagami, Maiko and Hamamoto, Yoko and Honda, Daiske and Umetani, Takahiro and Shihongi, Akira and Kayama, Motoki and Matsuda, Toshiki and Taira, Junya and Yabuki, Akinori and Tsuchiya, Masashi and Hirakawa, Yoshihisa and Kawaguchi, Akane and Nomura, Mami and Nakamura, Atsushi and Namba, Noriaki and Matsumoto, Mitsufumi and Tanaka, Tsuyoshi and Yoshino, Tomoko and Higuchi, Rina and Yamamoto, Akihiro and Maruyama, Tadanobu and Yamaguchi, Aika and Uzuka, Akihiro and Miyagishima, Shinya and Tanifuji, Goro and Kawachi, Masanobu and Kinoshita, Yusuke and Tamiaki, Hitoshi} } @article {Turmel2019, title = {Tracing the evolution of the plastome and mitogenome in the chloropicophyceae uncovered convergent tRNA gene losses and a variant plastid genetic code}, journal = {Genome Biology and Evolution}, volume = {in press}, year = {2019}, note = {tex.mendeley-tags: RCC15,RCC1871,RCC2335,RCC2339,RCC287,RCC3374,RCC3402,RCC4434,RCC4572,RCC4656,RCC696,RCC856,RCC998,RCC999}, month = {apr}, keywords = {RCC15, RCC1871, RCC2335, RCC2339, RCC287, RCC3374, RCC3402, RCC4434, RCC4572, RCC4656, RCC696, RCC856, RCC998, RCC999}, issn = {1759-6653}, doi = {10.1093/gbe/evz074}, url = {https://www.biorxiv.org/content/10.1101/530998v1 https://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evz074/5425330}, author = {Turmel, Monique and dos Santos, Adriana Lopes and Otis, Christian and Sergerie, Roxanne and Lemieux, Claude}, editor = {Archibald, John} } @article {Liu2019, title = {Transcriptome of thalassicolla nucleata holobiont reveals details of a radiolarian symbiotic relationship}, journal = {Frontiers in Marine Science}, volume = {6}, number = {June}, year = {2019}, note = {tex.mendeley-tags: RCC3387}, month = {jun}, pages = {1{\textendash}11}, keywords = {Brandtodinium, holobiont, photosymbiosis, radiolarian, RCC3387, Transcriptome}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00284}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00284/full}, author = {Liu, Zhenfeng and Mesrop, Lisa Y. and Hu, Sarah K. and Caron, David A.} } @article {Bouget2019, title = {Transient transformation of ostreococcus species (OTTH595, RCC809 and RCC802) and bathycoccus}, year = {2019}, note = {Publication Title: protocols.io tex.mendeley-tags: RCC802,RCC809}, keywords = {RCC802, RCC809}, doi = {10.17504/protocols.io.83uhynw}, url = {https://www.protocols.io/view/transient-transformation-of-ostreococcus-species-o-83uhynw}, author = {Bouget, Fran{\c c}ois Yves} } @article {Breton2019, title = {Unveiling membrane thermoregulation strategies in marine picocyanobacteria}, journal = {New Phytologist}, number = {July}, year = {2019}, note = {ISBN: 0000000244022 tex.mendeley-tags: RCC2374,RCC2385,RCC515,RCC539}, month = {oct}, pages = {nph.16239}, keywords = {RCC2374, RCC2385, RCC515, rcc539}, issn = {0028-646X}, doi = {10.1111/nph.16239}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.16239}, author = {Breton, Sol{\`e}ne and Jouhet, Juliette and Guyet, Ulysse and Gros, Val{\'e}rie and Pittera, Justine and Demory, David and Partensky, Fr{\'e}d{\'e}ric and Dor{\'e}, Hugo and Ratin, Morgane and Mar{\'e}chal, {\'E}ric and Nguyen, Ngoc An and Garczarek, Laurence and Six, Christophe} } @article {Pierre2019, title = {What is in store for EPS microalgae in the next decade?}, journal = {Molecules}, volume = {24}, number = {23}, year = {2019}, month = {nov}, pages = {4296}, abstract = {Microalgae and their metabolites have been an El Dorado since the turn of the 21st century. Many scientific works and industrial exploitations have thus been set up. These developments have often highlighted the need to intensify the processes for biomass production in photo-autotrophy and exploit all the microalgae value including ExoPolySaccharides (EPS). Indeed, the bottlenecks limiting the development of low value products from microalgae are not only linked to biology but also to biological engineering problems including harvesting, recycling of culture media, photoproduction, and biorefinery. Even respecting the so-called {\textquotedblleft}Biorefinery Concept{\textquotedblright}, few applications had a chance to emerge and survive on the market. Thus, exploiting EPS from microalgae for industrial applications in some low-value markets such as food is probably not a mature proposition considering the competitiveness of polysaccharides from terrestrial plants, macroalgae, and bacteria. However, it does not imply drawing a line on their uses but rather {\textquotedblleft}thinking them{\textquotedblright} differently. This review provides insights into microalgae, EPS, and their exploitation. Perspectives on issues affecting the future of EPS microalgae are also addressed with a critical point of view.}, keywords = {application, eps, exopolysaccharides, market, Microalgae}, issn = {1420-3049}, doi = {10.3390/molecules24234296}, url = {https://www.mdpi.com/1420-3049/24/23/4296}, author = {Pierre, Guillaume and Delattre, C{\'e}dric and Dubessay, Pascal and Jubeau, S{\'e}bastien and Vialleix, Carole and Cadoret, Jean-Paul and Probert, Ian and Michaud, Philippe} } @article {Beuvier2019, title = {X-ray nanotomography of coccolithophores reveals that coccolith mass and segment number correlate with grid size}, journal = {Nature Communications}, volume = {10}, number = {1}, year = {2019}, note = {Publisher: Springer US tex.mendeley-tags: RCC1212,RCC1216,RCC1314,RCC3370,RCC4032,RCC4036}, month = {dec}, pages = {751}, abstract = {Coccolithophores of the No{\"e}laerhabdaceae family are covered by imbricated coccoliths, each composed of multiple calcite crystals radially distributed around the periphery of a grid. The factors that determine coccolith size remain obscure. Here, we used synchrotron-based three-dimensional Coherent X-ray Diffraction Imaging to study coccoliths of 7 species of Gephyrocapsa, Emiliania and Reticulofenestra with a resolution close to 30 nm. Segmentation of 45 coccoliths revealed remarkable size, mass and segment number variations, even within single coccospheres. In particular, we observed that coccolith mass correlates with grid perimeter which scales linearly with crystal number. Our results indirectly support the idea that coccolith mass is determined in the coccolith vesicle by the size of the organic base plate scale (OBPS) around which R-unit nucleation occurs every 110{\textendash}120 nm. The curvation of coccoliths allows inference of a positive correlation between cell nucleus, OBPS and coccolith sizes.}, keywords = {Biomaterials, Marine biology, rcc1212, RCC1216, RCC1314, RCC3370, RCC4032, RCC4036}, issn = {2041-1723}, doi = {10.1038/s41467-019-08635-x}, url = {http://www.nature.com/articles/s41467-019-08635-x}, author = {Beuvier, T. and Probert, I. and Beaufort, L. and Such{\'e}ras-Marx, B. and Chushkin, Y. and Zontone, F. and Gibaud, A.} } @article {Cheng2018, title = {10KP: A phylodiverse genome sequencing plan}, journal = {GigaScience}, volume = {7}, number = {3}, year = {2018}, pages = {1{\textendash}9}, keywords = {10kp, 12 february 2018, 2018, 4, accepted, access article distributed under, and reproduction in any, attribution license, biodiversity, by, c the author, creative commons, creativecommons, Distribution, genome sequencing, genomics, http, licenses, medium, mgiseq, open community, org, phylogenomics, PLANTS, press, published by oxford university, received, s, samples, the terms of the, this is an open, which permits unrestricted reuse}, issn = {2047-217X}, doi = {10.1093/gigascience/giy013}, url = {https://academic.oup.com/gigascience/article/7/3/1/4880447}, author = {Cheng, Shifeng and Melkonian, Michael and Smith, Stephen A and Brockington, Samuel and Archibald, John M and Delaux, Pierre-Marc and Li, Fay-Wei and Melkonian, Barbara and Mavrodiev, Evgeny V and Sun, Wenjing and Fu, Yuan and Yang, Huanming and Soltis, Douglas E and Graham, Sean W and Soltis, Pamela S and Liu, Xin and Xu, Xun and Wong, Gane Ka-Shu} } @article {Meng2018, title = {Analysis of the genomic basis of functional diversity in dinoflagellates using a transcriptome-based sequence similarity network}, journal = {Molecular Ecology}, year = {2018}, note = {tex.mendeley-tags: RCC1491,RCC1516,RCC3387,RCC3468,RCC3507}, pages = {0{\textendash}2}, abstract = {Dinoflagellates are one of the most abundant and functionally diverse groups of eukaryotes. Despite an overall scarcity of genomic information for dinoflagellates, constantly emerging high-throughput sequencing resources can be used to characterize and compare these organisms. We assembled de novo and processed 46 dinoflagellate transcriptomes and used a sequence similarity network (SSN) to compare the underlying genomic basis of functional features within the group. This approach constitutes the most comprehensive picture to date of the genomic potential of dinoflagellates. A core predicted proteome composed of 252 connected components (CCs) of putative conserved protein domains (pCDs) was identified. Of these, 206 were novel and 16 lacked any functional annotation in public databases. Integration of functional information in our network analyses allowed investigation of pCDs specifically associated to functional traits. With respect to toxicity, sequences homologous to those of proteins found in species with toxicity potential (e.g. sxtA4 and sxtG) were not specific to known toxin-producing species. Although not fully specific to symbiosis, the most represented functions associated with proteins involved in the symbiotic trait were related to membrane processes and ion transport. Overall, our SSN approach led to identification of 45,207 and 90,794 specific and constitutive pCDs of respectively the toxic and symbiotic species represented in our analyses. Of these, 56\% and 57\% respectively (i.e. 25,393 and 52,193 pCDs) completely lacked annotation in public databases. This stresses the extent of our lack of knowledge, while emphasizing the potential of SSNs to identify candidate pCDs for further functional genomic characterization. This article is protected by copyright. All rights reserved.}, keywords = {Genomics/Proteomics, Microbial Biology, Molecular Evolution, Protists, rcc1491, RCC1516, RCC3387, rcc3468, rcc3507, transcriptomics}, issn = {09621083}, doi = {10.1111/mec.14579}, url = {http://www.ncbi.nlm.nih.gov/pubmed/29624751\%0Ahttp://doi.wiley.com/10.1111/mec.14579}, author = {Meng, Arnaud and Corre, Erwan and Probert, Ian and Gutierrez-Rodriguez, Andres and Siano, Raffaele and Annamale, Anita and Alberti, Adriana and Da Silva, Corinne and Wincker, Patrick and Le Crom, St{\'e}phane and Not, Fabrice and Bittner, Lucie} } @article {Crenn2018, title = {Bacterial epibiotic communities of ubiquitous and abundant marine diatoms are distinct in short- and long-term associations}, journal = {Frontiers in Microbiology}, volume = {9}, number = {December}, year = {2018}, note = {tex.mendeley-tags: 2018,RCC2560,RCC2565,rcc}, pages = {1{\textendash}12}, abstract = {Interactions between phytoplankton and bacteria play a central role in mediatingbiogeochemical cycling and food web structure in the ocean. The cosmopolitan diatomsThalassiosiraandChaetocerosoften dominate phytoplankton communities in marinesystems. Past studies of diatom-bacterial associations have employed community-level methods and culture-based or natural diatom populations. Although bacterialassemblages attached to individual diatoms represents tight associations little is knownon their makeup or interactions. Here, we examined the epibiotic bacteria of 436Thalassiosiraand 329Chaetocerossingle cells isolated from natural samples andcollection cultures, regarded here as short- and long-term associations, respectively.Epibiotic microbiota of single diatom hosts was analyzed by cultivation and by cloning-sequencing of 16S rRNA genes obtained from whole-genome amplification products.The prevalence of epibiotic bacteria was higher in cultures and dependent of the hostspecies. Culture approaches demonstrated that both diatoms carry distinct bacterialcommunities in short- and long-term associations. Bacterial epibonts, commonlyassociated with phytoplankton, were repeatedly isolated from cells of diatom collectioncultures but were not recovered from environmental cells. Our results suggest thatin controlled laboratory culture conditions bacterial{\textendash}diatom and bacterial{\textendash}bacterialinteractions select for a simplified, but specific, epibiotic microbiota shaped and adaptedfor long-term associations.}, keywords = {2018, Chaetoceros, diatoms, diversity, heterotrophic bacteria, interactions, microbiome, rcc, RCC2560, RCC2565, Thalassiosira, Western English Channel}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.02879}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2018.02879/full}, author = {Crenn, Klervi and Duffieux, Delphine and Jeanthon, Christian} } @article {Annunziata2018, title = {A bHLH-PAS protein regulates light-dependent rhythmic processes in the marine diatom Phaeodactylum tricornutum}, journal = {bioRxiv}, year = {2018}, note = {tex.mendeley-tags: RCC2967}, pages = {271445}, abstract = {Periodic light dark cycles govern the timing of basic biological processes in organisms inhabiting land as well as the sea, where life evolved. Although prominent marine phytoplanktonic organisms such as diatoms show robust diurnal rhythms in growth, cell cycle and gene expression, the molecular bases controlling these processes are still obscure. By exploring the regulatory landscape of diatom diurnal rhythms, we here unveil the key function of a Phaeodactylum tricornutum bHLH-PAS protein, named Pt bHLH1a, in the regulation of light-dependent rhythms. Peak expression of Pt bHLH1a mRNA occurs at the end of the light period and it is adjusted to photoperiod changes. Ectopic over-expression of Pt bHLH1a results in lines with altered cell division and gene expression and showing a phase shift in diurnal responses, compared to the wild-type cells. Reduced oscillations in gene expression are also observed in continuous darkness, showing that the regulation of rhythmicity by Pt bHLH1a is not directly dependent on light inputs and cell division. Pt bHLH1a orthologs are widespread in both pennate and centric diatom genomes, hinting at a common function in many species. This study adds new elements to understand diatom biology and ecology and offers new perspectives to elucidate timekeeping mechanisms in marine organisms belonging to a major, but still underinvestigated branch of the tree of life.}, keywords = {RCC2967}, doi = {10.1101/271445}, url = {https://www.biorxiv.org/content/early/2018/02/25/271445}, author = {Annunziata, Rossella and Ritter, Andr{\'e}s and Fortunato, Antonio Emidio and Cheminant-Navarro, Soizic and Agier, Nicolas and Huysman, Marie J. J. and Winge, Per and Bones, Atle and Bouget, Fran{\c c}ois-Yves and Lagomarsino, Marco Cosentino and Bouly, Jean Pierre and Falciatore, Angela} } @article {Kuwata2018, title = {Bolidophyceae, a sister picoplanktonic group of diatoms {\textendash} a review}, journal = {Frontiers in Marine Science}, volume = {5}, year = {2018}, note = {tex.mendeley-tags: RCC1657,RCC201,RCC205,RCC206,RCC212,RCC239}, month = {oct}, pages = {370}, keywords = {RCC1657, RCC201, RCC205, RCC206, rcc212, RCC239}, issn = {2296-7745}, doi = {10.3389/fmars.2018.00370}, url = {https://www.frontiersin.org/article/10.3389/fmars.2018.00370/full}, author = {Kuwata, Akira and Yamada, Kazumasa and Ichinomiya, Mutsuo and Yoshikawa, Shinya and Tragin, Margot and Vaulot, Daniel and Lopes dos Santos, Adriana} } @article {Fox2018, title = {Calcein staining as a tool to investigate coccolithophore calcification}, journal = {Frontiers in Marine Science}, volume = {5}, number = {September}, year = {2018}, note = {tex.mendeley-tags: RCC 1461,RCC 3777,RCC1130,RCC1303,RCC1456}, abstract = {This brief paper summarizes the literature on academic accommodations for students with psychiatric disabilities. A definition of psychiatric disability precedes a brief summary of the following specific psychiatric diagnoses: depression, bipolar affective disorder; borderline personality disorder; schizophrenia; and anxiety disorders. Also noted are behavior or personality disorders specifically excluded from coverage under the Americans with Disabilities Act. Functional limitations of this population that may affect academic performance are then listed and defined. Among these are medication side effects, sustaining concentration, maintaining stamina, interacting with others, responding to negative feedback, responding to change, and severe test anxiety. Examples of appropriate instructional strategies are followed by a discussion of reasonable accommodations to provide these students with equal access to the curriculum. Examples are then given of classroom accommodations, examination accommodations, and assignment accommodations. Characteristics of accommodations that are not reasonable are also listed. The paper concludes with a resource list including Web site and contact information for the DO-IT (Disabilities, Opportunities, Internetworking, and Technology) Project. (DB)}, keywords = {bet hedging, calcein, Calcification, coccolith, coccolithophore, flow cytometry, haptophyte, RCC1130, RCC1303, RCC1456, RCC1461, RCC3777, secretion}, issn = {2296-7745}, doi = {10.3389/fmars.2018.00326}, url = {https://www.frontiersin.org/article/10.3389/fmars.2018.00326/full}, author = {Fox, Emily and Meyer, Erin and Panasiak, Natalie and Taylor, Alison R.} } @article {McQuaid2018, title = {Carbonate-sensitive phytotransferrin controls high-affinity iron uptake in diatoms}, journal = {Nature}, volume = {555}, number = {7697}, year = {2018}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: RCC2967}, month = {mar}, pages = {534{\textendash}537}, abstract = {Iron is an essential nutrient for photosynthetic plankton (phytoplankton), but owing to its low solubility in vast areas of the ocean the concentration of this metal is low, limiting the growth of the phytoplankton. Andrew Allen and co-workers show that the phytoplankton Phaeodactylum tricornutum has developed a specific iron acquisition mechanism that relies on activity of the ISIP2A protein. ISIP2A represents a functional analogue of transferrin{\textemdash}a metazoan protein that binds iron with high affinity{\textemdash}as both proteins use similar iron binding, internalization and release mechanisms, suggesting their independent and convergent evolution. Both proteins bind iron through a synergistic interaction of ferric iron and CO32-, and because ocean acidification decreases CO32- concentration it may also decrease phytoplankton iron uptake and growth.}, keywords = {RCC2967}, issn = {0028-0836}, doi = {10.1038/nature25982}, url = {http://dx.doi.org/10.1038/nature25982 http://www.nature.com/doifinder/10.1038/nature25982}, author = {McQuaid, Jeffrey B. and Kustka, Adam B. and Obornik, Miroslav and Horak, Ales and McCrow, John P. and Karas, Bogumil J. and Zheng, Hong and Kindeberg, Theodor and Andersson, Andreas J. and Barbeau, Katherine A. and Allen, Andrew E.} } @article {Paerl2018, title = {Carboxythiazole is a key microbial nutrient currency and critical component of thiamin biosynthesis}, journal = {Scientific Reports}, volume = {8}, number = {1}, year = {2018}, note = {Publisher: Springer US tex.mendeley-tags: RCC4222,RCC745}, pages = {5940}, keywords = {RCC4222, RCC745}, issn = {2045-2322}, doi = {10.1038/s41598-018-24321-2}, url = {http://www.nature.com/articles/s41598-018-24321-2}, author = {Paerl, Ryan W. and Bertrand, Erin M. and Rowland, Elden and Schatt, Phillippe and Mehiri, Mohamed and Niehaus, Thomas D. and Hanson, Andrew D. and Riemann, Lasse and Yves-Bouget, Francois} } @article {Guyon2018, title = {Comparative analysis of culture conditions for the optimization of carotenoid production in several strains of the picoeukaryote ostreococcus}, journal = {Marine Drugs}, volume = {16}, number = {3}, year = {2018}, note = {tex.mendeley-tags: 2018,RCC745,RCC802,RCC809,rcc}, pages = {76}, abstract = {Microalgae are promising sources for the sustainable production of compounds of interest for biotechnologies. Compared to higher plants, microalgae have a faster growth rate and can be grown in industrial photobioreactors. The microalgae biomass contains specific metabolites of high added value for biotechnology such as lipids, polysaccharides or carotenoid pigments. Studying carotenogenesis is important for deciphering the mechanisms of adaptation to stress tolerance as well as for biotechnological production. In recent years, the picoeukaryote Ostreococcus tauri has emerged as a model organism thanks to the development of powerful genetic tools. Several strains of Ostreococcus isolated from different environments have been characterized with respect to light response or iron requirement. We have compared the carotenoid contents and growth rates of strains of Ostreococcus (OTTH595, RCC802 and RCC809) under a wide range of light, salinity and temperature conditions. Carotenoid profiles and productivities varied in a strain-specific and stress-dependent manner. Our results also illustrate that phylogenetically related microalgal strains originating from different ecological niches present specific interests for the production of specific molecules under controlled culture conditions.}, keywords = {2018, carotenoids, GROWTH RATE, Light, Ostreococcus, rcc, RCC745, RCC802, RCC809, salinity, temperature}, issn = {1660-3397}, doi = {10.3390/md16030076}, url = {http://www.mdpi.com/1660-3397/16/3/76}, author = {Guyon, Jean-baptiste and Schatt, Philippe and Lozano, Jean-Claude and Liennard, Marion and Bouget, Fran{\c c}ois-Yves} } @article {Farhat2018, title = {Comparative time-scale gene expression analysis highlights the infection processes of two amoebophrya strains}, journal = {Frontiers in Microbiology}, volume = {9}, number = {October}, year = {2018}, note = {tex.mendeley-tags: RCC1627,RCC3596,RCC4383,RCC4398}, month = {oct}, pages = {1{\textendash}19}, keywords = {amoebophrya, Dinoflagellates, Gene Expression, infection, oxidative stress response, parasite, plankton, RCC1627, RCC3596, RCC4383, RCC4398, syndiniales}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.02251}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2018.02251/full}, author = {Farhat, Sarah and Florent, Isabelle and Noel, Benjamin and Kayal, Ehsan and Da Silva, Corinne and Bigeard, Estelle and Alberti, Adriana and Labadie, Karine and Corre, Erwan and Aury, Jean-Marc and Rombauts, Stephane and Wincker, Patrick and Guillou, Laure and Porcel, Betina M.} } @article {Kenworthy2018, title = {Compared stress tolerance to short-term exposure in native and invasive tunicates from the NE Atlantic: when the invader performs better}, journal = {Marine Biology}, volume = {165}, number = {10}, year = {2018}, note = {tex.mendeley-tags: RCC179}, pages = {164}, abstract = {{The combined impact of invasive species and climate change threatens natural systems worldwide, often facilitating the expansion of harmful invasive species. It is imperative to understand the mechanisms behind why species become invasive and widespread. Traditionally, it is thought that invasive species have greater tolerances to a wider array of environmental conditions than natives. We, therefore, tested the hypothesis that invasive species are more tolerant to the effects of short-term exposure to temperature and salinity stress. Using unifactorial experiments, we compared the tolerances of two common fouling NE Atlantic ascidians, the native Ciona intestinalis and the invasive Styela clava, to increased temperature and decreased salinity. We measured lethal and behavioural responses affecting 50\% of populations to give an indication of the tolerance limits for temperature (LT50) and salinity (EC50), and respiration rate to give an indication of the change in metabolic response. The invasive S. clava was more tolerant to increased stress (LT50 = 29.5 {\textdegree}C}, keywords = {RCC179}, issn = {1432-1793}, doi = {10.1007/s00227-018-3420-1}, url = {https://doi.org/10.1007/s00227-018-3420-1}, author = {Kenworthy, Joseph M and Davoult, Dominique and Lejeusne, Christophe} } @article {Partensky2018, title = {Comparison of photosynthetic performances of marine picocyanobacteria with different configurations of the oxygen-evolving complex}, journal = {Photosynthesis Research}, volume = {138}, number = {1}, year = {2018}, note = {tex.mendeley-tags: RCC752}, pages = {57{\textendash}71}, abstract = {The extrinsic PsbU and PsbV proteins are known to play a critical role in stabilizing the Mn4CaO5 cluster of the PSII oxygen-evolving complex (OEC). However, most isolates of the marine cyanobacterium Prochlorococcus naturally miss these proteins, even though they have kept the main OEC protein, PsbO. A structural homology model of the PSII of such a natural deletion mutant strain (P. marinus MED4) did not reveal any obvious compensation mechanism for this lack. To assess the physiological consequences of this unusual OEC, we compared oxygen evolution between Prochlorococcus strains missing psbU and psbV (PCC 9511 and SS120) and two marine strains possessing these genes (Prochlorococcus sp. MIT9313 and Synechococcus sp. WH7803). While the low light-adapted strain SS120 exhibited the lowest maximal O2 evolution rates (Pmax per divinyl-chlorophyll a, per cell or per photosystem II) of all four strains, the high light-adapted strain PCC 9511 displayed even higher PChlmax and PPSIImax at high irradiance than Synechococcus sp. WH7803. Furthermore, thermoluminescence glow curves did not show any alteration in the B-band shape or peak position that could be related to the lack of these extrinsic proteins. This suggests an efficient functional adaptation of the OEC in these natural deletion mutants, in which PsbO alone is seemingly sufficient to ensure proper oxygen evolution. Our study also showed that Prochlorococcus strains exhibit negative net O2 evolution rates at the low irradiances encountered in minimum oxygen zones, possibly explaining the very low O2 concentrations measured in these environments, where Prochlorococcus is the dominant oxyphototroph.}, keywords = {rcc752}, issn = {1573-5079}, doi = {10.1007/s11120-018-0539-3}, url = {https://doi.org/10.1007/s11120-018-0539-3}, author = {Partensky, Fr{\'e}d{\'e}ric and Mella-Flores, Daniella and Six, Christophe and Garczarek, Laurence and Czjzek, Mirjam and Marie, Dominique and Kotabov{\'a}, Eva and Felcmanov{\'a}, Kristina and Pr{\'a}{\v s}il, Ond{\v r}ej} } @article {Engesmo2018, title = {Development of a qPCR assay to detect and quantify ichthyotoxic flagellates along the Norwegian coast, and the first Norwegian record of Fibrocapsa japonica (Raphidophyceae)}, journal = {Harmful Algae}, volume = {75}, year = {2018}, note = {Publisher: Elsevier B.V. tex.mendeley-tags: RCC1501,RCC1502}, pages = {105{\textendash}117}, abstract = {Blooms of ichthyotoxic microalgae pose a great challenge to the aquaculture industry world-wide, and there is a need for fast and specific methods for their detection and quantification in monitoring programs. In this study, quantitative real-time PCR (qPCR) assays for the detection and enumeration of three ichthyotoxic flagellates: the dinoflagellate Karenia mikimotoi (Miyake \& Kominami ex Oda) Hansen \& Moestrup and the two raphidophytes Heterosigma akashiwo (Hada) Hada ex Hara \& Chihara and Fibrocapsa japonica Toriumi \& Takano were developed. Further, a previously published qPCR assay for the dinoflagellate Karlodinium veneficum (Ballantine) Larsen was used. Monthly samples collected for three years (Aug 2009{\textendash}Jun 2012) in outer Oslofjorden, Norway were analysed, and the results compared with light microscopy cell counts. The results indicate a higher sensitivity and a lower detection limit (down to 1 cell L-1) for both qPCR assays. Qualitative and semi-quantitative results were further compared with those obtained by environmental 454 high throughput sequencing (HTS, metabarcoding) and scanning electron microscopy (SEM) examination from the same samplings. All four species were detected by qPCR and HTS and/or SEM in outer Oslofjorden (Aug 2009{\textendash}Jun 2012); Karlodinium veneficum was present year-round, whereas Karenia mikimotoi, Heterosigma akashiwo and Fibrocapsa japonica appeared mainly during the autumn in all three years. This is the first observation of Fibrocapsa japonica in Norwegian coastal waters. This species has previously been recorded off the Swedish west coast and German Bight, which may suggest a northward dispersal.}, keywords = {454 high throughput environmental sequencing, Heterosigma akashiwo, Karenia mikimotoi, Karlodinium veneficum, Molecular monitoring, rcc1501, rcc1502, RDNA, SEM}, issn = {15689883}, doi = {10.1016/j.hal.2018.04.007}, url = {https://doi.org/10.1016/j.hal.2018.04.007}, author = {Engesmo, Anette and Strand, David and Gran-Stadnicze{\~n}ko, Sandra and Edvardsen, Bente and Medlin, Linda K. and Eikrem, Wenche} } @article {Dadaglio2018, title = {Differential responses of bacteria to diatom-derived dissolved organic matter in the Arctic Ocean}, journal = {Aquatic Microbial Ecology}, volume = {82}, number = {1}, year = {2018}, note = {tex.mendeley-tags: 2018,rcc}, pages = {59{\textendash}72}, abstract = {ABSTRACT: The Arctic sea ice cover is undergoing an unprecedented decline due to climate change. This loss may result in the earlier start of ice algae blooms and more intense phytoplankton blooms, leading to higher concentrations of dissolved organic matter (DOM) derived from primary production. We investigated the response of early summer Arctic bacterial communities to the addition of Arctic diatom-derived DOM through biodegradation experiments in Baffin Bay. DOM produced by the planktonic diatom Chaetoceros neogracilis and the sea ice diatom Fragilariopsis cylindrus was added to seawater from 3 stations with different ice cover (2 ice zones and 1 open water zone) for 12 d. At the 3 stations, the addition of inorganic nutrients (PO4 and NO3) was not sufficient to stimulate bacterial growth compared to the controls, suggesting that bacteria were mainly limited by organic carbon. The addition of DOM from C. neogracilis stimulated bacterial abundance and production, with a more pronounced response in the ice zone compared to the open water zone. The enhanced bacterial metabolism was accompanied by changes in the bacterial community composition determined by 16S rRNA sequencing, driven by operational taxonomic units (OTUs) related to Pseudoalteromonas and Polaribacter that increased in relative abundance with DOM addition. Moreover, in the ice zone, DOM from C. neogracilis induced a priming effect on the bacterial utilization of ambient DOM. Our findings suggest that phytoplankton blooms, through the production of labile organic matter, will strongly affect bacterial heterotrophic activity, composition and dissolved organic carbon cycling in the Arctic Ocean.}, keywords = {2018, rcc}, doi = {10.3354/ame01883}, url = {https://www.int-res.com/abstracts/ame/v82/n1/p59-72}, author = {Dadaglio, L and Dinasquet, J and Obernosterer, I and Joux, F} } @article {Kazamia2018, title = {Endocytosis-mediated siderophore uptake as a strategy for Fe acquisition in diatoms}, journal = {Science Advances}, volume = {4}, number = {5}, year = {2018}, note = {tex.mendeley-tags: RCC2967}, month = {may}, pages = {eaar4536}, keywords = {RCC2967}, issn = {2375-2548}, doi = {10.1126/sciadv.aar4536}, url = {http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aar4536}, author = {Kazamia, Elena and Sutak, Robert and Paz-Yepes, Javier and Dorrell, Richard G and Vieira, Fabio Rocha Jimenez and Mach, Jan and Morrissey, Joe and Leon, S{\'e}bastien and Lam, France and Pelletier, Eric and Camadro, Jean-michel and Bowler, Chris and Lesuisse, Emmanuel} } @article {Garcia2018, title = {High variability in cellular stoichiometry of carbon, nitrogen, and phosphorus within classes of marine eukaryotic phytoplankton under sufficient nutrient conditions}, journal = {Frontiers in Microbiology}, volume = {9}, number = {March}, year = {2018}, note = {tex.mendeley-tags: RCC103,RCC1242,RCC1562,RCC4023,RCC449,RCC931}, pages = {1{\textendash}10}, abstract = {Current hypotheses suggest that cellular elemental stoichiometry of marine eukaryotic phytoplankton such as the ratios of cellular carbon:nitrogen:phosphorus (C:N:P) vary between phylogenetic groups based traits like evolutionary history and cell size. To investigate how phylogenetic structure, cell volume, growth rate and temperature interact to affect the cellular elemental stoichiometry of marine eukaryotic phytoplankton, we examined the C:N:P composition in 30 isolates across 7 classes of marine phytoplankton that were grown with a sufficient supply of nutrients with nitrate as the nitrogen source. The isolates covered a wide range in cell volume (5 orders of magnitude), growth rate ({\textexclamdown}0.01-0.9 d-1), and habitat temperature (2-24{\textdegree}C). Our analysis indicates that C:N:P is highly variable, with statistical model residuals accounting for over half of the total variance with no relationship between phylogeny and elemental stoichiometry. Furthermore, our data indicated that variability in C:P, N:P and C:N within Bacillariophyceae (diatoms) was as high as that among all of the isolates that we examined. In addition, a linear statistical model identified a positive relationship between diatom cell volume and C:P and N:P. Among all of the isolates that we examined, the statistical model identified temperature as a significant factor, consistent with the temperature-dependent translation efficiency model, but temperature only explained 5\% of the total statistical model variance. While some of our results support data from previous field studies, the high variability of elemental ratios within Bacillariophyceae contradicts previous work that suggests that this cosmopolitan group of microalgae has consistently low C:P and N:P ratios in comparison with other groups.}, keywords = {cell size, Diatom, Dinoflagellate, eukaryote, frontiers in microbiology, frontiersin, Growth, org, protist, prymnesiophyte, RCC103, RCC1242, RCC1562, RCC4023, RCC449, RCC931, temperature, www}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.00543}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2018.00543/full}, author = {Garcia, Nathan S. and Sexton, Julie and Riggins, Tracey and Brown, Jeff and Lomas, Michael W. and Martiny, Adam C.} } @article {Carrillo2018, title = {Identification and analysis of OsttaDSP, a phosphoglucan phosphatase from Ostreococcus tauri}, journal = {PLOS ONE}, volume = {13}, number = {1}, year = {2018}, note = {tex.mendeley-tags: RCC745}, month = {jan}, pages = {e0191621}, keywords = {RCC745}, issn = {1932-6203}, doi = {10.1371/journal.pone.0191621}, url = {http://dx.plos.org/10.1371/journal.pone.0191621}, author = {Carrillo, Julieta B and Gomez-Casati, Diego F. and Mart{\'\i}n, Mariana and Busi, Maria V.}, editor = {Permyakov, Eugene A.} } @article {Moniruzzaman2018, title = {Infection by a giant virus (AaV) induces widespread physiological reprogramming in aureococcus anophagefferens CCMP1984 {\textendash} a harmful bloom algae}, journal = {Frontiers in Microbiology}, volume = {9}, number = {April}, year = {2018}, note = {tex.mendeley-tags: RCC4094}, month = {apr}, pages = {1{\textendash}16}, abstract = {While viruses with distinct phylogenetic origins and different nucleic acid types can infect and lyse eukaryotic phytoplankton, " giant " dsDNA viruses have been found to be associated with important ecological processes, including the collapse of algal blooms. However, the molecular aspects of giant virus {\textendash} host interactions remain largely unknown. AaV, a giant virus in the Mimiviridae clade, is known to play a critical role in regulating the fate of brown tide blooms caused by the pelagophyte Aureococcus anophagefferens. To understand the physiological response of A. anophagefferens CCMP1984 upon AaV infection, we studied the transcriptomic landscape of this host-virus pair over an entire infection cycle using a RNA-sequencing approach. A massive transcriptional reprogramming of the host was evident as early as 5 min post-infection, with modulation of specific processes likely related to both host defense mechanism(s) and viral takeover of the cell. Infected Aureococcus showed a relative suppression of host-cell transcripts associated with photosynthesis, cytoskeleton formation, fatty acid and carbohydrate biosynthesis. In contrast, host cell processes related to protein synthesis, polyamine biosynthesis, cellular respiration, transcription and RNA processing were overrepresented compared to the healthy cultures at different stages of the infection cycle. A large number of redox active host-selenoproteins were overexpressed, which suggested that viral replication and assembly progresses in a highly oxidative environment. The majority (99.2\%) of annotated AaV genes were expressed at some point during the infection cycle and demonstrated a clear temporal-expression pattern and an increasing relative expression for the majority of the genes through the time course. We detected a putative early promoter motif for AaV, which was highly similar to the early promoter elements of two other Mimiviridae members, indicating some degree of evolutionary conservation of gene regulation within this clade. This large-scale transcriptome study provides the insight into the Aureococcus {\textquoteright}virocell{\textquoteright}, and establishes a foundation to test hypotheses regarding metabolic and regulatory processes critical for AaV and other Mimiviridae members.}, keywords = {Algal viruses, brown, Host-virus interaction, Mimiviridae, RCC4094, transcriptional profiles}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.00752}, url = {http://dx.doi.org/10.1101/256149 http://journal.frontiersin.org/article/10.3389/fmicb.2018.00752/full}, author = {Moniruzzaman, Mohammad and Gann, Eric R and Wilhelm, Steven W} } @article {Trainic, title = {Infection dynamics of a bloom-forming alga and its virus determine airborne coccolith emission from seawater}, journal = {iScience}, year = {2018}, note = {tex.mendeley-tags: RCC1216}, month = {aug}, abstract = {Summary Sea spray aerosols (SSA), have a profound effect on the climate; however, the contribution of oceanic microbial activity to SSA is not fully established. We assessed aerosolization of the calcite units (coccoliths) that compose the exoskeleton of the cosmopolitan bloom-forming coccolithophore, Emiliania huxleyi. Airborne coccolith emission occurs in steady-state conditions and increases by an order of magnitude during E. huxleyi infection by E. huxleyi virus (EhV). Airborne to seawater coccolith ratio is 1:108, providing estimation of airborne concentrations from seawater concentrations. The coccoliths{\textquoteright} unique aerodynamic structure yields a characteristic settling velocity of \~0.01 cm s-1, \~25 times slower than average sea salt particles, resulting in coccolith fraction enrichment in the air. The calculated enrichment was established experimentally, indicating that coccoliths may be key contributors to coarse mode SSA surface area, comparable with sea salt aerosols. This study suggests a coupling between key oceanic microbial interactions and fundamental atmospheric processes like SSA formation.}, keywords = {Atmospheric Science, Biogeoscience, Earth Sciences, Marine Organism, RCC1216}, issn = {25890042}, doi = {10.1016/j.isci.2018.07.017}, url = {https://www.cell.com/iscience/fulltext/S2589-0042(18)30105-6 https://linkinghub.elsevier.com/retrieve/pii/S2589004218301056}, author = {Trainic, Miri and Koren, Ilan and Sharoni, Shlomit and Frada, Miguel and Segev, Lior and Rudich, Yinon and Vardi, Assaf} } @article {Piedade2018, title = {Influence of irradiance and temperature on the virus MpoV - 45T infecting the arctic picophytoplankter micromonas polaris}, journal = {Viruses}, year = {2018}, note = {tex.mendeley-tags: RCC2257,RCC2258}, pages = {1{\textendash}17}, abstract = {Arctic marine ecosystems are currently undergoing rapid changes in temperature and light availability. Picophytoplankton, such as Micromonas polaris, are predicted to benefit from such changes. However, little is known about how these environmental changes affect the viruses that exert a strong mortality pressure on these small but omnipresent algae. Here we report on one-step infection experiments, combined with measurements of host physiology and viability, with 2 strains of M. polaris and the virus MpoV-45T under 3 light intensities (5, 60 and 160 ??mol quanta m-2 s-1), 2 light period regimes (16:8 and 24:0 h light:dark cycle) and 2 temperatures (3 and 7 {\textdegree}C). Our results show that low light intensity (16:8 h light:dark) delayed the decline in photosynthetic efficiency and cell lysis, while decreasing burst size by 46\%. In contrast, continuous light (24:0 h light:dark) shortened the latent period by 5 h for all light intensities, and even increased the maximum virus production rate and burst size under low light (by 157 and 69\%, respectively). Higher temperature (7 {\textdegree}C vs 3 {\textdegree}C) led to earlier cell lysis and increased burst size (by 19\%), except for the low light conditions. These findings demonstrate the ecological importance of light in combination with temperature as a controlling factor for Arctic phytoplankton host and virus dynamics seasonally, even more so in the light of global warming.}, keywords = {arctic algal viruses, global climate change, light intensity, light regime, RCC2257, RCC2258, virus growth}, issn = {1999-4915}, doi = {10.3390/v10120676}, author = {Piedade, Gon{\c c}alo J and Wesdorp, Ella M and Borbolla, Elena Montenegro and Maat, Douwe S} } @article {Smallwood2018, title = {Integrated systems biology and imaging of the smallest free-living eukaryote Ostreococcus tauri}, journal = {bioRxiv}, year = {2018}, note = {tex.mendeley-tags: RCC745}, keywords = {? No DOI found, RCC745}, author = {Smallwood, Authors Chuck R and Chen, Jian-hua and Kumar, Neeraj and Chrisler, William and Samuel, O and Kyle, Jennifer E and Nicora, Carrie D and Boudreau, Rosanne and Ekman, Axel and Kim, K and Moore, Ronald J and Mcdermott, Gerry and Cannon, William R and Evans, James E} } @article {Rastogi2017, title = {Integrative analysis of large scale transcriptome data draws a comprehensive landscape of Phaeodactylum tricornutum genome and evolutionary origin of diatoms}, journal = {Scientific Reports}, volume = {8}, number = {1}, year = {2018}, note = {ISBN: 4159801823106 Publisher: Springer US tex.mendeley-tags: RCC2967}, month = {dec}, pages = {4834}, abstract = {2 3 Diatoms are one of the most successful and ecologically important groups of eukaryotic 4 phytoplankton in the modern ocean. Deciphering their genomes is a key step towards better 5 understanding of their biological innovations, evolutionary origins, and ecological 6 underpinnings. Here, we have used 90 RNA-Seq datasets from different growth conditions 7 combined with published expressed sequence tags and protein sequences from multiple taxa 8 to explore the genome of the model diatom Phaeodactylum tricornutum, and introduce 1,489 9 novel genes. The new annotation additionally permitted the discovery for the first time of 10 extensive alternative splicing (AS) in diatoms, including intron retention and exon skipping 11 which increases the diversity of transcripts to regulate gene expression in response to nutrient 12 limitations. In addition, we have used up-to-date reference sequence libraries to dissect the 13 taxonomic origins of diatom genomes. We show that the P. tricornutum genome is replete in 14 lineage-specific genes, with up to 47\% of the gene models present only possessing 15 orthologues in other stramenopile groups. Finally, we have performed a comprehensive de 16 novo annotation of repetitive elements showing novel classes of TEs such as SINE, MITE, LINE 17 and TRIM/LARD. This work provides a solid foundation for future studies of diatom gene 18 function, evolution and ecology.}, keywords = {RCC2967}, issn = {2045-2322}, doi = {10.1038/s41598-018-23106-x}, url = {https://www.biorxiv.org/content/early/2017/08/14/176024\%0Ahttp://dx.doi.org/10.1101/176024 http://www.nature.com/articles/s41598-018-23106-x}, author = {Rastogi, Achal and Maheswari, Uma and Dorrell, Richard G. and Vieira, Fabio Rocha Jimenez and Maumus, Florian and Kustka, Adam and McCarthy, James and Allen, Andy E. and Kersey, Paul and Bowler, Chris and Tirichine, Leila} } @article {Grebert2018, title = {Light color acclimation is a key process in the global ocean distribution of Synechococcus cyanobacteria}, journal = {Proceedings of the National Academy of Sciences}, volume = {in press}, year = {2018}, note = {tex.mendeley-tags: 2018,RCC1016,RCC1017,RCC1018,RCC1020,RCC1023,RCC1027,RCC1030,RCC1031,RCC1084,RCC1085,RCC1086,RCC1087,RCC1096,RCC1097,RCC1649,RCC1661,RCC1688,RCC2032,RCC2033,RCC2035,RCC2319,RCC2366,RCC2368,RCC2369,RCC2370,RCC2372,RCC2373,RCC2374,RCC2375,RCC2376,RCC2378,RCC2379,RCC2380,RCC2381,RCC2382,RCC2383,RCC2384,RCC2385,RCC2415,RCC2432,RCC2433,RCC2434,RCC2435,RCC2436,RCC2437,RCC2438,RCC2457,RCC2525,RCC2526,RCC2527,RCC2528,RCC2529,RCC2530,RCC2532,RCC2533,RCC2534,RCC2536,RCC2553,RCC2554,RCC2555,RCC2556,RCC2567,RCC2568,RCC2569,RCC2570,RCC2571,RCC2673,RCC30,RCC3010,RCC3012,RCC3014,RCC307,RCC316,RCC318,RCC325,RCC326,RCC328,RCC37,RCC44,RCC46,RCC47,RCC515,RCC539,RCC542,RCC543,RCC550,RCC552,RCC553,RCC555,RCC556,RCC557,RCC558,RCC559,RCC62,RCC650,RCC66,RCC752,RCC753,RCC790,RCC791,RCC792,RCC793,RCC794,sbr?hyto?app}, month = {feb}, pages = {201717069}, abstract = {Marine Synechococcus cyanobacteria are major contributors to global oceanic primary production and exhibit a unique diversity of photosynthetic pigments, allowing them to exploit a wide range of light niches. However, the relationship between pigment content and niche partitioning has remained largely undetermined so far due to the lack of a single-genetic marker resolving all pigment types (PT). Here, we developed a novel and robust method based on three distinct marker genes to estimate the relative abundance of all Synechococcus PTs from metagenomes. Analysis of the Tara Oceans dataset allowed us to unveil for the first time the global distribution of Synechococcus PTs and to decipher their realized environmental niches. Green-light specialists (PT 3a) dominated in warm, green equatorial waters, whereas blue-light specialists (PT 3c) were particularly abundant in oligotrophic areas. Type IV chromatic acclimaters (CA4-A/B), which are able to dynamically modify their light absorption properties to maximally absorb green or blue light, were unexpectedly the most abundant PT in our dataset and predominated at depth and high latitudes. We also identified local populations in which CA4 might be inactive due to the lack of specific CA4 genes, notably in warm high nutrient low chlorophyll areas. Major ecotypes within clades I-IV and CRD1 were preferentially associated with a particular PT, while others exhibited a wide range of PTs. Altogether, this study brings unprecedented insights into the ecology of Synechococcus PTs and highlights the complex interactions between vertical phylogeny, pigmentation and environmental parameters that shape Synechococcus populations and evolution.}, keywords = {2018, RCC1016, RCC1017, RCC1018, RCC1020, RCC1023, RCC1027, RCC1030, RCC1031, rcc1084, RCC1085, RCC1086, RCC1087, RCC1096, RCC1097, RCC1649, RCC1661, RCC1688, RCC2032, RCC2033, RCC2035, RCC2319, RCC2366, RCC2368, RCC2369, RCC2370, RCC2372, RCC2373, RCC2374, RCC2375, RCC2376, RCC2378, RCC2379, rcc2380, RCC2381, rcc2382, RCC2383, RCC2384, RCC2385, RCC2415, RCC2432, RCC2433, RCC2434, RCC2435, RCC2436, RCC2437, RCC2438, RCC2457, RCC2525, RCC2526, RCC2527, RCC2528, RCC2529, RCC2530, RCC2532, RCC2533, RCC2534, RCC2536, RCC2553, RCC2554, RCC2555, RCC2556, RCC2567, RCC2568, RCC2569, RCC2570, RCC2571, RCC2673, rcc30, RCC3010, RCC3012, RCC3014, RCC307, RCC316, RCC318, RCC325, RCC326, RCC328, RCC37, RCC44, RCC46, RCC47, RCC515, rcc539, RCC542, RCC543, RCC550, RCC552, RCC553, rcc555, RCC556, RCC557, RCC558, RCC559, RCC62, RCC650, RCC66, rcc752, RCC753, RCC790, rcc791, RCC792, RCC793, RCC794, sbr?hyto?app}, issn = {0027-8424}, doi = {10.1073/pnas.1717069115}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1717069115}, author = {Gr{\'e}bert, Th{\'e}ophile and Dor{\'e}, Hugo and Partensky, Fr{\'e}d{\'e}ric and Farrant, Gregory K. and Boss, Emmanuel S. and Picheral, Marc and Guidi, Lionel and Pesant, St{\'e}phane and Scanlan, David J. and Wincker, Patrick and Acinas, Silvia G. and Kehoe, David M. and Garczarek, Laurence} } @article {Delmont2018, title = {Linking pangenomes and metagenomes: the Prochlorococcus metapangenome}, journal = {PeerJ}, volume = {6}, year = {2018}, note = {ISBN: 2167-8359 tex.mendeley-tags: RCC156,RCC158,RCC162,RCC269,RCC278,RCC296,RCC3377,RCC407}, pages = {e4320}, abstract = {Pangenomes offer detailed characterizations of core and accessory genes found in a set of closely related microbial genomes, generally by clustering genes based on sequence homology. In comparison, metagenomes facilitate highly resolved investigations of the relative distribution of microbial genomes and individual genes across environments through read recruitment analyses. Combining these complementary approaches can yield unique insights into the functional basis of microbial niche partitioning and fitness, however, advanced software solutions are lacking. Here we present an integrated analysis and visualization strategy that provides an interactive and reproducible framework to generate pangenomes and to study them in conjunction with metagenomes. To investigate its utility, we applied this strategy to a Prochlorococcus pangenome in the context of a large-scale marine metagenomic survey. The resulting Prochlorococcus metapangenome revealed remarkable differential abundance patterns between very closely related isolates that belonged to the same phylogenetic cluster and that differed by only a small number of gene clusters in the pangenome. While the relationships between these genomes based on gene clusters correlated with their environmental distribution patterns, phylogenetic analyses using marker genes or concatenated single-copy core genes did not recapitulate these patterns. The metapangenome also revealed a small set of core genes that mostly occurred in hypervariable genomic islands of the Prochlorococcus populations, which systematically lacked read recruitment from surface ocean metagenomes. Notably, these core gene clusters were all linked to sugar metabolism, suggesting potential benefits to Prochlorococcus from a high sequence diversity of sugar metabolism genes. The rapidly growing number of microbial genomes and increasing availability of environmental metagenomes provide new opportunities to investigate the functioning and the ecology of microbial populations, and metapangenomes can provide unique insights for any taxon and biome for which genomic and sufficiently deep metagenomic data are available.}, keywords = {RCC156, RCC158, rcc162, RCC269, RCC278, rcc296, RCC3377, RCC407}, issn = {2167-8359}, doi = {10.7717/peerj.4320}, url = {https://peerj.com/articles/4320}, author = {Delmont, Tom O. and Eren, A. Murat} } @article {Liefer2018, title = {Nitrogen starvation induces distinct photosynthetic responses and recovery dynamics in diatoms and prasinophytes}, journal = {PLOS ONE}, volume = {13}, number = {4}, year = {2018}, note = {ISBN: 1111111111 tex.mendeley-tags: RCC745}, month = {apr}, pages = {e0195705}, abstract = {Nitrogen stress is an important control on the growth of phytoplankton and varying responses to this common condition among taxa may affect their relative success within phytoplankton communities.We analyzed photosynthetic responses to nitrogen (N) stress in two classes of phytoplankton that often dominate their respective size ranges, diatoms and prasinophytes, selecting species of distinct niches within each class. Changes in photosynthetic structures appeared similar within each class during N stress, but photophysiological and growth responses were more species -or niche-specific. In the coastal diatom Thalassiosira pseudonana and the oceanic diatom T. weissflogii, N starvation induced large declines in photosynthetic pigments and Photosystem II (PSII) quantity and activity as well as increases in the effective absorption cross-section of PSII photochemistry (σ{\textquoteright}PSII). These diatoms also increased photoprotection through energy-dependent non-photochemical quenching (NPQ) during N starvation. Resupply of N in diatoms caused rapid recovery of growth and relaxation of NPQ, while recovery of PSII photochemistry was slower. In contrast, the prasinophytes Micromonas sp., an Arctic Ocean species, and Ostreococcus tauri, a temperate coastal eutrophile, showed little change in photosynthetic pigments and structures and a decline or no change, respectively, inσ{\textquoteright}PSII with N starvation. Growth and PSII function recovered quickly in Micromonas sp. after resupply of N while O. tauri failed to recover N-replete levels of electron transfer from PSII and growth, possibly due to their distinct photoprotective strategies. O. tauri induced energy-dependent NPQ for photoprotection that may suit its variable and nutrient-rich habitat. Micromonas sp. relies upon both energy-dependent NPQ and a sustained, energy-independent NPQ mechanism. A strategy in Micromonas sp. that permits photoprotection with little change in photosynthetic structures is consistent with its Arctic niche, where low temperatures and thus low biosynthetic rates create higher opportunity costs to rebuild photosynthetic structures.}, keywords = {RCC745}, issn = {1932-6203}, doi = {10.1371/journal.pone.0195705}, url = {http://dx.plos.org/10.1371/journal.pone.0195705}, author = {Liefer, Justin D and Garg, Aneri and Campbell, Douglas A and Irwin, Andrew J and Finkel, Zoe V}, editor = {Ianora, Adrianna} } @article {Partensky2018, title = {A novel species of the marine cyanobacterium Acaryochloris with a unique pigment content and lifestyle}, journal = {Scientific Reports}, volume = {8}, number = {1}, year = {2018}, note = {tex.mendeley-tags: RCC1774}, month = {dec}, pages = {9142}, keywords = {RCC1774}, issn = {2045-2322}, doi = {10.1038/s41598-018-27542-7}, url = {http://www.nature.com/articles/s41598-018-27542-7}, author = {Partensky, Fr{\'e}d{\'e}ric and Six, Christophe and Ratin, Morgane and Garczarek, Laurence and Vaulot, Daniel and Probert, Ian and Calteau, Alexandra and Gourvil, Priscillia and Marie, Dominique and Gr{\'e}bert, Th{\'e}ophile and Bouchier, Christiane and Le Panse, Sophie and Gachenot, Martin and Rodr{\'\i}guez, Francisco and Garrido, Jos{\'e} L.} } @article {Yamada2018, title = {Ontogenetic analysis of siliceous cell wall formation in Triparma laevis f. inornata (Parmales, Stramenopiles)}, journal = {Journal of Phycology}, year = {2018}, note = {ISBN: 0000000266291 tex.mendeley-tags: RCC4665}, month = {oct}, pages = {0{\textendash}2}, keywords = {RCC4665}, issn = {00223646}, doi = {10.1111/jpy.12800}, url = {http://doi.wiley.com/10.1111/jpy.12800}, author = {Yamada, Kazumasa and Katsura, Hirotaka and No{\"e}l, Mary-H{\'e}l{\`e}ne and Ichinomiya, Mutsuo and Kuwata, Akira and Sato, Shinya and Yoshikawa, Shinya} } @article {Henriquez-Castillo2018, title = {Ostreococcus tauri luminescent reporter lines as biosensors for detecting pollution from copper-mine tailing effluents in coastal environments}, journal = {Frontiers in Environmental Science}, volume = {6}, number = {May}, year = {2018}, note = {tex.mendeley-tags: RCC745}, month = {may}, pages = {1{\textendash}11}, keywords = {biosensors, CDKA, copper pollution, ferritin, frontiers in environmental science, frontiersin, luciferase reporter, mine tailings, org, Ostreococcus, RCC745, www}, issn = {2296-665X}, doi = {10.3389/fenvs.2018.00022}, url = {https://www.frontiersin.org/article/10.3389/fenvs.2018.00022/full}, author = {Henr{\'\i}quez-Castillo, Carlos and Botebol, Hugo and Mouton, Adelaide and Ram{\'\i}rez-Flandes, Salvador and Lozano, Jean-Claude and Lelandais, Gaelle and Andrade, Santiago and Trefault, Nicole and de la Iglesia, Rodrigo and Bouget, Fran{\c c}ois-Yves} } @article {Moldovan2018, title = {Pangenomic definition of prokaryotic species and the phylogenetic structure of prochlorococcus spp.}, journal = {Frontiers in Microbiology}, volume = {9}, number = {March}, year = {2018}, note = {tex.mendeley-tags: RCC158,RCC162,RCC269,RCC278,RCC3307,RCC407}, pages = {1{\textendash}11}, keywords = {monophyly, pangenome, paraphyly, prokaryotic species, RCC158, rcc162, RCC269, RCC278, RCC3307, RCC407, species definition, taxonomy}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.00428}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2018.00428/full}, author = {Moldovan, Mikhail A. and Gelfand, Mikhail S.} } @article {Mizrachi2018, title = {Phenotypic variability in chloroplast redox state predicts cell fate in a marine diatom}, journal = {bioRxiv}, year = {2018}, note = {arXiv: 319517 tex.arxivid: 319517 tex.mendeley-tags: RCC2967}, keywords = {RCC2967}, doi = {10.1101/319517}, author = {Mizrachi, Avia and Graff, Shiri and Creveld, Van and Shapiro, Orr H and Rosenwasser, Shilo} } @article {Fiore2018, title = {A phosphate starvation response gene (psr1-like) is present and expressed in Micromonas pusilla and other marine algae}, journal = {bioRxiv}, year = {2018}, note = {tex.mendeley-tags: RCC299,RCC834}, keywords = {? No DOI found, RCC299, RCC834}, url = {http://dx.doi.org/10.1101/484824}, author = {Fiore, Cara L. and Alexander, Harriet and Soule, Melissa C. Kido and Kujawinski, Elizabeth B.} } @article {Klinger2018, title = {Plastid transcript editing across dinoflagellate lineages shows lineage-specific application but conserved trends}, journal = {Genome Biology and Evolution}, volume = {10}, number = {April}, year = {2018}, note = {tex.mendeley-tags: RCC1513}, pages = {1019{\textendash}1038}, abstract = {Dinoflagellates are a group of unicellular protists with immense ecological and evolutionary significance and cell biological diversity. Of the photosynthetic dinoflagellates, the majority possess a plastid containing the pigment peridinin, whereas some lineages have replaced this plastid by serial endosymbiosis with plastids of distinct evolutionary affiliations, including a fucoxanthin pigment-containing plastid of haptophyte origin. Previous studies have described the presence of widespread substitutional RNA editing in peridinin and fucoxanthin plastid genes. Because reports of this process have been limited to manual assessment of individual lineages, global trends concerning this RNA editing and its effect on the biological function of the plastid are largely unknown. Using novel bioinformatic methods, we examine the dynamics and evolution of RNA editing over a large multispecies data set of dinoflagellates, including novel sequence data from the peridinin dinoflagellate Pyrocystis lunula and the fucoxanthin dinoflagellate Karenia mikimotoi. We demonstrate that while most individual RNA editing events in dinoflagellate plastids are restricted to single species, global patterns, and functional consequences of editing are broadly conserved. We find that editing is biased toward specific codon positions and regions of genes, and generally corrects otherwise deleterious changes in the genome prior to translation, though this effect is more prevalent in peridinin than fucoxanthin lineages. Our results support a model for promiscuous editing application subsequently shaped by purifying selection, and suggest the presence of an underlying editing mechanism transferred from the peridinin-containing ancestor into fucoxanthin plastids postendosymbiosis, with remarkably conserved functional consequences in the new lineage.}, keywords = {constructive neutral evolution, Dinoflagellate, plastid, RCC1513, serial endosymbiosis, transcript editing}, issn = {1759-6653}, doi = {10.1093/gbe/evy057}, url = {https://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evy057/4935245}, author = {Klinger, Christen M and Paoli, Lucas and Newby, Robert J and Wang, Matthew Yu-Wei and Carroll, Hyrum D and Leblond, Jeffrey D and Howe, Christopher J and Dacks, Joel B and Bowler, Chris and Cahoon, A Bruce and Dorrell, Richard G and Richardson, Elisabeth} } @article {yau_rapidity_2018, title = {Rapidity of Genomic Adaptations to Prasinovirus Infection in a Marine Microalga}, journal = {Viruses}, volume = {10}, number = {8}, year = {2018}, note = {Number: 8 Publisher: Multidisciplinary Digital Publishing Institute}, pages = {441}, abstract = {Prasinoviruses are large dsDNA viruses commonly found in aquatic systems worldwide, where they can infect and lyse unicellular prasinophyte algae such as Ostreococcus. Host susceptibility is virus strain-specific, but resistance of susceptible Ostreococcus tauri strains to a virulent virus arises frequently. In clonal resistant lines that re-grow, viruses are usually present for many generations, and genes clustered on chromosome 19 show physical rearrangements and differential expression. Here, we investigated changes occurring during the first two weeks after inoculation of the prasinovirus OtV5. By serial dilutions of cultures at the time of inoculation, we estimated the frequency of resistant cells arising in virus-challenged O. tauri cultures to be 10\−3\–10\−4 of the inoculated population. Re-growing resistant cells were detectable by flow cytometry 3 days post-inoculation (dpi), visible re-greening of cultures occurred by 6 dpi, and karyotypic changes were visually detectable at 8 dpi. Resistant cell lines showed a modified spectrum of host-virus specificities and much lower levels of OtV5 adsorption.}, keywords = {adsorption, Chromosome, host range, karyotype, mamiellophyceae, phycodnaviridae, RCC1105, RCC4221, RCC4223, rearrangement, resistance, specificity, \textitOstreococcus tauri}, doi = {10.3390/v10080441}, url = {https://www.mdpi.com/1999-4915/10/8/441}, author = {Yau, Sheree and Caravello, Ga{\"e}tan and Fonvieille, Nad{\`e}ge and Desgranges, Elodie and Moreau, Herv{\'e} and Grimsley, Nigel} } @article {EMI4:EMI412614, title = {Relative stability of ploidy in a marine Synechococcus across various growth conditions}, journal = {Environmental Microbiology Reports}, year = {2018}, note = {tex.mendeley-tags: RCC752}, month = {feb}, pages = {in press}, abstract = {Marine picocyanobacteria of the genus Synechococcus are ubiquitous phototrophs in oceanic systems. Consistent with these organisms occupying vast tracts of the nutrient impoverished ocean, most marine Synechococcus so far studied are monoploid i.e. contain a single chromosome copy. The exception is the oligoploid strain Synechococcus sp. WH7803, which on average possesses around 4 chromosome copies. Here, we set out to understand the role of resource availability (through nutrient deplete growth) and physical stressors (UV, exposure to low and high temperature) in regulating ploidy level in this strain. Using qPCR to assay ploidy status we demonstrate the relative stability of chromosome copy number in Synechococcus sp. WH7803. Such robustness in maintaining an oligoploid status even under nutrient and physical stress is indicative of a fundamental role, perhaps facilitating recombination of damaged DNA regions as a result of prolonged exposure to oxidative stress, or allowing added flexibility in gene expression via possessing multiple alleles. This article is protected by copyright. All rights reserved.}, keywords = {rcc752}, issn = {17582229}, doi = {10.1111/1758-2229.12614}, url = {http://dx.doi.org/10.1111/1758-2229.12614 http://doi.wiley.com/10.1111/1758-2229.12614}, author = {Perez-Sepulveda, Blanca and Pitt, Frances and N{\textquoteright}Guyen, An Ngoc and Ratin, Morgane and Garczarek, Laurence and Millard, Andrew and Scanlan, David J} } @article {Walker2018, title = {The requirement for calcification differs between ecologically important coccolithophore species}, journal = {New Phytologist}, volume = {in press}, year = {2018}, note = {tex.mendeley-tags: RCC1731}, month = {jun}, keywords = {Calcification, coccolithophore, Coccolithus braarudii, Emiliania huxleyi, phytoplankton, rcc1731}, issn = {0028646X}, doi = {10.1111/nph.15272}, url = {http://doi.wiley.com/10.1111/nph.15272}, author = {Walker, Charlotte E. and Taylor, Alison R. and Langer, Gerald and Durak, Gra{\.z}yna M. and Heath, Sarah and Probert, Ian and Tyrrell, Toby and Brownlee, Colin and Wheeler, Glen L.} } @article {Muller2018, title = {Stable isotope fractionation of strontium in coccolithophore calcite: Influence of temperature and carbonate chemistry}, journal = {Geobiology}, volume = {16}, number = {3}, year = {2018}, note = {Publisher: John Wiley \& Sons, Ltd (10.1111) tex.mendeley-tags: RCC1200}, month = {may}, pages = {297{\textendash}306}, abstract = {Abstract Marine calcifying eukaryotic phytoplankton (coccolithophores) is a major contributor to the pelagic production of CaCO3 and plays an important role in the biogeochemical cycles of C, Ca and other divalent cations present in the crystal structure of calcite. The geochemical signature of coccolithophore calcite is used as palaeoproxy to reconstruct past environmental conditions and to understand the underlying physiological mechanisms (vital effects) and precipitation kinetics. Here, we present the stable Sr isotope fractionation between seawater and calcite (?88/86Sr) of laboratory cultured coccolithophores in individual dependence of temperature and seawater carbonate chemistry. Coccolithophores were cultured within a temperature and a pCO2 range from 10 to 25{\textdegree}C and from 175 to 1,240 ?atm, respectively. Both environmental drivers induced a significant linear increase in coccolith stable Sr isotope fractionation. The temperature correlation at constant pCO2 for Emiliania huxleyi and Coccolithus braarudii is expressed as ?88/86Sr = ?7.611 ? 10?3 T + 0.0061. The relation of ?88/86Sr to pCO2 was tested in Emiliania huxleyi at 10 and 20{\textdegree}C and resulted in ?88/86Sr = ?5.394 ? 10?5 pCO2 ? 0.0920 and ?88/86Sr = ?5.742 ? 10?5 pCO2 ? 0.1351, respectively. No consistent relationship was found between coccolith ?88/86Sr and cellular physiology impeding a direct application of fossil coccolith ?88/86Sr as coccolithophore productivity proxy. An overall significant correlation was detected between the elemental distribution coefficient (DSr) and ?88/86Sr similar to inorganic calcite with a physiologically induced offset. Our observations indicate (i) that temperature and pCO2 induce specific effects on coccolith ?88/86Sr values and (ii) that strontium elemental ratios and stable isotope fractionation are mainly controlled by precipitation kinetics when embedded into the crystal lattice and subject to vital effects during the transmembrane transport from seawater to the site of calcification. These results provide an important step to develop a coccolith ?88/86Sr palaeoproxy complementing the existing toolbox of palaeoceanography.}, keywords = {coccolithophores, paleoproxy calibration, phytoplankton, RCC1200, stable Sr isotope fractionation}, issn = {1472-4677}, doi = {10.1111/gbi.12276}, url = {https://doi.org/10.1111/gbi.12276}, author = {M{\"u}ller, M N and Krabbenh{\"o}ft, A and Vollstaedt, H and Brandini, F P and Eisenhauer, A} } @article {Rosas-Navarro2018, title = {Temperature effects on sinking velocity of different Emiliania huxleyi strains}, journal = {PLOS ONE}, volume = {13}, number = {3}, year = {2018}, note = {ISBN: 1111111111 tex.mendeley-tags: IAN01,RCC1252,RCC1710}, pages = {e0194386}, abstract = {The sinking properties of three strains of Emiliania huxleyi in response to temperature changes were examined. We used a recently proposed approach to calculate sinking velocities from coccosphere architecture, which has the advantage to be applicable not only to culture samples, but also to field samples including fossil material. Our data show that temperature in the sub-optimal range impacts sinking velocity of E. huxleyi. This response is widespread among strains isolated in different locations and moreover comparatively predictable, as indicated by the similar slopes of the linear regressions. Sinking velocity was positively correlated to temperature as well as individual cell PIC/POC over the sub-optimum to optimum temperature range in all strains. In the context of climate change our data point to an important influence of global warming on sinking velocities. It has recently been shown that seawater acidification has no effect on sinking velocity of a Mediterranean E. huxleyi strain, while nutrient limitation seems to have a small negative effect on sinking velocity. Given that warming, acidification, and lowered nutrient availability will occur simultaneously under climate change scenarios, the question is what the net effect of different influential factors will be. For example, will the effects of warming and nutrient limitation cancel? This question cannot be answered conclusively but analyses of field samples in addition to laboratory culture studies will improve predictions because in field samples multi-factor influences and even evolutionary changes are not excluded. As mentioned above, the approach of determining sinking rate followed here is applicable to field samples. Future studies could use it to analyse not only seasonal and geographic patterns but also changes in sinking velocity over geological time scales.}, keywords = {IAN01, rcc1252, rcc1710}, issn = {1932-6203}, doi = {10.1371/journal.pone.0194386}, url = {http://dx.plos.org/10.1371/journal.pone.0194386}, author = {Rosas-Navarro, Anaid and Langer, Gerald and Ziveri, Patrizia}, editor = {Johnson, Colin} } @article {Mahmoud2017, title = {Adaptation to blue light in marine synechococcus requires MpeU, an enzyme with similarity to phycoerythrobilin lyase isomerases}, journal = {Frontiers in Microbiology}, volume = {8}, number = {February}, year = {2017}, note = {tex.mendeley-tags: 2017,rcc555,sbr?hyto?app}, month = {feb}, pages = {243}, abstract = {Marine Synechococcus cyanobacteria have successfully adapted to environments with different light colors, which likely contributes to this genus being the second most abundant photosynthetic microorganism worldwide. Populations of Synechococcus that grow in deep, blue ocean waters contain large amounts of the blue-light absorbing chromophore phycourobilin (PUB) in their light harvesting complexes (phycobilisomes). Here we show that all Synechococcus strains adapted to blue light possess a gene called mpeU. MpeU is structurally similar to phycobilin lyases, enzymes that ligate chromophores to phycobiliproteins. Interruption of mpeU caused a reduction in PUB content, produced impaired phycobilisomes and reduced growth rate more strongly in blue than green light. When mpeU was reintroduced in the mpeU mutant background, the mpeU-less phenotype was complemented in terms of PUB content and phycobilisome content. Fluorescence spectra of mpeU mutant cells and purified phycobilisomes revealed red-shifted phycoerythrin emission peaks, likely indicating a defect in chromophore ligation to phycoerythrin-I (PE-I) or phycoerythrin-II (PE-II). Our results suggest that MpeU is a lyase-isomerase that attaches a phycoerythrobilin to a PEI or PEII subunit and isomerizes it to PUB. MpeU is therefore an important determinant in adaptation of Synechococcus spp. to capture photons in blue light environments throughout the world{\textquoteright}s oceans.}, keywords = {2017, Blue light, light harvesting complex, Lyase isomerase, marine cyanobacteria, Marine Synechococcus, phycobilin, Phycobilisome, Phycoerythrin, Phycourobilin, rcc555, sbr?hyto?app}, issn = {1664-302X}, doi = {10.3389/fmicb.2017.00243}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2017.00243/full}, author = {Mahmoud, Rania M. and Sanfilippo, Joseph E. and Nguyen, Adam A. and Strnat, Johann A. and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence and Abo El Kassem, Nabil and Kehoe, David M. and Schluchter, Wendy M.} } @article {Pittera2016, title = {Adaptive thermostability of light-harvesting complexes in marine picocyanobacteria}, journal = {The ISME Journal}, volume = {11}, number = {1}, year = {2017}, note = {tex.mendeley-tags: 2016,rcc1594,rcc1682,rcc2380,rcc2382,rcc752,rcc791}, pages = {112{\textendash}124}, keywords = {2016, rcc1594, rcc1682, rcc2380, rcc2382, rcc752, rcc791}, issn = {1751-7362}, doi = {10.1038/ismej.2016.102}, url = {http://www.nature.com/doifinder/10.1038/ismej.2016.102}, author = {Pittera, Justine and Partensky, Fr{\'e}d{\'e}ric and Six, Christophe} } @article {Gu2017, title = {Adenoides sinensis , a new sand-dwelling dinoflagellate species from China and reexamination of A. eludens from an Atlantic strain}, journal = {Phycologia}, volume = {57}, number = {October}, year = {2017}, note = {tex.mendeley-tags: 2017,RCC1982,rcc,sbr?hyto$_\textrmd$ipo}, pages = {1{\textendash}13}, abstract = {The sand-dwelling?1dinoflagellate generaAdenoidesandPseudadenoidesare morphologically very close butdistinct in their molecular phylogeny. We established three cultures by isolating single cells from sand samples collected inintertidal zones of Qingdao (Yellow Sea), Dongshan (South China Sea) and Brittany (English Channel, North Atlantic,France). Strain morphology was examined with light and scanning electron microscopy, and both large subunitribosomal DNA (LSU rDNA) and small subunit ribosomal DNA (SSU rDNA) sequences were amplified. Molecularphylogeny, corroborated by morphological examination showing the existence of a ventral pore, confirmed theidentification of the French strain (RCC1982) asAdenoides eludens. The Chinese strains differed fromAdenoides eludensin two additional posterior intercalary plates and differed fromPseudadenoidesin one additional apical plate having theplate formula of Po, Cp, X, 50,600, 4S, 5000, 5p, 10000or alternatively Po, Cp, X, 50,600, 5S, 5000, 3p, 20000. Maximumlikelihood and Bayesian inference carried out with concatenated LSU and SSU sequences demonstrated that the Chinesestrains were closely related but different fromA. eludensand, in corroboration with morphological evidence, supportedtheir classification as a distinct species,Adenoides sinensis sp. nov. Morphological and molecular results confirmed theclose relationship between the two generaAdenoidesandPseudadenoides.}, keywords = {2017, rcc, RCC1982, sbr?hyto$_\textrmd$ipo}, doi = {10.2216/17-76.1}, author = {Gu, Haifeng and Li, Xintian and Chom{\'e}rat, Nicolas and Luo, Zhaohe and Sarno, Diana and Gourvil, Priscillia and Balzano, Sergio and Siano, Raffaele} } @article {Ni2016, title = {Arctic Micromonas uses protein pools and non-photochemical quenching to cope with temperature restrictions on Photosystem II protein turnover}, journal = {Photosynthesis Research}, volume = {131}, number = {2}, year = {2017}, note = {ISBN: 1112001603 Publisher: Springer Netherlands tex.mendeley-tags: 2016,RCC806}, month = {feb}, pages = {203{\textendash}220}, keywords = {2016, {\'a}, Photoinactivation, photoinactivation {\'a} xanthophyll cycle, Photosystem II, Prasinophyte, prasinophyte {\'a} photosystem ii, RCC806, Xanthophyll cycle}, issn = {0166-8595}, doi = {10.1007/s11120-016-0310-6}, url = {http://link.springer.com/10.1007/s11120-016-0310-6}, author = {Ni, Guangyan and Zimbalatti, Gabrielle and Murphy, Cole D. and Barnett, Audrey B. and Arsenault, Christopher M. and Li, Gang and Cockshutt, Amanda M. and Campbell, Douglas A.} } @article {Gnouma2017, title = {Changes in fatty acids profile, monosaccharide profile and protein content during batch growth of Isochrysis galbana (T.iso)}, journal = {Aquaculture Research}, volume = {48}, number = {9}, year = {2017}, note = {Publisher: John Wiley \& Sons, Ltd (10.1111) tex.mendeley-tags: RCC1349}, month = {sep}, pages = {4982{\textendash}4990}, abstract = {Abstract To investigate the nutritional value of the marine micro-alga Isochrysis galbana Tahitian Isochrysis strain (T.iso) as an alternative feed for aquaculture during culture age, its biochemical composition was studied under autotrophic and controlled culture conditions at different growth stages: exponential phase, early and late stationary phases and decay phase. Analysis showed that C14:0, C16:0, C16:1, C18:4 (n-3) and C22:6 (n-3) were the most abundant fatty acids in this alga at different growth stages. The highest values of monounsaturated fatty acids were recorded at the late stationary and the decay phases. However, the highest levels of polyunsaturated fatty acids were observed at the early stationary phase. At all growth stages, I. galbana (T.iso) contained arabinose, xylose, mannose, galactose and glucose. Glucose represented the main sugar, and its content per dry alga biomass weight increased with increasing age of the culture and reached about fourfold in the decay phase. The maximum protein content was also observed during this last phase.}, keywords = {fatty acids, growth phases, Isochrysis galbana (T.iso), monosaccharides, proteins, RCC1349}, issn = {1355-557X}, doi = {10.1111/are.13316}, url = {https://doi.org/10.1111/are.13316}, author = {Gnouma, Asma and Sadovskaya, Irina and Souissi, Anissa and Sebai, Khaled and Medhioub, Amel and Grard, Thierry and Souissi, Sami} } @article {Dorrell2017, title = {Chimeric origins of ochrophytes and haptophytes revealed through an ancient plastid proteome}, journal = {eLife}, volume = {6}, year = {2017}, month = {may}, pages = {1{\textendash}45}, abstract = {Plastids are supported by a wide range of proteins encoded within the nucleus and imported from the cytoplasm. These plastid-targeted proteins may originate from the endosymbiont, the host, or other sources entirely. Here, we identify and characterise 770 plastid-targeted proteins that are conserved across the ochrophytes, a major group of algae including diatoms, pelagophytes and kelps, that possess plastids derived from red algae. We show that the ancestral ochrophyte plastid proteome was an evolutionary chimera, with 25\% of its phylogenetically tractable nucleus-encoded proteins deriving from green algae. We additionally show that functional mixing of host and plastid proteomes, such as through dual-targeting, is an ancestral feature of plastid evolution. Finally, we detect a clear phylogenetic signal from one ochrophyte subgroup, the lineage containing pelagophytes and dictyochophytes, in plastid-targeted proteins from another major algal lineage, the haptophytes. This may represent a possible serial endosymbiosis event deep in eukaryotic evolutionary history.}, keywords = {2017, RCC1486, RCC1523, RCC1537, RCC1587, SBR$_\textrmP$hyto$_\textrmE$PPO}, issn = {2050-084X}, doi = {10.7554/eLife.23717}, url = {http://elifesciences.org/lookup/doi/10.7554/eLife.23717}, author = {Dorrell, Richard G and Gile, Gillian and McCallum, Giselle and M{\'e}heust, Rapha{\"e}l and Bapteste, Eric P and Klinger, Christen M and Brillet-Gu{\'e}guen, Loraine and Freeman, Katalina D and Richter, Daniel J and Bowler, Chris} } @article {LopesdosSantos2017, title = {Chloropicophyceae, a new class of picophytoplanktonic prasinophytes}, journal = {Scientific Reports}, volume = {7}, number = {1}, year = {2017}, note = {tex.mendeley-tags: 2017,RCC1019,RCC1021,RCC1032,RCC1043,RCC1124,RCC138,RCC15,RCC1871,RCC19,RCC227,RCC2335,RCC2337,RCC2339,RCC287,RCC297,RCC3368,RCC3373,RCC3374,RCC3375,RCC3376,RCC3402,RCC4429,RCC4430,RCC4434,RCC4572,RCC4656,RCC696,RCC700,RCC701,RCC712,RCC713,RCC717,RCC719,RCC722,RCC726,RCC856,RCC857,RCC887,RCC917,RCC996,RCC997,RCC998,RCC999,sbr?hyto$_\textrmd$ipo}, month = {dec}, pages = {14019}, keywords = {2017, RCC1019, RCC1021, RCC1032, RCC1043, RCC1124, RCC138, RCC15, RCC1871, RCC19, RCC227, RCC2335, RCC2337, RCC2339, RCC287, RCC297, RCC3368, RCC3373, RCC3374, RCC3375, RCC3376, RCC3402, RCC4429, RCC4430, RCC4434, RCC4572, RCC4656, RCC696, RCC700, RCC701, RCC712, RCC713, RCC717, RCC719, RCC722, RCC726, RCC856, RCC857, RCC887, RCC917, RCC996, RCC997, RCC998, RCC999, sbr?hyto$_\textrmd$ipo}, issn = {2045-2322}, doi = {10.1038/s41598-017-12412-5}, url = {http://www.nature.com/articles/s41598-017-12412-5}, author = {Lopes dos Santos, Adriana and Pollina, Thibaut and Gourvil, Priscillia and Corre, Erwan and Marie, Dominique and Garrido, Jos{\'e} Luis and Rodr{\'\i}guez, Francisco and No{\"e}l, Mary-H{\'e}l{\`e}ne and Vaulot, Daniel and Eikrem, Wenche} } @article {Satjarak2017, title = {Comparative DNA sequence analyses of Pyramimonas parkeae (Prasinophyceae) chloroplast genomes}, journal = {Journal of Phycology}, volume = {53}, number = {2}, year = {2017}, note = {tex.mendeley-tags: RCC1987,RCC2009,RCC2015,RCC2500,RCC2501,RCC2502,RCC619}, month = {apr}, pages = {415{\textendash}424}, keywords = {RCC1987, RCC2009, RCC2015, RCC2500, RCC2501, RCC2502, RCC619}, issn = {00223646}, doi = {10.1111/jpy.12515}, url = {http://doi.wiley.com/10.1111/jpy.12515}, author = {Satjarak, Anchittha and Graham, Linda E.}, editor = {Wood, M.} } @article {Stuart2016, title = {Copper toxicity response influences mesotrophic S ynechococcus community structure}, journal = {Environmental Microbiology}, volume = {19}, number = {2}, year = {2017}, note = {ISBN: 3907122046 tex.mendeley-tags: 2016,RCC1086,RCC2673}, month = {feb}, pages = {756{\textendash}769}, abstract = {Picocyanobacteria from the genus Synechococcus are ubiquitous in ocean waters. Their phylogenetic and genomic diversity suggests ecological niche differentiation, but the selective forces influencing this are not well defined. Marine picocyanobacteria are sensitive to Cu toxicity, so adaptations to this stress could represent a selective force within, and between, {\textquotedblleft}species{\textquotedblright} also known as clades. We compared Cu stress responses in cultures and natural populations of marine Synechococcus from two co-occurring major mesotrophic clades (I and IV). Using custom microarrays and proteomics to characterize expression responses to Cu in the lab and field, we found evidence for a general stress regulon in marine Synechococcus. However, the two clades also exhibited distinct responses to copper. The Clade I representative induced expression of genomic island genes in cultures and Southern California Bight populations, while the Clade IV representative downregulated Fe-limitation proteins. Copper incubation experiments suggest that Clade IV populations may harbor stress-tolerant subgroups, and thus fitness tradeoffs may govern Cu-tolerant strain distributions. This work demonstrates that Synechococcus has distinct adaptive strategies to deal with Cu toxicity at both the clade and subclade level, implying that metal toxicity and stress response adaptations represent an important selective force for influencing diversity within marine Synechococcus populations. This}, keywords = {2016, alkylsuccinate, methanogenic, n -alkane, paraffin, RCC1086, RCC2673, smithella, syntrophy}, issn = {14622912}, doi = {10.1111/1462-2920.13630}, url = {http://doi.wiley.com/10.1111/1462-2920.13630}, author = {Stuart, Rhona K. and Bundy, Randelle and Buck, Kristen and Ghassemain, Majid and Barbeau, Kathy and Palenik, Brian} } @article {Gutierrez-Rodriguez2017, title = {Dimethylated sulfur compounds in symbiotic protists: A potentially significant source for marine DMS(P)}, journal = {Limnology and Oceanography}, number = {February}, year = {2017}, note = {tex.mendeley-tags: 2017,rcc1383,rcc1491,rcc3468,rcc3507,sbr?hyto$_\textrmd$ipo}, month = {feb}, keywords = {2017, rcc1383, rcc1491, rcc3468, rcc3507, sbr?hyto$_\textrmd$ipo}, issn = {00243590}, doi = {10.1002/lno.10491}, url = {http://doi.wiley.com/10.1002/lno.10491}, author = {Gutierrez-Rodriguez, Andres and Pillet, Loic and Biard, Tristan and Said-Ahmad, Ward and Amrani, Alon and Sim{\'o}, Rafel and Not, Fabrice} } @article {Organelli2017, title = {On the discrimination of multiple phytoplankton groups from light absorption spectra of assemblages with mixed taxonomic composition and variable light conditions}, journal = {Applied Optics}, volume = {56}, number = {14}, year = {2017}, note = {tex.mendeley-tags: RCC151,RCC322,RCC904}, month = {may}, pages = {3952}, abstract = {According to recommendations of the international community of phytoplankton functional type algorithm devel- opers, a set of experiments on marine algal cultures was conducted to (1) investigate uncertainties and limits in phytoplankton group discrimination from hyperspectral light absorption properties of assemblages withmixed taxo- nomic composition, and (2) evaluate the extent to which modifications of the absorption spectral features due to variable light conditions affect the optical discrimination of phytoplankton. Results showed that spectral absorption signatures of multiple species can be extracted from mixed assemblages, even at low relative contributions. Errors in retrieved pigment abundances are, however, influenced by the co-occurrence of species with similar spectral features. Plasticity of absorption spectra due to changes in light conditions weakly affects interspecific differences, with errors {\textexclamdown}21\% for retrievals of pigment concentrations from mixed assemblages.}, keywords = {RCC151, RCC322, RCC904}, issn = {0003-6935}, doi = {10.1364/AO.56.003952}, url = {https://www.osapublishing.org/abstract.cfm?URI=ao-56-14-3952}, author = {Organelli, Emanuele and Nuccio, Caterina and Lazzara, Luigi and Uitz, Julia and Bricaud, Annick and Massi, Luca} } @article {Hennon2017, title = {Diverse CO2-Induced responses in physiology and gene expression among eukaryotic phytoplankton}, journal = {Frontiers in Microbiology}, volume = {8}, number = {December}, year = {2017}, note = {tex.mendeley-tags: RCC1303}, month = {dec}, pages = {1{\textendash}14}, abstract = {With rising atmospheric CO2, phytoplankton face shifts in ocean chemistry including increased dissolved CO2 and acidification that will likely influence the relative competitive fitness of different phytoplankton taxa. Here we compared the physiological and gene expression responses of six species of phytoplankton including a diatom, a raphidophyte, two haptophytes, and two dinoflagellates to ambient (\~400 ppm) and elevated (\~800 ppm) CO2. Dinoflagellates had significantly slower growth rates and higher, yet variable, chlorophyll a per cell under elevated CO2. The other phytoplankton tended to have increased growth rates and/or decreased chlorophyll a per cell. Carbon and nitrogen partitioning of cells shifted under elevated CO2 in some species, indicating potential changes in energy fluxes due to changes in carbon concentrating mechanisms (CCM) or photorespiration. Consistent with these phenotypic changes, gene set enrichment analyses revealed shifts in energy, carbon and nitrogen metabolic pathways, though with limited overlap between species in the genes and pathways involved. Similarly, gene expression responses across species revealed few conserved CO2-responsive genes within CCM and photorespiration categories, and a survey of available transcriptomes found high diversity in biophysical CCM and photorespiration expressed gene complements between and within the four phyla represented by these species. The few genes that displayed similar responses to CO2 across phyla were from understudied gene families, making them targets for further research to uncover the mechanisms of phytoplankton acclimation to elevated CO2. These results underscore that eukaryotic phytoplankton have diverse gene complements and gene expression responses to CO2 perturbations and highlight the value of cross-phyla comparisons for identifying gene families that respond to environmental change.}, keywords = {algae, biophysical CCM, C4 CCM, carbon concentrating mechanism, carbon concentrating mechanism (CCM), ccm, photorespiration, RCC1303, transcriptomics}, issn = {1664-302X}, doi = {10.3389/fmicb.2017.02547}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2017.02547/full}, author = {Hennon, Gwenn M. M. and Hern{\'a}ndez Lim{\'o}n, Mar{\'\i}a D. and Haley, Sheean T. and Juhl, Andrew R. and Dyhrman, Sonya T.} } @article {LopesdosSantos2016, title = {Diversity and oceanic distribution of prasinophytes clade VII, the dominant group of green algae in oceanic waters}, journal = {The ISME Journal}, volume = {11}, number = {2}, year = {2017}, note = {tex.mendeley-tags: 2016,RCC1019,RCC1021,RCC1032,RCC1043,RCC1124,RCC138,RCC15,RCC1871,RCC19,RCC227,RCC2335,RCC2337,RCC2339,RCC287,RCC297,RCC3368,RCC3373,RCC3374,RCC3375,RCC3376,RCC3402,RCC4429,RCC4430,RCC4434,RCC4656,RCC696,RCC700,RCC701,RCC712,RCC713,RCC717,RCC719,RCC722,RCC726,RCC856,RCC857,RCC917,RCC996,RCC997,RCC998,RCC999,sbr?hyto$_\textrmd$ipo,sbr?hyto?ppo}, month = {feb}, pages = {512{\textendash}528}, keywords = {2016, MACUMBA, MicroB3, RCC1019, RCC1021, RCC1032, RCC1043, RCC1124, RCC138, RCC15, RCC1871, RCC19, RCC227, RCC2335, RCC2337, RCC2339, RCC287, RCC297, RCC3368, RCC3373, RCC3374, RCC3375, RCC3376, RCC3402, RCC4429, RCC4430, RCC4434, RCC4656, RCC696, RCC700, RCC701, RCC712, RCC713, RCC717, RCC719, RCC722, RCC726, RCC856, RCC857, RCC917, RCC996, RCC997, RCC998, RCC999, sbr?hyto$_\textrmd$ipo, sbr?hyto?ppo}, issn = {1751-7362}, doi = {10.1038/ismej.2016.120}, url = {http://www.nature.com/doifinder/10.1038/ismej.2016.120}, author = {Lopes dos Santos, Adriana and Gourvil, Priscillia and Tragin, Margot and No{\"e}l, Mary-H{\'e}l{\`e}ne and Decelle, Johan and Romac, Sarah and Vaulot, Daniel} } @article {Walter2017, title = {Ecogenomics and taxonomy of cyanobacteria phylum}, journal = {Frontiers in Microbiology}, volume = {8}, number = {November}, year = {2017}, note = {tex.mendeley-tags: RCC307}, month = {nov}, keywords = {charting biodiversity, ecological niches, genome-based microbial taxonomy, high-throughput sequencing technology, metagenome, microbial ecology, RCC307}, issn = {1664-302X}, doi = {10.3389/fmicb.2017.02132}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2017.02132/full}, author = {Walter, Juline M. and Coutinho, Felipe H. and Dutilh, Bas E. and Swings, Jean and Thompson, Fabiano L. and Thompson, Cristiane C.} } @article {Ruiz2017, title = {Emerging interaction patterns in the emiliania huxleyi-EhV system}, journal = {Viruses}, volume = {9}, number = {3}, year = {2017}, note = {tex.mendeley-tags: RCC1211,RCC1213,RCC1215,RCC1216,RCC1218,RCC1228,RCC1231,RCC1235,RCC1239,RCC1241,RCC1242,RCC1246,RCC1249,RCC1250,RCC1253,RCC1255,RCC1256,RCC1257,RCC1259,RCC1268,RCC1269,RCC1272,RCC1276,RCC1322,RCC1744,RCC1745,RCC1857,RCC3548,RCC3856,RCC3923,RCC3956}, month = {mar}, pages = {61}, abstract = {Viruses are thought to be fundamental in driving microbial diversity in the oceanic planktonic realm. That role and associated emerging infection patterns remain particularly elusive for eukaryotic phytoplankton and their viruses. Here we used a vast number of strains from the model system Emiliania huxleyi/Emiliania huxleyi Virus to quantify parameters such as growth rate ({\textmu}), resistance (R), and viral production (Vp) capacities. Algal and viral abundances were monitored by flow cytometry during 72-h incubation experiments. The results pointed out higher viral production capacity in generalist EhV strains, and the virus-host infection network showed a strong co-evolution pattern between E. huxleyi and EhV populations. The existence of a trade-off between resistance and growth capacities was not confirme}, keywords = {algae virus, coccolithophore, coccolithovirus, cost of, haptophyta, infectivity trade-offs, killing-the-winner, marine viral ecology, phycodnaviridae, RCC1211, RCC1213, RCC1215, RCC1216, RCC1218, RCC1228, RCC1231, RCC1235, RCC1239, RCC1241, RCC1242, RCC1246, RCC1249, RCC1250, RCC1253, RCC1255, rcc1256, RCC1257, RCC1259, RCC1268, RCC1269, RCC1272, RCC1276, RCC1322, RCC1744, RCC1745, RCC1857, RCC3548, RCC3856, RCC3923, RCC3956, resistance, viral-host interactions}, issn = {1999-4915}, doi = {10.3390/v9030061}, url = {http://www.mdpi.com/1999-4915/9/3/61}, author = {Ruiz, Eliana and Oosterhof, Monique and Sandaa, Ruth-Anne and Larsen, Aud and Pagarete, Ant{\'o}nio} } @article {Moutier2017, title = {Evolution of the scattering properties of phytoplankton cells from flow cytometry measurements}, journal = {PLoS ONE}, volume = {12}, number = {7}, year = {2017}, note = {ISBN: 1111111111 tex.mendeley-tags: RCC1,RCC950}, abstract = {Combining a modern, data-analytic perspective with a focus on applications in the social sciences, the Second Edition of Applied Regression Analysis and Generalized Linear Models provides in-depth coverage of regression analysis, generalized linear models, and closely related methods. Although the text is largely accessible to readers with a modest background in statistics and mathematics, author John Fox also presents more advanced material throughout the book. Key Updates to the Second Edition:Provides greatly enhanced coverage of generalized linear models, with an emphasis on models for categorical and count data Offers new chapters on missing data in regression models and on methods of model selection Includes expanded treatment of robust regression, time-series regression, nonlinear regression, and nonparametric regression Incorporates new examples using larger data sets Includes an extensive Web site at http://www.sagepub.com/fox that presents appendixes, data sets used in the book and for data-analytic exercises, and the data-analytic exercises themselves Intended Audience: This core text will be a valuable resource for graduate students and researchers in the social sciences (particularly sociology, political science, and psychology) and other disciplines that employ linear and related models for data analysis. High Praise for the First Edition: Even though the book is written with social scientists as the target audience, the depth of material and how it is conveyed give it far broader appeal. Indeed, I recommend it as a useful learning text and resource for researchers and students in any field that applies regression or linear models (that is, most everyone), including courses for undergraduate statistics majors.... The author is to be commended for giving us this book, which I trust will find a wide and enduring readership.-JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION [T]his wonderfully comprehensive book focuses on regression analysis and linear models.... We enthusiastically recommend this book {\textemdash} having used it in class, we know that it is thorough and well liked by students. -CHANCE}, keywords = {RCC1, RCC950}, issn = {19326203}, doi = {10.1371/journal.pone.0181180}, author = {Moutier, William and Dufor{\^e}t-Gaurier, Lucile and Thyssen, M{\'e}lilotus and Loisel, Hubert and M{\'e}riaux, Xavier and Courcot, Lucie and Dessailly, David and R{\^e}ve, Anne H{\'e}l{\`e}ne and Gr{\'e}gori, Gerald and Alvain, S{\'e}verine and Barani, Aude and Brutier, Laurent and Dugenne, Mathilde} } @article {Kuhlisch2017, title = {A fast and direct liquid chromatography-mass spectrometry method to detect and quantify polyunsaturated aldehydes and polar oxylipins in diatoms}, journal = {Limnology and Oceanography: Methods}, volume = {15}, number = {1}, year = {2017}, note = {Publisher: John Wiley \& Sons, Ltd tex.mendeley-tags: RCC75,RCC776}, month = {jan}, pages = {70{\textendash}79}, abstract = {Abstract Polyunsaturated aldehydes (PUAs) are a group of microalgal metabolites that have attracted a lot of attention due to their biological activity. Determination of PUAs has become an important routine procedure in plankton and biofilm investigations, especially those that deal with chemically mediated interactions. Here we introduce a fast and direct derivatization free method that allows quantifying PUAs in the nanomolar range, sufficient to undertake the analysis from cultures and field samples. The sample preparation requires one simple filtration step and the initiation of PUA formation by cell disruption. After centrifugation the samples are ready for measurement without any further handling. Within one chromatographic run this method additionally allows us to monitor the formation of the polar oxylipins arising from the cleavage of precursor fatty acids. The robust method is based on analyte separation and detection using ultra high performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (UHPLC-APCI MS) and enables high throughput investigations by employing an analysis time of only 5 min. Our protocol thus provides an alternative and extension to existing PUA determinations based on gas chromatography-mass spectrometry (GC-MS) with shorter run times and without any chemical derivatization. It also enables researchers with widely available LC-MS analytical platforms to monitor PUAs. Additionally, non-volatile oxylipins such as ?-oxo-acids and related compounds can be elucidated and monitored.}, keywords = {RCC75, RCC776}, issn = {1541-5856}, doi = {10.1002/lom3.10143}, url = {https://doi.org/10.1002/lom3.10143}, author = {Kuhlisch, Constanze and Deicke, Michael and Ueberschaar, Nico and Wichard, Thomas and Pohnert, Georg} } @article {Degraeve-Guilbault2017, title = {Glycerolipid characterization and nutrient deprivation-associated changes in the green picoalga ostreococcus tauri}, journal = {Plant Physiology}, volume = {173}, number = {4}, year = {2017}, note = {tex.mendeley-tags: RCC3401,RCC4222,RCC745,RCC788,RCC789,RCC802,RCC809,RCC834}, pages = {2060{\textendash}2080}, abstract = {The picoalga Ostreococcus tauri is a minimal photosynthetic eukaryote that has been used as a model system. O. tauri is known to efficiently produce docosahexaenoic acid (DHA). We provide a comprehensive study of the glycerolipidome of O. tauri and validate this species as model for related picoeukaryotes. O. tauri lipids displayed unique features that combined traits from the green and the chromalveolate lineages. The betaine lipid diacylglyceryl-hydroxymethyl-trimethyl-β-alanine and phosphatidyldimethylpropanethiol, both hallmarks of chromalveolates, were identified as presumed extraplastidial lipids. DHA was confined to these lipids, while plastidial lipids of prokaryotic type were characterized by the overwhelming presence of ω-3 C18 polyunsaturated fatty acids (FAs), 18:5 being restricted to galactolipids. C16:4, an FA typical of green microalgae galactolipids, also was a major component of O. tauri extraplastidial lipids, while the 16:4-coenzyme A (CoA) species was not detected. Triacylglycerols (TAGs) displayed the complete panel of FAs, and many species exhibited combinations of FAs diagnostic for plastidial and extraplastidial lipids. Importantly, under nutrient deprivation, 16:4 and ω-3 C18 polyunsaturated FAs accumulated into de novo synthesized TAGs while DHA-TAG species remained rather stable, indicating an increased contribution of FAs of plastidial origin to TAG synthesis. Nutrient deprivation further severely down-regulated the conversion of 18:3 to 18:4, resulting in obvious inversion of the 18:3/18:4 ratio in plastidial lipids, TAGs, as well as acyl-CoAs. The fine-tuned and dynamic regulation of the 18:3/18:4 ratio suggested an important physiological role of these FAs in photosynthetic membranes. Acyl position in structural and storage lipids together with acyl-CoA analysis further help to determine mechanisms possibly involved in glycerolipid synthesis.}, keywords = {rcc3401, RCC4222, RCC745, RCC788, RCC789, RCC802, RCC809, RCC834}, issn = {0032-0889}, doi = {10.1104/pp.16.01467}, url = {http://www.plantphysiol.org/lookup/doi/10.1104/pp.16.01467}, author = {Degraeve-Guilbault, Charlotte and Br{\'e}h{\'e}lin, Claire and Haslam, Richard and Sayanova, Olga and Marie-Luce, Glawdys and Jouhet, Juliette and Corellou, Florence} } @article {Monier2017, title = {Host-derived viral transporter protein for nitrogen uptake in infected marine phytoplankton}, journal = {Proceedings of the National Academy of Sciences}, year = {2017}, note = {tex.mendeley-tags: RCC1107,RCC1621,RCC2573,RCC2593,RCC745,RCC809}, pages = {201708097}, keywords = {rcc1107, RCC1621, RCC2573, RCC2593, RCC745, RCC809}, issn = {0027-8424}, doi = {10.1073/pnas.1708097114}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1708097114}, author = {Monier, Adam and Chambouvet, Aurelie and Milner, David S. and Attah, Victoria and Terrado, Ram{\'o}n and Lovejoy, Connie and Moreau, Herv{\'e} and Santoro, Alyson E. and Derelle, Evelyne and Richards, Thomas A.} } @article {Fischer2017, title = {Identity of the limiting nutrient (N vs. P) affects the competitive success of mixotrophs}, journal = {Marine Ecology Progress Series}, volume = {563}, year = {2017}, note = {tex.mendeley-tags: RCC744}, pages = {51{\textendash}63}, abstract = {ABSTRACT: Empirical and theoretical evidence predicts that mixotrophic bacterivores dominate over specialized heterotrophic bacterivores and specialist photoautotrophs under conditions of high light and low loss rates. Here we extend this concept towards nutrient limitation and ask whether the identity of the limiting nutrient affects the competition of mixotrophs with their specialist competitors. Due to their photosynthetic machinery, mixotrophs should have higher cellular N contents than heterotrophs and, following this assumption, a higher demand for N. Conversely, heterotrophs, with their potential high growth rates compared to mixotrophs, may have a higher demand for P (?growth rate hypothesis?). Simplified, mixotrophs should be more prone to N-limitation, while heterotrophs should be more prone to P-limitation. We tested these predictions in artificial food webs studying the competitive success of mixotrophic bacterivores under a range of light intensities and loss rates and under either P- or N-limitation. Under low-light conditions, mixotrophs were more successful than heterotrophs under P-limitation, whereas the heterotrophs were more successful under N-limitation. At higher light intensity, mixotrophs had an advantage over photoautotrophs, due to the acquisition of nutrients ingested with prey. Overall, the effects of the limiting nutrient on the competitive success of mixotrophs were stronger under conditions already unfavorable for mixotrophs (low light). Further, our results suggest that communities dominated by mixotrophs might have low and relatively stable seston C:nutrient ratios. The results presented here supplement existing data well and help to define the ecological niche of mixotrophic protists.}, keywords = {RCC744}, doi = {10.3354/meps11968}, url = {https://www.int-res.com/abstracts/meps/v563/p51-63}, author = {Fischer, R and HA, Giebel and Ptacnik, R} } @article {faucher_impact_2017, title = {Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress}, journal = {Biogeosciences}, volume = {14}, number = {14}, year = {2017}, note = {Publisher: Copernicus GmbH}, month = {jul}, pages = {3603{\textendash}3613}, abstract = {

Abstract. The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO$_\textrm2$, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely \textitEmiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and \textitCoccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.

Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in \textitE. huxleyi and \textitC. pelagicus, while coccoliths of \textitG. oceanica showed a decrease in size only at the highest trace metal concentrations. \textitP. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (\textitP. carterae), intermediate- (\textitE. huxleyi and \textitG. oceanica) and least-tolerant (\textitC. pelagicus) taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.

These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

}, keywords = {RCC1198, RCC1216, RCC1303}, issn = {1726-4170}, doi = {10.5194/bg-14-3603-2017}, url = {https://bg.copernicus.org/articles/14/3603/2017/}, author = {Faucher, Giulia and Hoffmann, Linn and Bach, Lennart T. and Bottini, Cinzia and Erba, Elisabetta and Riebesell, Ulf} } @article {Fischer2017a, title = {Importance of mixotrophic bacterivory can be predicted by light and loss rates}, journal = {Oikos}, volume = {126}, number = {5}, year = {2017}, note = {Publisher: John Wiley \& Sons, Ltd (10.1111) tex.mendeley-tags: RCC744}, month = {may}, pages = {713{\textendash}722}, abstract = {Recent observational studies form oligotrophic waters provide ample evidence that mixotrophic flagellates often account for the bulk of bacterivory. However, we lack a general framework that allows a mechanistic understanding of success of mixotrophs in the competition with heterotrophic bacterivores. This is especially needed for integrating mixotrophy in models of the microbial loop. Based on general tradeoffs linked to the combined resource use in mixotrophs (generalist versus specialist), we propose a concept where mixotrophs are favored by conditions of high light ? low losses, corresponding to the situation found in the surface waters of oligotrophic oceans. Under such conditions, they can achieve positive net growth at very low resource levels, allowing simultaneous competition with specialized protists. Conversely, heterotrophic bacterivores and photoautotrophs should be especially favored in more productive and low-light conditions. We show experimentally that the combined effect of light and loss rates (dilution) predicts the success of mixotrophic bacterivorous flagellates. Moreover, our results suggest that total bacterivory, contrary as seen in the traditional microbial loop concept, has a more intricate coupling to light.}, keywords = {RCC744}, issn = {0030-1299}, doi = {10.1111/oik.03539}, url = {https://doi.org/10.1111/oik.03539}, author = {Fischer, Robert and Giebel, Helge-Ansgar and Hillebrand, Helmut and Ptacnik, Robert} } @article {Marie2017, title = {Improvement of phytoplankton culture isolation using single cell sorting by flow cytometry}, journal = {Journal of Phycology}, volume = {53}, number = {2}, year = {2017}, note = {tex.mendeley-tags: 2016,RCC1008,RCC299,RCC350,RCC4108,RCC4548,RCC4549,RCC4550,RCC4551,RCC4552,RCC4553,RCC4554,RCC4555,RCC4556,RCC4557,RCC4558,RCC4559,RCC4560,RCC4561,RCC4562,RCC4563,RCC4564,RCC4565,RCC4566,RCC4567,RCC4568,RCC4569,RCC4570,RCC4571,RCC4572,RCC4573,RCC4574,RCC4575,RCC4576,RCC4577,RCC4578,RCC4579,RCC4657,RCC4658,RCC4659,RCC4660,RCC4661,RCC4662,RCC4663,RCC4664,RCC4665,RCC4666,RCC90}, month = {apr}, pages = {271{\textendash}282}, keywords = {2016, RCC1008, RCC299, RCC350, RCC4108, RCC4548, RCC4549, RCC4550, RCC4551, RCC4552, RCC4553, RCC4554, RCC4555, RCC4556, RCC4557, RCC4558, RCC4559, RCC4560, RCC4561, RCC4562, RCC4563, RCC4564, RCC4565, RCC4566, RCC4567, RCC4568, RCC4569, RCC4570, RCC4571, RCC4572, RCC4573, RCC4574, RCC4575, RCC4576, RCC4577, RCC4578, RCC4579, RCC4657, RCC4658, RCC4659, RCC4660, RCC4661, RCC4662, RCC4663, RCC4664, RCC4665, RCC4666, RCC90}, issn = {00223646}, doi = {10.1111/jpy.12495}, url = {http://doi.wiley.com/10.1111/jpy.12495}, author = {Marie, Dominique and Le Gall, Florence and Edern, Roseline and Gourvil, Priscillia and Vaulot, Daniel}, editor = {Valentin, K.} } @article {Weynberg2017, title = {Marine prasinoviruses and their tiny plankton hosts : A review}, journal = {Viruses}, number = {March}, year = {2017}, note = {tex.mendeley-tags: 2017,RCC,rcc1105,rcc299,rcc809}, pages = {1{\textendash}20}, abstract = {Viruses play a crucial role in the marine environment, promoting nutrient recycling and biogeochemical cycling and driving evolutionary processes. Tiny marine phytoplankton called prasinophytes are ubiquitous and significant contributors to global primary production and biomass. A number of viruses (known as prasinoviruses) that infect these important primary producers have been isolated and characterised over the past decade. Here we review the current body of knowledge about prasinoviruses and their interactions with their algal hosts. Several genes, including those encoding for glycosyltransferases, methyltransferases and amino acid synthesis enzymes, which have never been identified in viruses of eukaryotes previously, have been detected in prasinovirus genomes. The host organisms are also intriguing; most recently, an immunity chromosome used by a prasinophyte in response to viral infection was discovered. In light of such recent, novel discoveries, we discuss why the cellular simplicity of prasinophytes makes for appealing model host organism{\textendash}virus systems to facilitate focused and detailed investigations into the dynamics of marine viruses and their intimate associations with host species. We encourage the adoption of the prasinophyte Ostreococcus and its associated viruses as a model host{\textendash}virus system for examination of cellular and molecular processes in the marine environment.}, keywords = {2017, host interactions, marine virus ecology, rcc, RCC1105, RCC299, RCC809, virus, virus-driven evolution, virus{\textendash}host interactions}, issn = {1999-4915}, doi = {10.3390/v9030043}, author = {Weynberg, Karen D and Allen, Michael J and Wilson, William H} } @article {Yoo2017a, title = {Mixotrophy in the marine red-tide cryptophyte Teleaulax amphioxeia and ingestion and grazing impact of cryptophytes on natural populations of bacteria in Korean coastal waters}, journal = {Harmful Algae}, volume = {68}, number = {May 2005}, year = {2017}, note = {Publisher: Elsevier B.V. tex.mendeley-tags: RCC1086}, pages = {105{\textendash}117}, abstract = {Cryptophytes are ubiquitous and one of the major phototrophic components in marine plankton communities. They often cause red tides in the waters of many countries. Understanding the bloom dynamics of cryptophytes is, therefore, of great importance. A critical step in this understanding is unveiling their trophic modes. Prior to this study, several freshwater cryptophyte species and marine Cryptomonas sp. and Geminifera cryophila were revealed to be mixotrophic. The trophic mode of the common marine cryptophyte species, Teleaulax amphioxeia has not been investigated yet. Thus, to explore the mixotrophic ability of T. amphioxeia by assessing the types of prey species that this species is able to feed on, the protoplasms of T. amphioxeia cells were carefully examined under an epifluorescence microscope and a transmission electron microscope after adding each of the diverse prey species. Furthermore, T. amphioxeia ingestion rates heterotrophic bacteria and the cyanobacterium Synechococcus sp. were measured as a function of prey concentration. Moreover, the feeding of natural populations of cryptophytes on natural populations of heterotrophic bacteria was assessed in Masan Bay in April 2006. This study reported for the first time, to our knowledge, that T. amphioxeia is a mixotrophic species. Among the prey organisms offered, T. amphioxeia fed only on heterotrophic bacteria and Synechococcus sp. The ingestion rates of T. amphioxeia on heterotrophic bacteria or Synechococcus sp. rapidly increased with increasing prey concentrations up to 8.6 {\texttimes} 106 cells ml-1, but slowly at higher prey concentrations. The maximum ingestion rates of T. amphioxeia on heterotrophic bacteria and Synechococcus sp. reached 0.7 and 0.3 cells predator-1 h-1, respectively. During the field experiments, the ingestion rates and grazing coefficients of cryptophytes on natural populations of heterotrophic bacteria were 0.3{\textendash}8.3 cells predator-1 h-1 and 0.012{\textendash}0.033 d-1, respectively. Marine cryptophytes, including T. amphioxeia, are known to be favorite prey species for many mixotrophic and heterotrophic dinoflagellates and ciliates. Cryptophytes, therefore, likely play important roles in marine food webs and may exert a considerable potential grazing impact on the populations of marine bacteria.}, keywords = {Bloom, Flagellate, Grazing impact, Predator-prey relationship, RCC1086, Red tide}, issn = {18781470}, doi = {10.1016/j.hal.2017.07.012}, url = {http://dx.doi.org/10.1016/j.hal.2017.07.012}, author = {Yoo, Yeong Du and Seong, Kyeong Ah and Jeong, Hae Jin and Yih, Wonho and Rho, Jung Rae and Nam, Seung Won and Kim, Hyung Seop} } @article {Balzano2017c, title = {Morphological and genetic diversity of Beaufort Sea diatoms with high contributions from the Chaetoceros neogracilis species complex}, journal = {Journal of Phycology}, volume = {53}, number = {1}, year = {2017}, note = {tex.mendeley-tags: RCC1984,RCC1985,RCC1986,RCC1988,RCC1989,RCC1990,RCC1991,RCC1992,RCC1993,RCC1995,RCC1997,RCC1999,RCC2000,RCC2002,RCC2003,RCC2004,RCC2005,RCC2006,RCC2008,RCC2010,RCC2011,RCC2012,RCC2014,RCC2016,RCC2017,RCC2021,RCC2037,RCC2038,RCC2039,RCC2042,RCC2043,RCC2261,RCC2262,RCC2263,RCC2264,RCC2265,RCC2266,RCC2267,RCC2268,RCC2269,RCC2270,RCC2272,RCC2273,RCC2274,RCC2275,RCC2276,RCC2277,RCC2278,RCC2279,RCC2280,RCC2281,RCC2282,RCC2318,RCC2506,RCC2517,RCC2520,RCC2521,RCC2522}, month = {feb}, pages = {161{\textendash}187}, abstract = {Seventy-five diatom strains isolated from the Beaufort Sea (Canadian Arctic) in the summer of 2009 were characterized by light and electron microscopy (SEM and TEM), as well as 18S and 28S rRNA gene sequencing. These strains group into 20 genotypes and 17 morphotypes and are affiliated with the genera Arcocellulus, Attheya, Chaetoceros, Cylindrotheca, Eucampia, Nitzschia, Porosira, Pseudo-nitzschia, Shionodiscus, Thalassiosira, and Synedropsis. Most of the species have a distribution confined to the northern/polar area. Chaetoceros neogracilis and Chaetoceros gelidus were the most represented taxa. Strains of C. neogracilis were morphologically similar and shared identical 18S rRNA gene sequences, but belonged to four distinct genetic clades based on 28S rRNA, ITS-1 and ITS-2 phylogenies. Secondary structure prediction revealed that these four clades differ in hemi-compensatory base changes (HCBCs) in paired positions of the ITS-2, suggesting their inability to interbreed. Reproductively isolated C. neogracilis genotypes can thus co-occur in summer phytoplankton communities in the Beaufort Sea. C. neogracilis generally occurred as single cells but also formed short colonies. It is phylogenetically distinct from an Antarctic species, erroneously identified in some previous studies as C. neogracilis, but named here as Chaetoceros sp. This work provides taxonomically validated sequences for 20 Arctic diatom taxa, which will facilitate future metabarcoding studies on phytoplankton in this region.}, keywords = {RCC1984, RCC1985, RCC1986, RCC1988, RCC1989, RCC1990, RCC1991, RCC1992, RCC1993, RCC1995, RCC1997, RCC1999, RCC2000, RCC2002, RCC2003, RCC2004, RCC2005, RCC2006, RCC2008, RCC2010, RCC2011, RCC2012, RCC2014, RCC2016, RCC2017, RCC2021, RCC2037, RCC2038, RCC2039, RCC2042, RCC2043, RCC2261, RCC2262, RCC2263, RCC2264, RCC2265, RCC2266, RCC2267, RCC2268, RCC2269, RCC2270, RCC2272, RCC2273, RCC2274, RCC2275, RCC2276, RCC2277, RCC2278, RCC2279, RCC2280, RCC2281, RCC2282, RCC2318, RCC2506, RCC2517, RCC2520, RCC2521, RCC2522}, issn = {00223646}, doi = {10.1111/jpy.12489}, url = {http://doi.wiley.com/10.1111/jpy.12489}, author = {Balzano, Sergio and Percopo, Isabella and Siano, Raffaele and Gourvil, Priscillia and Chanoine, M{\'e}lanie and Marie, Dominique and Vaulot, Daniel and Sarno, Diana}, editor = {Wood, M.} } @article {Steele2017, title = {Occurrence of chlorophyll allomers during virus-induced mortality and population decline in the ubiquitous picoeukaryote Ostreococcus tauri}, journal = {Environmental Microbiology}, volume = {in press}, year = {2017}, note = {ISBN: 3907122046 tex.mendeley-tags: RCC745}, month = {nov}, pages = {1{\textendash}41}, abstract = {Phytoplankton have been shown to harbour a diversity of hydrocarbonoclastic bacteria (HCB), yet it is not understood how these phytoplankton-associated HCB would respond in the event of an oil spill at sea. Here, we assess the diversity and dynamics of the bacterial community associated with a natural population of marine phytoplankton under oil spill-simulated conditions, and compare it to that of the free-living (non phytoplankton-associated) bacterial community. Whilst the crude oil severely impacted the phytoplankton population and was likely conducive to marine oil snow (MOS) formation, analysis of the MiSeq-derived 16S rRNA data revealed dramatic and differential shifts in the oil-amended communities that included blooms of recognised HCB (e.g. Thalassospira, Cycloclasticus), including putative novel phyla, as well as other groups with previously unqualified oil-degrading potential (Olleya, Winogradskyella, and members of the inconspicuous BD7-3 phylum). Notably, the oil biodegradation potential of the phytoplankton-associated community exceeded that of the free-living community, and it showed a preference to degrade substituted and non-substituted polycyclic aromatic hydrocarbons. Our study provides evidence of compartmentalisation of hydrocarbon-degrading capacity in the marine water column, wherein HCB associated with phytoplankton are better tuned to degrading crude oil hydrocarbons than that by the community of planktonic free-living bacteria.}, keywords = {biodegradation, crude oil, eukaryotic phytoplankton, hydrocarbon-degrading bacteria (HCB), marine environment, micro- algae, RCC745}, issn = {14622912}, doi = {10.1111/1462-2920.13980}, url = {http://doi.wiley.com/10.1111/1462-2920.13980}, author = {Steele, Deborah J. and Kimmance, Susan A. and Franklin, Daniel J. and Airs, Ruth L.} } @article {Soitamo2017, title = {Photoinhibition in marine picocyanobacteria}, journal = {Physiologia Plantarum}, volume = {161}, number = {1}, year = {2017}, note = {Publisher: John Wiley \& Sons, Ltd (10.1111) tex.mendeley-tags: RCC156,RCC2366,RCC296,RCC407}, month = {sep}, pages = {97{\textendash}108}, abstract = {Marine Synechococcus and Prochlorococcus cyanobacteria have different antenna compositions although they are genetically near to each other, and different strains thrive in very different illumination conditions. We measured growth and photoinhibition of PSII in two low-light and one high-light Prochlorococcus strains and in one Synechococcus strain. All strains were found to be able to shortly utilize moderate or even high light, but the low-light strains bleached rapidly in moderate light. Measurements of photoinhibition in the presence of the antibiotic lincomycin showed that a low-light Prochlorococcus strain was more sensitive than a high-light strain and both were more sensitive than the marine Synechococcus. The action spectrum of photoinhibition showed an increase from blue to ultraviolet wavelengths in all strains, suggesting contribution of manganese absorption to photoinhibition, but blue light caused less photoinhibition in marine cyanobacteria than expected on the basis of earlier results from plants and cyanobacteria. The visible-light part of the action spectrum resembled the absorption spectrum of the organism, suggesting that photosynthetic antenna pigments, especially divinyl chlorophylls, have a more important role as photoreceptors of visible-light photoinhibition in marine cyanobacteria than in other photoautotrophs.}, keywords = {RCC156, RCC2366, rcc296, RCC407}, issn = {0031-9317}, doi = {10.1111/ppl.12571}, url = {https://doi.org/10.1111/ppl.12571}, author = {Soitamo, Arto and Havurinne, Vesa and Tyystj{\"a}rvi, Esa} } @article {Parks2017, title = {Phylogenomics reveals an extensive history of genome duplication in diatoms (Bacillariophyta)}, journal = {American Journal of Botany}, volume = {105}, number = {3}, year = {2017}, note = {tex.mendeley-tags: RCC205,RCC80}, pages = {1{\textendash}18}, keywords = {and, b, c, citation, diatoms, e, gene tree, genome duplication, j, n, nakov, paleopolyploidy, parks m, polyploidy, RCC205, RCC80, ruck, synonymous divergence, t, these authors contributed equally, to this work, wickett}, doi = {10.1101/181115}, author = {Parks, Matthew and Nakov, Teofil and Ruck, Elizabeth and Wickett, Norman J and Alverson, Andrew J and Rice, Ada L and Conservation, Plant and Botanic, Chicago and Glencoe, Garden} } @article {Mackey2017, title = {Physiological and proteomic characterization of light adaptations in marine Synechococcus}, journal = {Environmental Microbiology}, volume = {19}, number = {6}, year = {2017}, note = {tex.mendeley-tags: rcc539,rcc752}, month = {jun}, pages = {2348{\textendash}2365}, keywords = {rcc539, rcc752}, issn = {14622912}, doi = {10.1111/1462-2920.13744}, url = {http://doi.wiley.com/10.1111/1462-2920.13744}, author = {Mackey, Katherine R. M. and Post, Anton F and McIlvin, Matthew R and Saito, Mak A} } @article {Blanc-Mathieu2017, title = {Population genomics of picophytoplankton unveils novel chromosome hypervariability}, journal = {Science Advances}, volume = {3}, number = {7}, year = {2017}, note = {tex.mendeley-tags: RCC1105,RCC1108,RCC1110,RCC1112,RCC1114,RCC1115,RCC1116,RCC1117,RCC1118,RCC1123,RCC1558,RCC1559,RCC1561,RCC299,RCC4221,RCC809}, month = {jul}, pages = {e1700239}, keywords = {RCC1105, RCC1108, RCC1110, RCC1112, RCC1114, RCC1115, RCC1116, RCC1117, RCC1118, RCC1123, RCC1558, RCC1559, RCC1561, RCC299, RCC4221, RCC809}, issn = {2375-2548}, doi = {10.1126/sciadv.1700239}, url = {http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.1700239}, author = {Blanc-Mathieu, Romain and Krasovec, Marc and Hebrard, Maxime and Yau, Sheree and Desgranges, Elodie and Martin, Joel and Schackwitz, Wendy and Kuo, Alan and Salin, Gerald and Donnadieu, Cecile and Desdevises, Yves and Sanchez-Ferandin, Sophie and Moreau, Herv{\'e} and Rivals, Eric and Grigoriev, Igor V. and Grimsley, Nigel and Eyre-Walker, Adam and Piganeau, Gwenael} } @article {Derelle2017, title = {Prasinovirus attack of ostreococcus is furtive by day but savage by night}, journal = {Journal of Virology}, volume = {92}, number = {4}, year = {2017}, note = {tex.mendeley-tags: RCC4221}, month = {nov}, pages = {JVI.01703{\textendash}17}, abstract = {Prasinoviruses are large DNA viruses that infect diverse genera of green microalgae worldwide in aquatic ecosystems, but molecular knowledge of their life-cycles is lacking. Several complete genomes of both these viruses and their marine algal hosts are now available and have been used to show the pervasive presence of these species in microbial metagenomes. We have analysed the life-cycle of OtV5, a lytic virus, using RNA-Seq from 12 time points of healthy or infected Ostreococcus tauri cells over a day/night cycle in culture. In the day, viral gene transcription remained low while host nitrogen metabolism gene transcription was initially strongly repressed for two successive time points before being induced for 8 hours, but in the night viral transcription increased steeply while host nitrogen metabolism genes were repressed and many host functions that are normally reduced in the night appeared to be compensated either by genes expressed from the virus or by increased expression of a subset of 4.4 \% of the host{\textquoteright}s genes. Some host cells lysed progressively during the night, but a larger proportion lysed the following morning. Our data suggest that the life-cycles of algal viruses mirror the diurnal rhythms of their hosts.}, keywords = {accepted 9, mamiellophyceae, ncldv, Ostreococcus, phycodnaviridae, prasinophytes, RCC4221, received 28 september 2017}, issn = {0022-538X}, doi = {10.1128/JVI.01703-17}, url = {http://jvi.asm.org/lookup/doi/10.1128/JVI.01703-17}, author = {Derelle, Evelyne and Yau, Sheree and Moreau, Herv{\'e} and Grimsley, Nigel H.} } @article {Limardo2017, title = {Quantitative biogeography of picoprasinophytes establishes ecotype distributions and significant contributions to marine phytoplankton}, journal = {Environmental Microbiology}, year = {2017}, note = {tex.mendeley-tags: RCC1105,RCC715,RCC716,RCC809}, month = {jun}, keywords = {RCC1105, RCC715, RCC716, RCC809}, issn = {14622912}, doi = {10.1111/1462-2920.13812}, url = {http://doi.wiley.com/10.1111/1462-2920.13812}, author = {Limardo, Alexander J. and Sudek, Sebastian and Choi, Chang Jae and Poirier, Camille and Rii, Yoshimi M. and Blum, Marguerite and Roth, Robyn and Goodenough, Ursula and Church, Matthew J. and Worden, Alexandra Z.} } @article {Dominguez-Martin2017, title = {Quantitative proteomics shows extensive remodeling induced by nitrogen limitation in prochlorococcus marinus SS120}, journal = {mSystems}, volume = {2}, number = {3}, year = {2017}, note = {tex.mendeley-tags: RCC156}, month = {jun}, pages = {e00008{\textendash}17}, abstract = {Prochlorococcus requires the capability to accommodate to environmental changes in order to proliferate in oligotrophic oceans, in particular regarding nitrogen availability. A precise knowledge of the composition and changes in the proteome can yield fundamental insights into such a response. Here we report a detailed proteome analysis of the important model cyanobacterium Prochlorococcus marinus SS120 after treatment with azaserine, an inhibitor of ferredoxin-dependent glutamate synthase (GOGAT), to simulate extreme nitrogen starvation. In total, 1,072 proteins, corresponding to 57\% of the theoretical proteome, were identified{\textemdash}the maximum proteome coverage obtained for any Prochlorococcus strain thus far. Spectral intensity, calibrated quantification by the Hi3 method, was obtained for 1,007 proteins. Statistically significant changes ( P value of {\textexclamdown}0.05) were observed for 408 proteins, with the majority of proteins (92.4\%) downregulated after 8 h of treatment. There was a strong decrease in ribosomal proteins upon azaserine addition, while many transporters were increased. The regulatory proteins P II and PipX were decreased, and the global nitrogen regulator NtcA was upregulated. Furthermore, our data for Prochlorococcus indicate that NtcA also participates in the regulation of photosynthesis. Prochlorococcus responds to the lack of nitrogen by slowing down translation, while inducing photosynthetic cyclic electron flow and biosynthesis of proteins involved in nitrogen uptake and assimilation.}, keywords = {RCC156}, issn = {2379-5077}, doi = {10.1128/mSystems.00008-17}, url = {http://msystems.asm.org/lookup/doi/10.1128/mSystems.00008-17}, author = {Dom{\'\i}nguez-Mart{\'\i}n, Maria Agustina and G{\'o}mez-Baena, Guadalupe and D{\'\i}ez, Jes{\'u}s and L{\'o}pez-Grueso, Maria Jos{\'e} and Beynon, Robert J. and Garc{\'\i}a-Fern{\'a}ndez, Jos{\'e} Manuel}, editor = {Huber, Julie A.} } @article {Roesler2017, title = {Recommendations for obtaining unbiased chlorophyll estimates from in situ chlorophyll fluorometers: A global analysis of WET Labs ECO sensors}, journal = {Limnology and Oceanography: Methods}, volume = {15}, number = {6}, year = {2017}, note = {tex.mendeley-tags: RCC233,RCC42,RCC834}, pages = {572{\textendash}585}, abstract = {Chlorophyll fluorometers provide the largest in situ global data set for estimating phytoplankton biomass because of their ease of use, size, power consumption, and relatively low price. While in situ chlorophyll a (Chl) fluorescence is proxy for Chl a concentration, and hence phytoplankton biomass, there exist large natural variations in the relationship between in situ fluorescence and extracted Chl a concentration. Despite this large natural variability, we present here a global validation data set for the WET Labs Environmental Characterization Optics (ECO) series chlorophyll fluorometers that suggests a factor of 2 overestimation in the factory calibrated Chl a estimates for this specific manufacturer and series of sensors. We base these results on paired High Pressure Liquid Chromatography (HPLC) and in situ fluorescence match ups for which non-photochemically quenched fluorescence observations were removed. Additionally, we examined matchups between the factory-calibrated in situ fluorescence and estimates of chlorophyll concentration determined from in situ radiometry, absorption line height, NASA{\textquoteright}s standard ocean color algorithm as well as laboratory calibrations with phytoplankton monocultures spanning diverse species that support the factor of 2 bias. We therefore recommend the factor of 2 global bias correction be applied for the WET Labs ECO sensors, at the user level, to improve the global accuracy of chlorophyll concentration estimates and products derived from them. We recommend that other fluorometer makes and models should likewise undergo global analyses to identify potential bias in factory calibration.}, keywords = {RCC233, RCC42, RCC834}, issn = {15415856}, doi = {10.1002/lom3.10185}, author = {Roesler, Collin and Uitz, Julia and Claustre, Herv{\'e} and Boss, Emmanuel and Xing, Xiaogang and Organelli, Emanuele and Briggs, Nathan and Bricaud, Annick and Schmechtig, Catherine and Poteau, Antoine and D{\textquoteright}Ortenzio, Fabrizio and Ras, Josephine and Drapeau, Susan and Ha{\"e}ntjens, Nils and Barbieux, Marie} } @article {Andersen2017, title = {Rediscovery of the Ochromonas type species Ochromonas triangulata (Chrysophyceae) from its type locality (Lake Veysove, Donetsk region, Ukraine)}, journal = {Phycologia}, volume = {56}, number = {6}, year = {2017}, note = {tex.ids= Andersen2017a tex.mendeley-tags: 2017,RCC21}, pages = {591{\textendash}604}, abstract = {Ochromonas triangulata, the type species for a genus with over 125 taxa, was collected for only the second time, again from the type locality. Cell morphology, cell division, palmelloid stage and cyst structure generally agreed with the original description. Molecular phylogenetic analysis based on the 18S rRNA gene revealed 13 clades of Ochromonas-like flagellates as well as the clade represented by our O. triangulata strain and the nearly identical strain RCC-21/AC025. We also conducted a concatenated analysis using the 18S rRNA and the rbcL genes, and we recovered the same 14 clades. One clade, containing strains CCAP 933/27 and CCMP1861, previously named Ochromonas tuberculata, was re-identified as Chrysastrella paradoxa and Chrysastrella breviappendiculata, respectively. One clade included the Poterioochromonas strains but we were unable to convincingly connect species names to the strains because authentic strains were unknown or not examined. Organisms in the clade that included the well-known Ochromonas danica were assigned to Chlorochromonas. The generic name Melkoniania gen. nov. was proposed for one distinct clade of marine flagellates. These changes addressed some of the issues associated with the polyphyletic Ochromonas sensu lato but many problems remained.}, keywords = {2017, RCC21}, issn = {0031-8884}, doi = {10.2216/17-15.1}, url = {http://www.phycologia.org/doi/10.2216/17-15.1}, author = {Andersen, Robert A. and Graf, Louis and Malakhov, Yuriy and Yoon, Hwan Su} } @article {Arias2017, title = {Removal and biodegradation of phenanthrene, fluoranthene and pyrene by the marine algae rhodomonas baltica enriched from north atlantic coasts}, journal = {Bulletin of Environmental Contamination and Toxicology}, volume = {98}, number = {3}, year = {2017}, note = {tex.mendeley-tags: RCC350}, pages = {392{\textendash}399}, abstract = {This study is focused on the removal, accumulation and degradation of three environmental ubiquitous polycyclic aromatic hydrocarbons (PAHs), phenanthrene (PHE), fluoranthene (FLA) and pyrene (PYR), by the marine alga Rhodomonas baltica enriched from the English Channel. After separation, purification and culture in several phases, R. baltica was exposed to PAH concentrations that are frequently encountered in the field in several anthropized environments. The results showed that R. baltica can grow under PAH stress, efficiently remove up to 70\% of these compounds from the medium by 216 h of culture and selectively bioaccumulate PAHs by their hydrophobicity. Between PHE, FLA and PYR, phenanthrene was the compound with higher degradation rates throughout incubation. The equilibrium partitioning theoretical approach showed that physico-chemical partitioning, rather than active bioconcentration, was the major factor governing the bioaccumulation, outlying a potential application in decontamination processes for this species.}, keywords = {RCC350}, issn = {1432-0800}, doi = {10.1007/s00128-016-1967-4}, url = {https://doi.org/10.1007/s00128-016-1967-4}, author = {Arias, Andr{\'e}s H and Souissi, Anissa and Glippa, Olivier and Roussin, Marion and Dumoulin, David and Net, Sopheak and Ouddane, Baghdad and Souissi, Sami} } @article {Cuvelier2017, title = {Responses of the picoprasinophyte Micromonas commoda to light and ultraviolet stress}, journal = {PLOS ONE}, volume = {12}, number = {3}, year = {2017}, note = {ISBN: 1111111111 tex.mendeley-tags: RCC299}, month = {mar}, pages = {e0172135}, keywords = {RCC299}, issn = {1932-6203}, doi = {10.1371/journal.pone.0172135}, url = {http://dx.plos.org/10.1371/journal.pone.0172135}, author = {Cuvelier, Marie L and Guo, Jian and Ortiz, Alejandra C. and van Baren, Marijke J. and Tariq, Muhammad Akram and Partensky, Fr{\'e}d{\'e}ric and Worden, Alexandra Z}, editor = {Cockshutt, Amanda M.} } @article {Simon2017, title = {Revision of the genus micromonas manton et parke (chlorophyta, mamiellophyceae), of the type species m. pusilla (butcher) manton \& parke and of the species m. commoda van baren, bachy and worden and description of two new species based on the genetic}, journal = {Protist}, volume = {168}, number = {5}, year = {2017}, note = {tex.mendeley-tags: 2017,RCC1109,RCC114,RCC2306,RCC2308,RCC299,RCC372,RCC373,RCC418,RCC434,RCC447,RCC448,RCC449,RCC450,RCC451,RCC461,RCC465,RCC472,RCC497,RCC498,RCC570,RCC629,RCC647,RCC658,RCC676,RCC692,RCC746,RCC803,RCC804,RCC805,RCC806,RCC807,RCC808,RCC828,RCC829,RCC830,RCC831,RCC833,RCC834,RCC835,RCC836,sbr?hyto$_\textrmd$ipo}, month = {nov}, pages = {612{\textendash}635}, keywords = {2017, ASSEMBLE, rcc, RCC1109, RCC114, RCC2306, RCC2308, RCC299, RCC372, RCC373, RCC418, RCC434, RCC447, RCC448, RCC449, RCC450, RCC451, RCC461, RCC465, RCC472, RCC497, RCC498, RCC570, RCC629, RCC647, RCC658, RCC676, RCC692, RCC746, RCC803, RCC804, RCC805, RCC806, RCC807, RCC808, RCC828, RCC829, RCC830, RCC831, RCC833, RCC834, RCC835, RCC836, SBR$_\textrmP$hyto$_\textrmD$IPO, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto$_\textrmd$ipo}, issn = {14344610}, doi = {10.1016/j.protis.2017.09.002}, url = {http://linkinghub.elsevier.com/retrieve/pii/S1434461017300780}, author = {Simon, Nathalie and Foulon, Elodie and Grulois, Daphne and Six, Christophe and Desdevises, Yves and Latimier, Marie and Le Gall, Florence and Tragin, Margot and Houdan, Aude and Derelle, Evelyne and Jouenne, Fabien and Marie, Dominique and Le Panse, Sophie and Vaulot, Daniel and Marin, Birger} } @article {Riou2017, title = {Specificity re-evaluation of oligonucleotide probes for the detection of marine picoplankton by tyramide signal amplification-fluorescent in situ hybridization}, journal = {Frontiers in Microbiology}, volume = {8}, number = {May}, year = {2017}, note = {tex.mendeley-tags: RCC257}, month = {may}, pages = {854}, abstract = {Oligonucleotide probes are increasingly being used to characterize natural microbial assemblages by Tyramide Signal Amplification-Fluorescent in situ Hybridization (TSA-FISH, or CAtalysed Reporter Deposition CARD-FISH). In view of the fast-growing rRNA databases, we re-evaluated the in silico specificity of eleven bacterial and eukaryotic probes and competitor frequently used for the quantification of marine picoplankton. We performed tests on cell cultures to decrease the risk for non-specific hybridization, before they are used on environmental samples. The probes were confronted to recent databases and hybridization conditions were tested against target strains matching perfectly with the probes, and against the closest non-target strains presenting one to four mismatches. We increased the hybridization stringency from 55\% to 65\% formamide for the Eub338+EubII+EubIII probe mix to be specific to the Eubacteria domain. In addition, we found that recent changes in the Gammaproteobacteria classification decreased the specificity of Gam42a probe, and that the Roseo536R and Ros537 probes were not specific to, and missed part of the Roseobacter clade. Changes in stringency conditions were important for bacterial probes; these induced respectively a significant increase, in Eubacteria and Roseobacter and no significant changes in Gammaproteobacteria concentrations from the investigated natural environment. We confirmed the eukaryotic probes original conditions, and propose the Euk1209+NChlo01+Chlo02 probe mix to target the largest picoeukaryotic diversity. Experiences acquired through these investigations leads us to propose the use of seven steps protocol for complete FISH probe specificity check-up to improve data quality in environmental studies.}, keywords = {CARD-FISH, Eukaryota, oligonucleotide, PROBES, Prokaryote, RCC257, specificity, TSA-FISH}, issn = {1664-302X}, doi = {10.3389/fmicb.2017.00854}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2017.00854/full}, author = {Riou, Virginie and P{\'e}riot, Marine and Biegala, Isabelle C.} } @article {Demory2017, title = {Temperature is a key factor in Micromonas{\textendash}virus interactions}, journal = {The ISME Journal}, volume = {11}, number = {3}, year = {2017}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: 2017,RCC4229,RCC4253,RCC4265,RCC451,RCC829,RCC834,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, month = {mar}, pages = {601{\textendash}612}, abstract = {The genus Micromonas comprises phytoplankton that show among the widest latitudinal distributions on Earth, and members of this genus are recurrently infected by prasinoviruses in contrasted thermal ecosystems. In this study, we assessed how temperature influences the interplay between the main genetic clades of this prominent microalga and their viruses. The growth of three Micromonas strains (Mic-A, Mic-B, Mic-C) and the stability of their respective lytic viruses (MicV-A, MicV-B, MicV-C) were measured over a thermal range of 4{\textendash}32.5 {\textdegree}C. Similar growth temperature optima (Topt) were predicted for all three hosts but Mic-B exhibited a broader thermal tolerance than Mic-A and Mic-C, suggesting distinct thermoacclimation strategies. Similarly, the MicV-C virus displayed a remarkable thermal stability compared with MicV-A and MicV-B. Despite these divergences, infection dynamics showed that temperatures below Topt lengthened lytic cycle kinetics and reduced viral yield and, notably, that infection at temperatures above Topt did not usually result in cell lysis. Two mechanisms operated depending on the temperature and the biological system. Hosts either prevented the production of viral progeny or maintained their ability to produce virions with no apparent cell lysis, pointing to a possible switch in the viral life strategy. Hence, temperature changes critically affect the outcome of Micromonas infection and have implications for ocean biogeochemistry and evolution.}, keywords = {2017, RCC4229, RCC4253, RCC4265, RCC451, RCC829, RCC834, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, issn = {1751-7362}, doi = {10.1038/ismej.2016.160}, url = {http://dx.doi.org/10.1038/ismej.2016.160 http://www.nature.com/doifinder/10.1038/ismej.2016.160}, author = {Demory, David and Arsenieff, Laure and Simon, Nathalie and Six, Christophe and Rigaut-jalabert, Fabienne and Marie, Dominique and Ge, Pei and Bigeard, Estelle and Jacquet, St{\'e}phan and Sciandra, Antoine and Bernard, Olivier and Rabouille, Sophie and Baudoux, Anne-claire} } @article {VanTol2016, title = {Ubiquitous marine bacterium inhibits diatom cell division}, journal = {The ISME Journal}, volume = {11}, number = {1}, year = {2017}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: 2016,RCC80}, month = {jan}, pages = {31{\textendash}42}, keywords = {2016, RCC80}, issn = {1751-7362}, doi = {10.1038/ismej.2016.112}, url = {http://dx.doi.org/10.1038/ismej.2016.112 http://www.nature.com/doifinder/10.1038/ismej.2016.112}, author = {van Tol, Helena M and Amin, Shady A and Armbrust, E Virginia} } @article {Paerl2016, title = {Use of plankton-derived vitamin B1 precursors, especially thiazole-related precursor, by key marine picoeukaryotic phytoplankton}, journal = {The ISME Journal}, volume = {11}, number = {3}, year = {2017}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: rcc3401,rcc745}, month = {mar}, pages = {753{\textendash}765}, keywords = {rcc3401, RCC745}, issn = {1751-7362}, doi = {10.1038/ismej.2016.145}, url = {http://www.nature.com/doifinder/10.1038/ismej.2016.145}, author = {Paerl, Ryan W and Bouget, Fran{\c c}ois-Yves and Lozano, Jean-Claude and Verg{\'e}, Val{\'e}rie and Schatt, Philippe and Allen, Eric E and Palenik, Brian and Azam, Farooq} } @article {Simmons2016, title = {Abundance and biogeography of picoprasinophyte ecotypes and other phytoplankton in the eastern north pacific ocean}, journal = {Applied and Environmental Microbiology}, volume = {82}, number = {6}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc}, month = {mar}, pages = {1693{\textendash}1705}, abstract = {Eukaryotic algae within the picoplankton size class (<=2 ??m in diameter) are important marine primary producers, but their spatial and ecological distributions are not well characterized. Here, we studied three picoeukaryotic prasinophyte genera and their cyanobacterial counterparts, Prochlorococcus and Synechococcus , during two cruises along a North Pacific transect characterized by different ecological regimes. Picoeukaryotes and Synechococcus reached maximum abundances of 1.44 {\texttimes} 10 5 and 3.37 {\texttimes} 10 5 cells ? ml -1 , respectively, in mesotrophic waters, while Prochlorococcus reached 1.95 {\texttimes} 10 5 cells ? ml -1 in the oligotrophic ocean. Of the picoeukaryotes, Bathycoccus was present at all stations in both cruises, reaching 21,368 {\textpm} 327 18S rRNA gene copies ? ml -1 . Micromonas and Ostreococcus clade OI were detected only in mesotrophic and coastal waters and Ostreococcus clade OII only in the oligotrophic ocean. To resolve proposed Bathycoccus ecotypes, we established genetic distances for 1,104 marker genes using targeted metagenomes and the Bathycoccus prasinos genome. The analysis was anchored in comparative genome analysis of three Ostreococcus species for which physiological and environmental data are available to facilitate data interpretation. We established that two Bathycoccus ecotypes exist, named here BI (represented by coastal isolate Bathycoccus prasinos ) and BII. These share 82\% {\textpm} 6\% nucleotide identity across homologs, while the Ostreococcus spp. share 75\% {\textpm} 8\%. We developed and applied an analysis of ecomarkers to metatranscriptomes sequenced here and published -omics data from the same region. The results indicated that the Bathycoccus ecotypes cooccur more often than Ostreococcus clades OI and OII do. Exploratory analyses of relative transcript abundances suggest that Bathycoccus NRT2.1 and AMT2.2 are high-affinity NO 3 - and low-affinity NH 4 + transporters, respectively, with close homologs in multiple picoprasinophytes. Additionally, in the open ocean, where dissolved iron concentrations were low (0.08 nM), there appeared to be a shift to the use of nickel superoxide dismutases (SODs) from Mn/Fe/Cu SODs closer inshore. Our study documents the distribution of picophytoplankton along a North Pacific ecological gradient and offers new concepts and techniques for investigating their biogeography.}, keywords = {2016, rcc}, issn = {0099-2240}, doi = {10.1128/AEM.02730-15}, url = {http://aem.asm.org/lookup/doi/10.1128/AEM.02730-15}, author = {Simmons, Melinda P. and Sudek, Sebastian and Monier, Adam and Limardo, Alexander J. and Jimenez, Valeria and Perle, Christopher R. and Elrod, Virginia A. and Pennington, J. Timothy and Worden, Alexandra Z.}, editor = {Schloss, P. D.} } @article {Leliaert2016, title = {Chloroplast phylogenomic analyses reveal the deepest-branching lineage of the Chlorophyta, Palmophyllophyceae class. nov.}, journal = {Scientific Reports}, volume = {6}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC15,RCC299}, month = {may}, pages = {25367}, keywords = {2016, RCC15, RCC299}, issn = {2045-2322}, doi = {10.1038/srep25367}, url = {http://www.nature.com/articles/srep25367}, author = {Leliaert, Frederik and Tronholm, Ana and Lemieux, Claude and Turmel, Monique and DePriest, Michael S. and Bhattacharya, Debashish and Karol, Kenneth G. and Fredericq, Suzanne and Zechman, Frederick W. and Lopez-Bautista, Juan M.} } @article {Bolton2016, title = {Decrease in coccolithophore calcification and CO2 since the middle Miocene}, journal = {Nature Communications}, volume = {7}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc}, pages = {10284}, abstract = {Marine algae are instrumental in carbon cycling and atmospheric carbon dioxide (CO2) regulation. One group, coccolithophores, uses carbon to photosynthesize and to calcify, covering their cells with chalk platelets (coccoliths). How ocean acidification influences coccolithophore calcification is strongly debated, and the effects of carbonate chemistry changes in the geological past are poorly understood. This paper relates degree of coccolith calcification to cellular calcification, and presents the first records of size-normalized coccolith thickness spanning the last 14 Myr from tropical oceans. Degree of calcification was highest in the low-pH, high-CO2 Miocene ocean, but decreased significantly between 6 and 4 Myr ago. Based on this and concurrent trends in a new alkenone ep record, we propose that decreasing CO2 partly drove the observed trend via reduced cellular bicarbonate allocation to calcification. This trend reversed in the late Pleistocene despite low CO2, suggesting an additional regulator of calcification such as alkalinity. 1}, keywords = {2016, rcc}, issn = {2041-1723}, doi = {10.1038/ncomms10284}, url = {http://www.nature.com/doifinder/10.1038/ncomms10284}, author = {Bolton, Clara T. and Hern{\'a}ndez-S{\'a}nchez, Mar{\'\i}a T. and Fuertes, Miguel-{\'A}ngel and Gonz{\'a}lez-Lemos, Sa{\'u}l and Abrevaya, Lorena and M{\'e}ndez-Vicente, Ana and Flores, Jos{\'e}-Abel and Probert, Ian and Giosan, Liviu and Johnson, Joel and Stoll, Heather M.} } @article {Edvardsen2016, title = {Diversity and distribution of haptophytes revealed by environmental sequencing and metabarcoding {\textendash} a review}, journal = {Perspectives in Phycology}, volume = {3}, number = {2}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc,sbr?hyto$_\textrmd$ipo}, month = {apr}, pages = {77{\textendash}91}, keywords = {2016, rcc, sbr?hyto$_\textrmd$ipo}, issn = {2198-011X}, doi = {10.1127/pip/2016/0052}, url = {https://dx.doi.org/10.6084/m9.figshare.2759983.v1 http://www.schweizerbart.de/papers/pip/detail/3/85671/Diversity_and_distribution_of_haptophytes_revealed?af=crossref}, author = {Edvardsen, Bente and Egge, Elianne Sirnaes and Vaulot, Daniel} } @article {Ichinomiya2016, title = {Diversity and oceanic distribution of Parmales (Bolidophyceae), a picoplankton group closely related to diatoms}, journal = {The ISME Journal}, volume = {in press}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?ppo}, keywords = {2016, MACUMBA, MicroB3, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, sbr?hyto?ppo}, doi = {10.1038/ismej.2016.38}, author = {Ichinomiya, Mutsuo and Lopes dos Santos, A and Gourvil, Priscillia and Yoshikawa, Shinya and Kamiya, Mitsunobu and Ohki, Kaori and Audic, S and de Vargas, Colomban and Vaulot, Daniel and Kuwata, Akira} } @article {Zheng2016, title = {The geographic impact on genomic divergence as revealed by comparison of nine Citromicrobial genomes}, journal = {Applied and Environmental Microbiology}, volume = {82}, number = {24}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC1878,RCC1885,RCC1897,sbr?hyto?app}, pages = {AEM.02495{\textendash}16}, abstract = {Aerobic anoxygenic phototrophic bacteria (AAPB) are thought to be important players in oceanic carbon and energy cycling in the euphotic zone of the ocean. The genus Citromicrobium , widely found in oligotrophic oceans, is a member of marine alphaproteobacterial AAPB. Nine Citromicrobium strains isolated from the South China Sea, the Mediterranean Sea or the tropical South Atlantic were found to harbor identical 16S rRNA sequences. The sequencing of their genomes revealed high synteny in major regions. Nine genetic islands (GIs), involved mainly in type IV secretion systems, flagellar biosynthesis, prophage and integrative conjugative elements, were identified by a fine scale comparative genomics analysis. These GIs played significant roles in genomic evolution and divergence. Interestingly, the co-existence of two different photosynthetic gene clusters (PGCs) was not only found in the analyzed genomes but also confirmed, for the first time, in environmental samples. The prevalence of the coexistence of two different PGCs may suggest an adaptation mechanism for Citromicrobium members to survive in the oceans. Comparison of genomic characteristics (e.g., GIs, ANI, SNPs and phylogeny) revealed that strains within a marine region shared a similar evolutionary history that was distinct from that of strains isolated from other regions (South China Sea vs Mediterranean Sea). Geographic differences are partly responsible for driving the observed genomic divergences, and allow microbes to evolve through local adaptation. Three Citromicrobium strains isolated from the Mediterranean Sea diverged millions of years ago from other strains, and evolved into a novel group.}, keywords = {2016, RCC1878, RCC1885, RCC1897, sbr?hyto?app}, issn = {0099-2240}, doi = {10.1128/AEM.02495-16}, url = {http://aem.asm.org/lookup/doi/10.1128/AEM.02495-16}, author = {Zheng, Qiang and Liu, Yanting and Jeanthon, Christian and Zhang, Rui and Lin, Wenxin and Yao, Jicheng and Jiao, Nianzhi} } @article {Klouch2016, title = {Historical records from dated sediment cores reveal the multidecadal dynamic of the toxic dinoflagellate Alexandrium minutum in the Bay of Brest (France)}, journal = {FEMS Microbiology Ecology}, volume = {92}, number = {7}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc,sbr?hyto$_\textrmd$ipo}, month = {jul}, pages = {fiw101}, abstract = {The multiannual dynamic of the cyst-forming and toxic marine dinoflagellate Alexandrium minutum was studied over a time scale of about 150 years by a paleoecological approach based on ancient DNA (aDNA) quantification and cyst revivification data obtained from two dated sediment cores of the Bay of Brest (Brittany, France). The first genetic traces of the species presence in the study area dated back to 1873 {\textpm} 6. Specific aDNA could be quantified by a newly-developed real-time PCR assay in the upper core layers, in which the germination of the species (in up to 17-19 year-old sediments) was also obtained. In both cores studied, our quantitative paleogenetic data showed a statistically significant increasing trend in the abundance of A. minutum ITS1 rDNA copies over time, corroborating three decades of local plankton data that have documented an increasing trend in the species cell abundance. By comparison, paleogenetic data of the dinoflagellate Scrippsiella donghaienis did not show a coherent trend between the cores studied, supporting the hypothesis of the existence of a species-specific dynamic of A. minutum in the study area. This work contributes to the development of paleoecological research, further showing its potential for biogeographical, ecological and evolutionary studies on marine microbes.}, keywords = {2016, rcc, sbr?hyto$_\textrmd$ipo}, issn = {1574-6941}, doi = {10.1093/femsec/fiw101}, url = {http://www.ncbi.nlm.nih.gov/pubmed/27162179 https://academic.oup.com/femsec/article-lookup/doi/10.1093/femsec/fiw101}, author = {Klouch, Khadidja Z and Schmidt, Sabine and Andrieux-Loyer, Fran{\c c}oise and Le Gac, Micka{\"e}l and Hervio-Heath, Dominique and Qui-Minet, Zujaila N and Qu{\'e}r{\'e}, Julien and Bigeard, Estelle and Guillou, Laure and Siano, Raffaele}, editor = {Laanbroek, Riks} } @article {Waltman2016, title = {Identifying aspects of the post-transcriptional program governing the proteome of the green alga micromonas pusilla.}, journal = {PloS one}, volume = {11}, number = {7}, year = {2016}, note = {ISBN: 10.1371/journal.pone.0155839 Publisher: Public Library of Science tex.mendeley-tags: 2016,RCC,rcc834}, month = {jan}, pages = {e0155839}, abstract = {Micromonas is a unicellular motile alga within the Prasinophyceae, a green algal group that is related to land plants. This picoeukaryote ({\textexclamdown}2 ??m diameter) is widespread in the marine environment but is not well understood at the cellular level. Here, we examine shifts in mRNA and protein expression over the course of the day-night cycle using triplicated mid-exponential, nutrient replete cultures of Micromonas pusilla CCMP1545. Samples were collected at key transition points during the diel cycle for evaluation using high-throughput LC-MS proteomics. In conjunction, matched mRNA samples from the same time points were sequenced using pair-ended directional Illumina RNA-Seq to investigate the dynamics and relationship between the mRNA and protein expression programs of M. pusilla. Similar to a prior study of the marine cyanobacterium Prochlorococcus, we found significant divergence in the mRNA and proteomics expression dynamics in response to the light:dark cycle. Additionally, expressional responses of genes and the proteins they encoded could also be variable within the same metabolic pathway, such as we observed in the oxygenic photosynthesis pathway. A regression framework was used to predict protein levels from both mRNA expression and gene-specific sequence-based features. Several features in the genome sequence were found to influence protein abundance including codon usage as well as 3{\textquoteright} UTR length and structure. Collectively, our studies provide insights into the regulation of the proteome over a diel cycle as well as the relationships between transcriptional and translational programs in the widespread marine green alga Micromonas.}, keywords = {2016, rcc, RCC834}, issn = {1932-6203}, doi = {10.1371/journal.pone.0155839}, url = {http://dx.doi.org/10.1371/journal.pone.0155839}, author = {Waltman, Peter H and Guo, Jian and Reistetter, Emily Nahas and Purvine, Samuel and Ansong, Charles K and van Baren, Marijke J and Wong, Chee-Hong and Wei, Chia-Lin and Smith, Richard D and Callister, Stephen J and Stuart, Joshua M and Worden, Alexandra Z} } @article {Mincer2016, title = {Methanol production by a broad phylogenetic array of marine phytoplankton.}, journal = {PloS one}, volume = {11}, number = {3}, year = {2016}, note = {Publisher: Public Library of Science tex.mendeley-tags: 2016}, month = {jan}, pages = {e0150820}, abstract = {Methanol is a major volatile organic compound on Earth and serves as an important carbon and energy substrate for abundant methylotrophic microbes. Previous geochemical surveys coupled with predictive models suggest that the marine contributions are exceedingly large, rivaling terrestrial sources. Although well studied in terrestrial ecosystems, methanol sources are poorly understood in the marine environment and warrant further investigation. To this end, we adapted a Purge and Trap Gas Chromatography/Mass Spectrometry (P\&T-GC/MS) method which allowed reliable measurements of methanol in seawater and marine phytoplankton cultures with a method detection limit of 120 nanomolar. All phytoplankton tested (cyanobacteria: Synechococcus spp. 8102 and 8103, Trichodesmium erythraeum, and Prochlorococcus marinus), and Eukarya (heterokont diatom: Phaeodactylum tricornutum, coccolithophore: Emiliania huxleyi, cryptophyte: Rhodomonas salina, and non-diatom heterokont: Nannochloropsis oculata) produced methanol, ranging from 0.8-13.7 micromolar in culture and methanol per total cellular carbon were measured in the ranges of 0.09-0.3\%. Phytoplankton culture time-course measurements displayed a punctuated production pattern with maxima near early stationary phase. Stabile isotope labeled bicarbonate incorporation experiments confirmed that methanol was produced from phytoplankton biomass. Overall, our findings suggest that phytoplankton are a major source of methanol in the upper water column of the world{\textquoteright}s oceans.}, keywords = {2016}, issn = {1932-6203}, doi = {10.1371/journal.pone.0150820}, url = {http://dx.doi.org/10.1371/journal.pone.0150820}, author = {Mincer, Tracy J and Aicher, Athena C} } @article {Engesmo2016, title = {New insights into the morphology and phylogeny of Heterosigma akashiwo (Raphidophyceae), with the description of Heterosigma minor sp. nov .}, journal = {Phycologia}, volume = {55}, number = {3}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc1501,rcc1502}, month = {may}, pages = {279{\textendash}294}, keywords = {2016, rcc1501, rcc1502}, issn = {0031-8884}, doi = {10.2216/15-115.1}, url = {http://www.phycologia.org/doi/10.2216/15-115.1}, author = {Engesmo, Anette and Eikrem, Wenche and Seoane, Sergio and Smith, Kirsty and Edvardsen, Bente and Hofgaard, Antje and Tomas, Carmelo R.} } @article {Rokitta2016, title = {P- and n-depletion trigger similar cellular responses to promote senescence in eukaryotic phytoplankton}, journal = {Frontiers in Marine Science}, volume = {3}, number = {July}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC1217,RCC126}, month = {jun}, keywords = {2016, rcc1217, RCC126}, issn = {2296-7745}, doi = {10.3389/fmars.2016.00109}, url = {http://journal.frontiersin.org/article/10.3389/fmars.2016.00109 http://journal.frontiersin.org/Article/10.3389/fmars.2016.00109/abstract}, author = {Rokitta, Sebastian D. and von Dassow, Peter and Rost, Bj{\"o}rn and John, Uwe} } @article {Amiraux2016, title = {Paradoxical effects of temperature and solar irradiance on the photodegradation state of killed phytoplankton}, journal = {Journal of Phycology}, volume = {52}, number = {3}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc2022}, month = {jun}, pages = {475{\textendash}485}, abstract = {The aim of this paper was to study the effects of temperature and irradiance on the photodegradation state of killed phytoplankton cells. For this purpose, killed cells of the diatom Chaetoceros neogracilis RCC2022 were irradiated (PAR radiations) at 36 and 446 J. s(-1.) m(-2) (for a same cumulative dose of irradiation energy) and at two temperatures (7 and 17{\textdegree}C). Analyses of specific lipid tracers (fatty acids and sterols) revealed that low temperatures and irradiances increased photooxidative damages of monounsaturated lipids (i.e. palmitoleic acid, cholesterol and campesterol). The high efficiency of type II photosensitized degradation processes was attributed to: (i) the relative preservation of the sensitizer (chlorophyll) at low irradiances allowing a longer production of singlet oxygen and (ii) the slow diffusion rate of singlet oxygen through membranes at low temperatures inducing more damages. Conversely, high temperatures and irradiances induced (i) a rapid degradation of the photosensitizer and a loss of singlet oxygen by diffusion outside the membranes (limiting type II photosensitized oxidation), and (ii) intense autoxidation processes degrading unsaturated cell lipids and oxidation products used as photodegradation tracers. Our results may likely explain the paradoxical relationship observed in situ between latitude and photodegradation state of phytoplankton cells. This article is protected by copyright. All rights reserved.}, keywords = {2016, rcc2022}, issn = {00223646}, doi = {10.1111/jpy.12410}, url = {http://www.ncbi.nlm.nih.gov/pubmed/26992328 http://doi.wiley.com/10.1111/jpy.12410}, author = {Amiraux, Remi and Jeanthon, Christian and Vaultier, Fr{\'e}d{\'e}ric and Rontani, Jean-Fran{\c c}ois}, editor = {Mock, T.} } @article {Blanco-Ameijeiras2016, title = {Phenotypic variability in the coccolithophore emiliania huxleyi.}, journal = {PloS one}, volume = {11}, number = {6}, year = {2016}, note = {ISBN: 10.1371/journal.pone.0157697 Publisher: Public Library of Science tex.mendeley-tags: 2016,rcc1212,rcc1215,rcc1216,rcc1228,rcc1238,rcc1255,rcc1258,rcc1259,rcc1731,rcc3553}, month = {jan}, pages = {e0157697}, abstract = {Coccolithophores are a vital part of oceanic phytoplankton assemblages that produce organic matter and calcium carbonate (CaCO3) containing traces of other elements (i.e. Sr and Mg). Their associated carbon export from the euphotic zone to the oceans{\textquoteright} interior plays a crucial role in CO2 feedback mechanisms and biogeochemical cycles. The coccolithophore Emiliania huxleyi has been widely studied as a model organism to understand physiological, biogeochemical, and ecological processes in marine sciences. Here, we show the inter-strain variability in physiological and biogeochemical traits in 13 strains of E. huxleyi from various biogeographical provinces obtained from culture collections commonly used in the literature. Our results demonstrate that inter-strain genetic variability has greater potential to induce larger phenotypic differences than the phenotypic plasticity of single strains cultured under a broad range of variable environmental conditions. The range of variation found in physiological parameters and calcite Sr:Ca highlights the need to reconsider phenotypic variability in paleoproxy calibrations and model parameterizations to adequately translate findings from single strain laboratory experiments to the real ocean.}, keywords = {2016, rcc1212, RCC1215, RCC1216, RCC1228, rcc1238, RCC1255, rcc1258, RCC1259, rcc1731, rcc3553}, issn = {1932-6203}, doi = {10.1371/journal.pone.0157697}, url = {http://dx.doi.org/10.1371/journal.pone.0157697}, author = {Blanco-Ameijeiras, Sonia and Lebrato, Mario and Stoll, Heather M and Iglesias-Rodriguez, Debora and M{\"u}ller, Marius N and M{\'e}ndez-Vicente, Ana and Oschlies, Andreas} } @article {LopesdosSantos2016a, title = {Photosynthetic pigments of oceanic Chlorophyta belonging to prasinophytes clade VII}, journal = {Journal of Phycology}, volume = {52}, number = {1}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc,rcc1124,rcc15,rcc1871,rcc2337,rcc2339,rcc287,rcc3374,rcc3376,rcc3402,rcc719,rcc856,rcc857,rcc996,rcc998,sbr?hyto$_\textrmd$ipo}, pages = {148{\textendash}155}, abstract = {The ecological importance and diversity of pico/ nanoplanktonic algae remains poorly studied in marine waters, in part because many are tiny and without distinctive morphological features. Amongst green algae, Mamiellophyceae such as Micromonas or Bathycoccus are dominant in coastal waters while prasinophytes clade VII, yet not formerly described, appear to be major players in open oceanic waters. The pigment composition of 14 strains representative of different subclades of clade VII was analyzed using a method that improves the separation of loroxanthin and neoxanthin. All the prasinophytes clade VII analyzed here showed a pigment composition similar to that previously reported for RCC287 corresponding to pigment group prasino-2A. However, we detected in addition astaxanthin for which it is the first report in prasinophytes. Among the strains analyzed, the pigment signature is qualitatively similar within subclades A and B. By contrast, RCC3402 from subclade C (Picocystis) lacks loroxanthin, astaxanthin, and antheraxanthin but contains alloxanthin, diatoxanthin, and monadoxanthin that are usually found in diatoms or cryptophytes. For subclades A and B, loroxanthin was lowest at highest light irradiance suggesting a light-harvesting role of this pigment in clade VII as in Tetraselmis.}, keywords = {2016, MACUMBA, rcc, RCC1124, RCC15, RCC1871, RCC2337, RCC2339, RCC287, RCC3374, RCC3376, RCC3402, RCC719, RCC856, RCC857, RCC996, RCC998, RCC?o?dd, SBR$_\textrmP$hyto$_\textrmD$IPO, sbr?hyto$_\textrmd$ipo}, doi = {10.1111/jpy.12376}, author = {Lopes dos Santos, Adriana and Gourvil, Priscillia and Rodriguez-Hernandez, Francisco and Garrido, Jos{\'e} Luis and Vaulot, Daniel} } @article {Tragin2016, title = {Phylogenetic diversity and ecology of green micro algae in marine systems}, journal = {Perspectives in Phycology}, volume = {in press}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc,sbr?hyto$_\textrmd$ipo}, keywords = {2016, ? No DOI found, rcc, sbr?hyto$_\textrmd$ipo}, author = {Tragin, M and Lopes dos Santos, Adriana and Christen, R. and Vaulot, D.} } @article {Stawiarski2016, title = {The physiological response of picophytoplankton to temperature and its model representation}, journal = {Fronitiers in Marine Science}, volume = {3}, number = {164}, year = {2016}, note = {tex.mendeley-tags: rcc162,rcc1677,rcc212,rcc289,rcc296,rcc30,rcc361,rcc438,rcc503}, pages = {1{\textendash}13}, keywords = {chlorophyll a to carbon, chlorophyll a to carbon ratio, Eppley, frontiers in marine science, frontiersin, org, physiological parameterization, phytoplankton growth rates, phytoplankton size scaling, picoeukaryotes, picophytoplankton, ratio, rcc162, rcc1677, rcc212, rcc289, rcc296, rcc30, rcc361, rcc438, rcc503, temperature tolerance, www}, issn = {2296-7745}, doi = {10.3389/fmars.2016.00164}, author = {Stawiarski, Beate and Buitenhuis, Erik T and Qu{\'e}r{\'e}, Corinne Le} } @article {Garrido2016, title = {Pigment variations in Emiliania huxleyi (CCMP370) as a response to changes in light intensity or quality}, journal = {Environmental Microbiology}, volume = {18}, number = {12}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc1255}, month = {dec}, pages = {4412{\textendash}4425}, keywords = {2016, RCC1255}, issn = {14622912}, doi = {10.1111/1462-2920.13373}, url = {http://doi.wiley.com/10.1111/1462-2920.13373}, author = {Garrido, Jos{\'e} L. and Brunet, Christophe and Rodr{\'\i}guez, Francisco} } @article {Percopo2016b, title = {Pseudo-nitzschia arctica sp. nov., a new cold-water cryptic Pseudo-nitzschia species within the P. pseudodelicatissima complex}, journal = {Journal of Phycology}, volume = {52}, number = {2}, year = {2016}, note = {tex.mendeley-tags: RCC2002,RCC2004,RCC2005,RCC2517}, month = {apr}, pages = {184{\textendash}199}, abstract = {A new nontoxic Pseudo-nitzschia species belonging to the P. pseudodelicatissima complex, P. arctica, was isolated from different areas of the Arctic. The erection of P. arctica is mainly supported by molecular data, since the species shares identical ultrastructure with another species in the complex, P. fryxelliana, and represents a new case of crypticity within the genus. Despite their morphological similarity, the two species are not closely related in phylogenies based on LSU, ITS and rbcL. Interestingly, P. arctica is phylogenetically most closely related to P. granii and P. subcurvata, from which the species is, however, morphologically different. P. granii and P. subcurvata lack the central larger interspace which is one of the defining features of the P. pseudodelicatissima complex. The close genetic relationship between P. arctica and the two species P. granii and P. subcurvata is demonstrated by analysis of the secondary structure of ITS2 which revealed no compensatory base changes, two hemi-compensatory base changes, and two deletions in P. arctica with respect to the other two species. These findings emphasize that rates of morphological differentiation, molecular evolution and speciation are often incongruent for Pseudo-nitzschia species, resulting in a restricted phylogenetic value for taxonomic characters used to discriminate species. The description of a new cryptic species, widely distributed in the Arctic and potentially representing an endemic component of the Arctic diatom flora, reinforces the idea of the existence of noncosmopolitan Pseudo-nitzschia species and highlights the need for combined morphological and molecular analyses to assess the distributional patterns of phytoplankton species.}, keywords = {RCC2002, RCC2004, RCC2005, RCC2517}, issn = {00223646}, doi = {10.1111/jpy.12395}, url = {http://doi.wiley.com/10.1111/jpy.12395}, author = {Percopo, Isabella and Ruggiero, Maria Valeria and Balzano, Sergio and Gourvil, Priscillia and Lundholm, Nina and Siano, Raffaele and Tammilehto, Anna and Vaulot, Daniel and Sarno, Diana}, editor = {Mock, T.} } @article {Bendif2016, title = {Recent reticulate evolution in the ecologically dominant lineage of coccolithophores}, journal = {Frontiers in Microbiology}, volume = {7}, number = {May}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC4032,RCC4033,RCC4034,RCC4035,RCC4036,rcc,sbr?hyto}, month = {may}, keywords = {2016, coccolithophores, cyto-nuclear discordance, diversity, Emiliania, evolution, Gephyrocapsa, introgressive hybridization, rcc, RCC4032, RCC4033, RCC4034, RCC4035, RCC4036, Reticulofenestra, sbr?hyto}, issn = {1664-302X}, doi = {10.3389/fmicb.2016.00784}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2016.00784 http://journal.frontiersin.org/Article/10.3389/fmicb.2016.00784/abstract}, author = {Bendif, El Mahdi and Probert, Ian and D{\'\i}az-Rosas, Francisco and Thomas, Daniela and van den Engh, Ger and Young, Jeremy R. and von Dassow, Peter} } @article {Durak2016, title = {A role for diatom-like silicon transporters in calcifying coccolithophores}, journal = {Nature Communications}, volume = {7}, number = {February}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC1130,RCC1303,RCC1453,RCC1456,RCC3432}, pages = {10543}, abstract = {Biomineralisation by marine phytoplankton, such as the silicifying diatoms and calcifying coccolithophores, plays an important role in carbon and nutrient cycling in the oceans. Silicification and calcification are distinct cellular processes with no known common mechanisms. As a result, it is thought that coccolithophores are able to outcompete diatoms in Si-depleted waters, which can contribute to the formation of coccolithophore blooms. Here, we show that an expanded family of diatom-like silicon transporters (SITs) are present in both silicifying and calcifying haptophyte phytoplankton, including some coccolithophores of global ecological importance. We find an essential role for Si in calcification in these coccolithophores, indicating that Si uptake contributes to the very different forms of biomineralisation in diatoms and coccolithophores. However, SITs and the requirement for Si are significantly absent from the highly abundant bloom-forming coccolithophores, such as Emiliania huxleyi. These very different requirements for Si in coccolithophores are likely to have major influence on their competitive interactions with diatoms and other siliceous phytoplankton.}, keywords = {(RCC1130, (RCC1456), 2016, biomineralisation, coccolithophores, Gephyrocapsa oceanica (RCC1303) and Scyphosphaera, haptophytes, RCC1130, RCC1303, RCC1453, RCC1456, RCC3432, silica, TMR5 (RCC3432{\textemdash}Sea of Japan) and PZ241 (RCC1453{\textemdash}Med}, issn = {2041-1723}, doi = {10.1038/ncomms10543}, author = {Durak, Grazyna M and Taylor, Alison R and Probert, Ian and de Vargas, Colomban and Audic, St{\'e}phane and Schroeder, Declan C and Brownlee, Colin and Wheeler, Glen L} } @article {Vannier2016, title = {Survey of the green picoalga Bathycoccus genomes in the global ocean}, journal = {Scientific Reports}, volume = {6}, number = {1}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC1105,RCC715,RCC716,sbr?hyto$_\textrmd$ipo,sbr?hyto?ppo}, month = {dec}, pages = {37900}, keywords = {2016, RCC1105, RCC715, RCC716, sbr?hyto$_\textrmd$ipo, sbr?hyto?ppo}, issn = {2045-2322}, doi = {10.1038/srep37900}, url = {http://www.nature.com/articles/srep37900}, author = {Vannier, Thomas and Leconte, Jade and Seeleuthner, Yoann and Mondy, Samuel and Pelletier, Eric and Aury, Jean-Marc and de Vargas, Colomban and Sieracki, Michael and Iudicone, Daniele and Vaulot, Daniel and Wincker, Patrick and Jaillon, Olivier} } @article {Rosas-Navarro2016, title = {Temperature affects the morphology and calcification of Emiliania huxleyi strains}, journal = {Biogeosciences}, volume = {13}, number = {10}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc1252,rcc1710}, month = {may}, pages = {2913{\textendash}2926}, abstract = {The global warming debate has sparked an unprecedented interest in temperature effects on coccolithophores. The calcification response to temperature changes reported in the literature, however, is ambiguous. The two main sources of this ambiguity are putatively differences in experimental setup and strain specificity. In this study we therefore compare three strains isolated in the North Pacific under identical experimental conditions. Three strains of Emiliania huxleyi type A were grown under non-limiting nutrient and light conditions, at 10, 15, 20 and 25 {\textdegree}C. All three strains displayed similar growth rate versus temperature relationships, with an optimum at 20{\textendash}25 {\textdegree}C. Elemental production (particulate inorganic carbon (PIC), particulate organic carbon (POC), total particulate nitrogen (TPN)), coccolith mass, coccolith size, and width of the tube element cycle were positively correlated with temperature over the sub-optimum to optimum temperature range. The correlation between PIC production and coccolith mass/size supports the notion that coccolith mass can be used as a proxy for PIC production in sediment samples. Increasing PIC production was significantly positively correlated with the percentage of incomplete coccoliths in one strain only. Generally, coccoliths were heavier when PIC production was higher. This shows that incompleteness of coccoliths is not due to time shortage at high PIC production. Sub-optimal growth temperatures lead to an increase in the percentage of malformed coccoliths in a strain-specific fashion. Since in total only six strains have been tested thus far, it is presently difficult to say whether sub-optimal temperature is an important factor causing malformations in the field. The most important parameter in biogeochemical terms, the PIC : POC ratio, shows a minimum at optimum growth temperature in all investigated strains. This clarifies the ambiguous picture featuring in the literature, i.e. discrepancies between PIC : POC{\textendash}temperature relationships reported in different studies using different strains and different experimental setups. In summary, global warming might cause a decline in coccolithophore{\textquoteright}s PIC contribution to the rain ratio, as well as improved fitness in some genotypes due to fewer coccolith malformations.}, keywords = {2016, rcc1252, rcc1710}, issn = {1726-4189}, doi = {10.5194/bg-13-2913-2016}, url = {http://www.biogeosciences.net/13/2913/2016/}, author = {Rosas-Navarro, Anaid and Langer, Gerald and Ziveri, Patrizia} } @article {Lu2016, title = {Transcriptomic profiling of Alexandrium fundyense during physical interaction with or exposure to chemical signals from the parasite Amoebophrya.}, journal = {Molecular ecology}, volume = {25}, number = {6}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC3037}, pages = {1294{\textendash}307}, abstract = {Toxic microalgae have their own pathogens, and understanding the way in which these microalgae respond to antagonistic attacks may provide information about their capacity to persist during harmful algal bloom events. Here, we compared the effects of the physical presence of the parasite Amoebophrya sp. and exposure to waterborne cues from cultures infected with this parasite, on gene expression by the toxic dinoflagellates, Alexandrium fundyense. Compared with control samples, a total of 14,882 Alexandrium genes were differentially expressed over the whole-parasite infection cycle at three different time points (0, 6 and 96 h). RNA sequencing analyses indicated that exposure to the parasite and parasitic waterborne cues produced significant changes in the expression levels of Alexandrium genes associated with specific metabolic pathways. The observed upregulation of genes associated with glycolysis, the tricarboxylic acid cycle, fatty acid β-oxidation, oxidative phosphorylation and photosynthesis suggests that parasite infection increases the energy demand of the host. The observed upregulation of genes correlated with signal transduction indicates that Alexandrium could be sensitized by parasite attacks. This response might prime the defence of the host, as indicated by the increased expression of several genes associated with defence and stress. Our findings provide a molecular overview of the response of a dinoflagellate to parasite infection.}, keywords = {2016, Animals, Dinoflagellida, Dinoflagellida: genetics, Dinoflagellida: parasitology, Gene Expression Profiling, Harmful Algal Bloom, Host-Parasite Interactions, Metabolic Networks and Pathways, Microalgae, Microalgae: genetics, Microalgae: parasitology, Parasites, Parasites: chemistry, RCC3037, RNA, Sequence Analysis, Signal Transduction, Transcriptome}, issn = {1365-294X}, doi = {10.1111/mec.13566}, url = {http://www.ncbi.nlm.nih.gov/pubmed/26841307}, author = {Lu, Yameng and Wohlrab, Sylke and Groth, Marco and Gl{\"o}ckner, Gernot and Guillou, Laure and John, Uwe} } @article {Yau2016, title = {A viral immunity chromosome in the marine picoeukaryote, ostreococcus tauri}, journal = {PLOS Pathogens}, volume = {12}, number = {10}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC299,RCC4221,RCC809}, month = {oct}, pages = {e1005965}, keywords = {2016, RCC299, RCC4221, RCC809}, issn = {1553-7374}, doi = {10.1371/journal.ppat.1005965}, url = {http://dx.plos.org/10.1371/journal.ppat.1005965}, author = {Yau, Sheree and Hemon, Claire and Derelle, Evelyne and Moreau, Herv{\'e} and Piganeau, Gwenael and Grimsley, Nigel}, editor = {Ding, Shou-Wei} } @article {Coutinho2015, title = {Comparative genomics of Synechococcus and proposal of the new genus Parasynechococcus}, journal = {PeerJ}, year = {2015}, note = {tex.mendeley-tags: rcc}, pages = {e{\textendash}1522}, keywords = {rcc}, issn = {2167-8359}, doi = {10.7717/peerj.1522}, author = {Coutinho, Felipe and Tschoeke, Diogo Antonio and Thompson, Fabiano and Thomson, Cristiane} } @article {Supraha2015, title = {Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation}, journal = {Scientific Reports}, volume = {5}, number = {November}, year = {2015}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: 2015,RCC1323,RCC1334}, pages = {16499}, keywords = {2015, RCC1323, RCC1334}, issn = {2045-2322}, doi = {10.1038/srep16499}, url = {http://www.nature.com/articles/srep16499}, author = {{\v S}upraha, Luka and Gerecht, Andrea C. and Probert, Ian and Henderiks, Jorijntje} } @article {Varkey2015, title = {Effects of low temperature on tropical and temperate isolates of marine Synechococcus}, journal = {The ISME Journal}, year = {2015}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: rcc}, pages = {1{\textendash}12}, keywords = {rcc}, issn = {1751-7362}, doi = {10.1038/ismej.2015.179}, url = {http://www.nature.com/doifinder/10.1038/ismej.2015.179}, author = {Varkey, Deepa and Mazard, Sophie and Ostrowski, Martin and Tetu, Sasha G and Haynes, Paul and Paulsen, Ian T} } @article {Schaum2015, title = {Environmental stability affects phenotypic evolution in a globally distributed marine picoplankton}, journal = {The ISME Journal}, year = {2015}, note = {tex.mendeley-tags: oth95,rcc1107,rcc1108,rcc1114,rcc1558,rcc1645,rcc1662,rcc410,rcc422,rcc434,rcc501,rcc675,rcc747,rcc789,rcc809,rcc810}, pages = {1{\textendash}10}, abstract = {Marine phytoplankton can evolve rapidly when confronted with aspects of climate change because of their large population sizes and fast generation times. Despite this, the importance of environment fluctuations, a key feature of climate change, has received little attention{\textemdash}selection experiments with marine phytoplankton are usually carried out in stable environments and use single or few representatives of a species, genus or functional group. Here we investigate whether and by how much environmental fluctuations contribute to changes in ecologically important phytoplankton traits such as C:N ratios and cell size, and test the variability of changes in these traits within the globally distributed species Ostreococcus. We have evolved 16 physiologically distinct lineages of Ostreococcus at stable high CO2 (1031{\textpm}87 ??atm CO2 , SH) and fluctuating high CO2 (1012{\textpm}244 ??atm CO2 , FH) for 400 generations.We find that although both fluctuation and high CO2 drive evolution, FH- evolved lineages are smaller, have reduced C:N ratios and respond more strongly to further increases in CO2 than do SH-evolved lineages. This indicates that environmental fluctuations are an important factor to consider when predicting how the characteristics of future phytoplankton populations will have an impact on biogeochemical cycles and higher trophic levels in marine food webs.}, keywords = {oth95, rcc1107, RCC1108, RCC1114, RCC1558, rcc1645, rcc1662, rcc410, rcc422, RCC434, rcc501, rcc675, rcc747, RCC789, RCC809, rcc810}, issn = {1751-7362}, doi = {10.1038/ismej.2015.102}, url = {http://www.nature.com/doifinder/10.1038/ismej.2015.102}, author = {Schaum, C-Elisa and Rost, Bj{\"o}rn and Collins, Sin{\'e}ad} } @article {Wheeler2015, title = {Evolution of alternative biosynthetic pathways for vitamin C following plastid acquisition in photosynthetic eukaryotes}, journal = {eLife}, volume = {4}, year = {2015}, note = {ISBN: 8196242115 tex.mendeley-tags: RCC299}, pages = {1{\textendash}25}, abstract = {Ascorbic acid (vitamin C) is an enzyme co-factor in eukaryotes that also plays a critical role in protecting photosynthetic eukaryotes against damaging reactive oxygen species derived from the chloroplast. Many animal lineages, including primates, have become ascorbate auxotrophs due to the loss of the terminal enzyme in their biosynthetic pathway, L-gulonolactone oxidase (GULO). The alternative pathways found in land plants and Euglena use a different terminal enzyme, L-galactonolactone dehydrogenase (GLDH). The evolutionary processes leading to these differing pathways and their contribution to the cellular roles of ascorbate remain unclear. Here we present molecular and biochemical evidence demonstrating that GULO was functionally replaced with GLDH in photosynthetic eukaryote lineages following plastid acquisition. GULO has therefore been lost repeatedly throughout eukaryote evolution. The formation of the alternative biosynthetic pathways in photosynthetic eukaryotes uncoupled ascorbate synthesis from hydrogen peroxide production and likely contributed to the rise of ascorbate as a major photoprotective antioxidant.}, keywords = {ascorbate, evolutionary biology, Galdieria, genomics, L-gulonolactone oxidase, plant biology, Porphyra, RCC299, vitamin C}, issn = {2050084X}, doi = {10.7554/eLife.06369}, author = {Wheeler, Glen and Ishikawa, Takahiro and Pornsaksit, Varissa and Smirnoff, Nicholas} } @article {Astorga-Elo2015, title = {Genomic potential for nitrogen assimilation in uncultivated members of Prochlorococcus from an anoxic marine zone}, journal = {The ISME Journal}, volume = {9}, year = {2015}, note = {tex.mendeley-tags: rcc}, pages = {1264{\textendash}1267}, abstract = {Cyanobacteria of the genus Prochlorococcus are the most abundant photosynthetic marine organisms and key factors in the global carbon cycle. The understanding of their distribution and ecological importance in oligotrophic tropical and subtropical waters, and their differentiation into distinct ecotypes, is based on genetic and physiological information from several isolates. Currently, all available Prochlorococcus genomes show their incapacity for nitrate utilization. However, environmental sequence data suggest that some uncultivated lineages may have acquired this capacity. Here we report that uncultivated low-light-adapted Prochlorococcus from the nutrient-rich, low-light, anoxic marine zone (AMZ) of the eastern tropical South Pacific have the genetic potential for nitrate uptake and assimilation. All genes involved in this trait were found syntenic with those present in marine Synechococcus. Genomic and phylogenetic analyses also suggest that these genes have not been aquired recently, but perhaps were retained from a common ancestor, highlighting the basal characteristics of the AMZ lineages within Prochlorococcus.}, keywords = {rcc}, issn = {1751-7362}, doi = {10.1038/ismej.2015.21}, url = {http://www.nature.com/doifinder/10.1038/ismej.2015.21}, author = {Astorga-El{\'o}, Marcia and Ram{\'\i}rez-Flandes, Salvador and DeLong, Edward F and Ulloa, Osvaldo} } @article {Schmidt2015, title = {Guanchochroma wildpretii gen. et spec. nov. (ochrophyta) provides new insights into the diversification and evolution of the algal class synchromophyceae.}, journal = {PloS one}, volume = {10}, number = {7}, year = {2015}, note = {Publisher: Public Library of Science tex.mendeley-tags: rcc}, month = {jan}, pages = {e0131821}, abstract = {A new relative of the chrysophyte genus Chrysopodocystis was found in Tenerife and termed Guanchochroma wildpretii. This unicellular alga was most noticeably discernible from Chrysopodocystis socialis (the only species of this genus) by the presence of a cyst-like stage with a multilayered lorica, which also functions as a dispersal unit and shows secondary wall growth. Secondary expansion of loricae (cell casings not involved in cell division, usually with a more or less pronounced opening) has never been observed previously and marks a unique feature of the new taxon. Plastids are non-randomly distributed within cells of G. wildpretii. 18S rRNA gene analyses identified the two species as sister lineages and placed them in a monophyletic group with the Synchromophyceae, a heterokont algal (Ochrophyta) class characterized by the presence of chloroplast complexes. Yet, neither Chrysopodocystis nor Guanchochroma showed this feature in ultrastructure analyses. Additionally, their 18S rRNA genes possessed distinct inserts, the highest GC-content known for Ochrophyta and exceptionally long branches on the Ochrophyta 18S rDNA phylogenetic tree, suggesting substantially increased substitution rates along their branch compared to Synchromophyceae. Plastid marker data (rbcL) recovered a monophyletic clade of Chrysopodocystis, Guanchochroma and Synchromophyceae as well, yet with lower supports for internal split order due to limited resolution of the marker. Evidence for the sequence of events leading to the formation of the plastid complex of Synchromophyceae still remains ambiguous because of the apparently short timeframe in which they occurred.}, keywords = {rcc}, issn = {1932-6203}, doi = {10.1371/journal.pone.0131821}, url = {http://dx.doi.org/10.1371/journal.pone.0131821}, author = {Schmidt, Maria and Horn, Susanne and Ehlers, Katrin and Wilhelm, Christian and Schnetter, Reinhard} } @article {Baudoux2015, title = {Interplay between the genetic clades of {\textexclamdown}i{\textquestiondown}Micromonas{\textexclamdown}/i{\textquestiondown} and their viruses in the Western English Channel.}, journal = {Environmental microbiology reports}, year = {2015}, note = {tex.mendeley-tags: 2015,rcc,sbr?hyto$_\textrmd$ipo}, month = {jun}, abstract = {The genus Micromonas comprises distinct genetic clades that commonly dominate eukaryotic phytoplankton community from polar to tropical waters. This phytoplankter is also recurrently infected by abundant and genetically diverse prasinoviruses. Here we report on the interplay between prasinoviruses and Micromonas with regards to the genetic diversity of this host. During one year, we monitored the abundance of 3 clades of Micromonas and their viruses in the Western English Channel both in the environment, using clade-specific probes and flow cytometry, and in the laboratory, using clonal strains of Micromonas clades to assay for their viruses by plaque-forming units. We showed that the seasonal fluctuations of Micromonas clades were closely mirrored by the abundances of their corresponding viruses, indicating that the members of Micromonas genus are susceptible to viral infection, regardless of their genetic affiliation. The characterization of 45 viral isolates revealed that Micromonas clades are attacked by specific virus populations, which exhibit distinctive clade specificity, life strategies, and genetic diversity. However, some viruses can also cross-infect different host clades suggesting a mechanism of horizontal gene transfer within Micromonas genus. This study provides novel insights into the impact of viral infection for the ecology and evolution of the prominent phytoplankter Micromonas.}, keywords = {2015, rcc, RCC?o?dd, sbr?hyto$_\textrmd$ipo}, issn = {1758-2229}, doi = {10.1111/1758-2229.12309}, url = {http://www.ncbi.nlm.nih.gov/pubmed/26081716}, author = {Baudoux, A-C and Lebredonchel, H and Dehmer, H and Latimier, M and Edern, R and Rigaut-Jalabert, F and Ge, P and Guillou, L and Foulon, E and Bozec, Y and Cariou, T and Desdevises, Y and Derelle, E and Grimsley, N and Moreau, H and Simon, N} } @article {Simmons2015, title = {Intron invasions trace algal speciation and reveal nearly identical Arctic and Antarctic Micromonas populations.}, journal = {Molecular biology and evolution}, year = {2015}, note = {tex.mendeley-tags: rcc}, month = {may}, abstract = {Spliceosomal introns are a hallmark of eukaryotic genes that are hypothesized to play important roles in genome evolution but have poorly understood origins. Although most introns lack sequence homology to each other, recently new families of spliceosomal introns that are repeated hundreds of times in individual genomes have been discovered in a few organisms. The prevalence and conservation of these introner elements (IEs) or introner-like elements (ILEs) in other taxa, as well as their evolutionary relationships to regular spliceosomal introns, are still unknown. Here, we systematically investigate introns in the widespread marine green alga Micromonas and report new families of IEs, numerous intron presence-absence polymorphisms, and potential intron insertion hot-spots. The new families enabled identification of conserved IE secondary structure features and establishment of a novel general model for repetitive intron proliferation across genomes. Despite shared secondary structure, the IE families from each Micromonas lineage bear no obvious sequence similarity to those in the other lineages, suggesting their appearance is intimately linked with the process of speciation. Two of the new IE families come from an Arctic culture (Micromonas Clade E2) isolated from a polar region where this alga is increasing in abundance due to climate change. The same two families were detected in metagenomic data from Antarctica - a system where Micromonas has never before been reported. Strikingly high identity between the Arctic isolate and Antarctic coding sequences that flank the IEs suggests connectivity between populations in the two polar systems that we postulate occurs through deep-sea currents. Recovery of Clade E2 sequences in North Atlantic Deep Waters beneath the Gulf Stream supports this hypothesis. Our work illuminates the dynamic relationships between an unusual class of repetitive introns, genome evolution, speciation and global distribution of this sentinel marine alga.}, keywords = {rcc}, issn = {1537-1719}, doi = {10.1093/molbev/msv122}, url = {http://mbe.oxfordjournals.org/cgi/content/long/msv122v1}, author = {Simmons, Melinda P and Bachy, Charles and Sudek, Sebastian and van Baren, Marijke J and Sudek, Lisa and Ares, Manuel and Worden, Alexandra Z} } @article {Bendif2015, title = {Morphological and phylogenetic characterization of new gephyrocapsa isolates suggests introgressive hybridization in the Emiliania/Gephyrocapsa complex (haptophyta)}, journal = {Protist}, volume = {166}, number = {3}, year = {2015}, note = {tex.mendeley-tags: 2015,RCC1281,RCC1282,RCC1284,RCC1286,RCC1292,RCC1300,RCC1305,RCC1307,RCC1316,RCC1317,RCC1318,RCC1319,RCC1320,RCC1562,RCC1839,RCC3370,RCC3862,RCC3898,rcc}, pages = {323{\textendash}336}, abstract = {The coccolithophore genus Gephyrocapsa contains a cosmopolitan assemblage of pelagic species, including the bloom-forming Gephyrocapsa oceanica, and is closely related to the emblematic coccolithophore Emiliania huxleyi within the No{\"e}laerhabdaceae. These two species have been extensively studied and are well represented in culture collections, whereas cultures of other species of this family are lacking. We report on three new strains of Gephyrocapsa isolated into culture from samples from the Chilean coastal upwelling zone using a novel flow cytometric single-cell sorting technique. The strains were characterized by morphological analysis using scanning electron microscopy and phylogenetic analysis of 6 genes (nuclear 18S and 28S rDNA, plastidial 16S and tufA, and mitochondrial cox1 and cox3 genes). Morphometric features of the coccoliths indicate that these isolates are distinct from G. oceanica and best correspond to G. muellerae. Surprisingly, both plastidial and mitochondrial gene phylogenies placed these strains within the E. huxleyi clade and well separated from G. oceanica isolates, making Emiliania appear polyphyletic. The only nuclear sequence difference, 1bp in the 28S rDNA region, also grouped E. huxleyi with the new Gephyrocapsa isolates and apart from G. oceanica. Specifically, the G. muellerae morphotype strains clustered with the mitochondrial β clade of E. huxleyi, which, like G. muellerae, has been associated with cold (temperate and sub-polar) waters. Among putative evolutionary scenarios that could explain these results we discuss the possibility that E. huxleyi is not a valid taxonomic unit, or, alternatively the possibility of past hybridization and introgression between each E. huxleyi clade and older Gephyrocapsa clades. In either case, the results support the transfer of Emiliania to Gephyrocapsa. These results have important implications for relating morphological species concepts to ecological and evolutionary units of diversity.}, keywords = {2015, coccolithophores, Emiliania huxleyi, Gephyrocapsa muellerae, Gephyrocapsa oceanica, hybridization, phylogeny., rcc, RCC1281, RCC1282, RCC1284, RCC1286, RCC1292, RCC1300, RCC1305, RCC1307, RCC1316, RCC1317, RCC1318, RCC1319, RCC1320, RCC1562, RCC1839, RCC3370, RCC3862, RCC3898, species concept}, issn = {14344610}, doi = {10.1016/j.protis.2015.05.003}, url = {http://www.sciencedirect.com/science/article/pii/S1434461015000243}, author = {Bendif, El Mahdi and Probert, Ian and Young, Jeremy R. and von Dassow, Peter} } @article {Potvin2015, title = {Morphology , molecular phylogeny , and pigment characterization of a novel phenotype of the dinoflagellate genus Pelagodinium from Korean waters}, journal = {Algae}, volume = {30}, number = {3}, year = {2015}, note = {tex.mendeley-tags: rcc}, pages = {183{\textendash}195}, abstract = {The dinoflagellate genus Pelagodinium is genetically classified in distinct sub-clades and subgroups. However, it is dif- ficult to determine whether this genetic diversity represents intra- or interspecific divergence within the genus since only the morphology of the type strain of the genus Pelagodinium, Pelagodinium bei, is available. An isolate associated with the genus Pelagodinium from Shiwha Bay, Korea, was recently cultured. This isolate formed a subgroup with 3 to 4 strains from the Atlantic Ocean, Mediterranean Sea, and Indian Ocean. This subgroup was distinct from the subgroup contain- ing P. bei. The morphology of the isolate was analyzed using optical and scanning electron microscopy and was almost identical to that of P. bei except that this isolate had two series of amphiesmal vesicles (AVs) in the cingulum, unlike P. bei that has one series. When the pigment compositions of the isolate and P. bei were analyzed using high-performance liquid chromatography, these two strains had peridinin as a major accessory pigment and their pigment compositions were almost identical. In addition, the swimming behaviors of these two strains were very similar. The re-examination of the type culture of P. bei revealed two series in the cingulum as for the isolate. The new findings on the number of series of AVs in the cingulum, the pigment composition, and the swimming behaviors suggest that P. bei and the isolate may be conspecific despite their association to genetically different subgroups. This study provides a basis to further understand the molecular classification within Pelagodinium combining genetic, morphological, pigment, and behavioral data.}, keywords = {foraminifera, gymnodinium bei, pelagic symbiont, rcc, suessiaceae, suessiales}, doi = {10.4490/algae.2015.30.3.183}, author = {Potvin, {\'E}ric and Jeong, Hae Jin and Kang, Nam Seon and Noh, Jae Hoon and Yang, Eun Jin} } @article {Kamikawa2015, title = {Multiple losses of photosynthesis in Nitzschia (Bacillariophyceae)}, journal = {Phycological Research}, volume = {63}, year = {2015}, note = {tex.mendeley-tags: rcc}, pages = {19{\textendash}28}, abstract = {In order to obtain insights into the evolution of colorless (apochlorotic) diatoms, we investigated newly established apochlorotic strains of Nitzschia spp. using light and electron microscopy and molecular phylogenetic analyses. Fluores- cence microscopic observations demonstrated that the apochlorotic diatoms lack chlorophylls. Transmission electron microscopy of two apochlorotic strains also demonstrated that their plastids lacked thylakoids; instead, having four- membrane-bound organelles without thylakoids, similar to nonphotosynthetic plastid remnants. From the apochlorotic strains, we also found plastid small subunit rRNA genes that were unusually long branched in phylogenetic analyses, as observed in other nonphotosynthetic plastids. Molecular phylogenetic analysis of the nucleus-encoded large subunit rRNA genes showed eight distinct lineages for apochlo- rotic diatoms. The eight apochlorotic lineages were not monophyletic, suggesting that the loss of photosynthesis took place multiple times independently within Nitzschia. Several diatoms, including Nitzschia spp., are mixotrophic, which is an expected mode of nutrition that would help explain the evolutionary switch from a photosynthetic lifestyle to a heterotrophic lifestyle. Key}, keywords = {apochlorotic diatoms, genetic diversity, large subunit rrna, molecular phylogenetic analysis, nonphotosynthetic plastids, plastid 16s rrna, rcc}, issn = {13220829}, doi = {10.1111/pre.12072}, url = {http://doi.wiley.com/10.1111/pre.12072}, author = {Kamikawa, Ryoma and Yubuki, Naoji and Yoshida, Masaki and Taira, Misaka and Nakamura, Noriaki and Ishida, Ken-ichiro and Leander, Brian S. and Miyashita, Hideaki and Hashimoto, Tetsuo and Mayama, Shigeki and Inagaki, Yuji} } @article {MartinezMartinez2015, title = {New lipid envelope-containing dsDNA virus isolates infecting Micromonas pusilla reveal a separate phylogenetic group}, journal = {Aquatic Microbial Ecology}, volume = {74}, year = {2015}, note = {tex.mendeley-tags: rcc}, pages = {17{\textendash}28}, abstract = {Viral infection of phytoplankton has major implications for biochemical and energy cycles, community dynamics, and microbial evolution in the marine environment. The non-bloom forming picoplankter Micromonas pusilla, a significant component of the plankton community worldwide, is known to be susceptible to infection by both dsDNA and dsRNA viruses. Logically, comprehensive knowledge of the ecology of M. pusilla requires a better understanding of the div - ersity and infection mechanisms of their viruses. Here, we investigated 19 new M. pusilla-specific viruses (MpVs) isolated from different locations and years. We performed partial characterization of those MpVs including structural characteristics, genome size, phylogenetic analysis based on partial DNA polymerase gene sequences, host range, and stability at different temperatures and upon exposure to chloroform. Combined, these characteristics allowed classification of the MpVs into 2 groups. Exposure to chloroform led to loss of infectivity by all MpVs in one group, which sug- gests the presence of an outer lipid envelope. In addition, all except one of the members in that group formed a monophylogenetic clade that was distinct from all other MpV isolates. The distinc- tive characteristics of the 2 MpV groups suggest different infection strategies, which may have im- portant implications for the ecology of both host and virus populations in the environment. Knowl- edge gained from our study adds value to the MpV isolates as a scientific resource as it will aid in developing and testing in the laboratory new hypotheses about the ecological and biogeochemical implications of M. pusilla viral infection in the environment}, keywords = {characterization, micromonas pusilla, ncldv, phycodnaviridae, rcc, RCC?o?dd, virus diversity}, issn = {0948-3055}, doi = {10.3354/ame01723}, url = {http://www.int-res.com/abstracts/ame/v74/n1/p17-28/}, author = {Mart{\'\i}nez Mart{\'\i}nez, J and Boere, A and Gilg, I and van Lent, Jwm and Witte, Hj and van Bleijswijk, Jdl and Brussaard, Cpd} } @article {Stuken2015, title = {Paralytic shellfish toxin content is related to genomic sxtA4 copy number in Alexandrium minutum strains}, journal = {Frontiers in Microbiology}, volume = {6}, number = {May}, year = {2015}, note = {tex.mendeley-tags: 2015,rcc,sbr?hyto$_\textrmd$ipo}, pages = {1{\textendash}10}, abstract = {Dinoflagellates are microscopic aquatic eukaryotes with huge genomes and an unusual cell regulation. For example, most genes are present in numerous copies and all copies seem to be obligatorily transcribed. The consequence of the gene copy number (CPN) for final protein synthesis is, however, not clear. One such gene is sxtA, the starting gene of paralytic shellfish toxin (PST) synthesis. PSTs are small neurotoxic compounds that can accumulate in the food chain and cause serious poisoning incidences when ingested. They are produced by dinoflagellates of the genera Alexandrium, Gymnodium, and Pyrodinium. Here we investigated if the genomic CPN of sxtA4 is related to PST content in Alexandrium minutum cells. SxtA4 is the 4th domain of the sxtA gene and its presence is essential for PST synthesis in dinoflagellates. We used PST and genome size measurements as well as quantitative PCR to analyze sxtA4 CPN and toxin content in 15 A. minutum strains. Our results show a strong positive correlation between the sxtA4 CPN and the total amount of PST produced in actively growing A. minutum cells. This correlation was independent of the toxin profile produced, as long as the strain contained the genomic domains sxtA1 and sxtA4.}, keywords = {2015, Alexandrium, copy, copy number variation, Dinoflagellate, gene dosage, genome size, number variation, paralytic shellfish toxin, paralytic shellfish toxin (PST), pst, rcc, RCC?o?dd, saxitoxin, saxitoxin (STX), sbr?hyto$_\textrmd$ipo, stx, sxtA}, issn = {1664-302X}, doi = {10.3389/fmicb.2015.00404}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2015.00404}, author = {St{\"u}ken, Anke and Riob{\'o}, Pilar and Franco, Jos{\'e} and Jakobsen, Kjetill S. and Guillou, Laure and Figueroa, Rosa I.} } @article {Andersen2015, title = {Phaeocystis rex sp. nov. (Phaeocystales, Prymnesiophyceae): a new solitary species that produces a multilayered scale cell covering}, journal = {European Journal of Phycology}, volume = {50}, number = {2}, year = {2015}, note = {Publisher: Taylor \& Francis tex.mendeley-tags: 2015,RCC 4025,rcc}, pages = {207{\textendash}222}, abstract = {A morphologically distinct marine species, Phaeocystis rex sp. nov., was described on the basis of light microscopy, transmission electron microscopy and DNA sequence comparisons. Non-motile cells were solitary (non-colonial), 6{\textendash}10 {\textmu}m in diameter and 8{\textendash}15 {\textmu}m long, and possessed chloroplasts with distinctive finger-like lobes. TEM observations demonstrated the presence of two short flagella and a very short haptonema that arose from an invagination of the protoplast. Non-motile cells were surrounded by one to several dense layers composed of scales, presumably unmineralized, and an amorphous material. Phylogenetic analyses based upon combined partial nucleotide sequences for five nuclear-or plastid-encoded genes (18S rRNA, 28S rRNA, 16S rRNA, psbA and rbcL) from cultured strains and from uncharacterized acantharian symbionts confirmed that P. rex was a distinct species. These analyses implied that P. rex occupies an intermediate evolutionary position between solitary and colonial Phaeocystis species.}, keywords = {2015, algae, organic scales, Phaeocystales, Phaeocystis rex, Prymnesiophyceae, rcc, RCC4025, RCC?o?dd, SBR$_\textrmP$hyto$_\textrmE$PPO, systematics, ultrastructure}, issn = {0967-0262}, doi = {10.1080/09670262.2015.1024287}, url = {http://www.tandfonline.com/doi/full/10.1080/09670262.2015.1024287}, author = {Andersen, Robert A. and Bailey, J. Craig and Decelle, Johan and Probert, Ian} } @article {Gerecht2015, title = {Phosphorus availability modifies carbon production in Coccolithus pelagicus (Haptophyta)}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {472}, year = {2015}, note = {tex.mendeley-tags: RCC1200}, month = {nov}, pages = {24{\textendash}31}, abstract = {The coccolithophore Coccolithus pelagicus (Wallich) Schiller fixes CO{\textexclamdown}inf{\textquestiondown}2{\textexclamdown}/inf{\textquestiondown} into particulate organic carbon (POC) through photosynthesis and into particulate inorganic carbon (PIC) in the form of calcite. To examine the role of phosphorus (P) availability in the production of POC and PIC, C. pelagicus subsp. braarudii (Gaarder) Geisen et al. was grown in semi-continuous cultures at three initial phosphate concentrations (P-replete, 1, and 0.5??M [P]). Reduced P-availability (1 and 0.5??M [P]) decreased POC production, while PIC production only decreased when phosphate concentrations became growth limiting (0.5??M [P]). This decrease has not been observed previously in batch cultures, highlighting the inadequacy of the batch culture approach with regard to determining carbon production. The reduction in growth rate by 50\% at 0.5??M [P] was accompanied by a doubling in cell volume (and POC). PIC production was halved, resulting in a lowered PIC to POC ratio. The average number of coccoliths per cell (and PIC content) remained the same among treatments, despite the significant change in cell size. Our data suggest that POC production in C. pelagicus is more sensitive towards a moderate reduction in phosphorus availability than PIC production. Once phosphorus availability limits cell division, however, phosphorus resources are invested into POC rather than PIC production. This reduces cell density and sinking rates, indicating that coccoliths do not act as ballast for reaching deeper nutrient-rich layers under nutrient limitation.}, keywords = {Calcification, Carbon production, Coccolithus pelagicus, Phosphorus limitation, RCC1200, Semi-continuous culture}, issn = {00220981}, doi = {10.1016/j.jembe.2015.06.019}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0022098115001756}, author = {Gerecht, A.C. and {\v S}upraha, L. and Edvardsen, B. and Langer, G. and Henderiks, J.} } @article {Decelle2015, title = {PhytoREF: a reference database of the plastidial 16S rRNA gene of photosynthetic eukaryotes with curated taxonomy}, journal = {Molecular Ecology Resources}, volume = {15}, number = {6}, year = {2015}, note = {tex.mendeley-tags: 2015,macumba,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?ppo}, pages = {1435{\textendash}1445}, abstract = {Photosynthetic eukaryotes have a critical role as the main producers in most ecosystems of the biosphere. The ongo- ing environmental metabarcoding revolution opens the perspective for holistic ecosystems biological studies of these organisms, in particular the unicellular microalgae that often lack distinctive morphological characters and have complex life cycles. To interpret environmental sequences, metabarcoding necessarily relies on taxonomically curated databases containing reference sequences of the targeted gene (or barcode) from identified organisms. To date, no such reference framework exists for photosynthetic eukaryotes. In this study, we built the PhytoREF data- base that contains 6490 plastidial 16S rDNA reference sequences that originate from a large diversity of eukaryotes representing all known major photosynthetic lineages. We compiled 3333 amplicon sequences available from public databases and 879 sequences extracted from plastidial genomes, and generated 411 novel sequences from cultured marine microalgal strains belonging to different eukaryotic lineages. A total of 1867 environmental Sanger 16S rDNA sequences were also included in the database. Stringent quality filtering and a phylogeny-based taxonomic classifica- tion were applied for each 16S rDNA sequence. The database mainly focuses on marine microalgae, but sequences from land plants (representing half of the PhytoREF sequences) and freshwater taxa were also included to broaden the applicability of PhytoREF to different aquatic and terrestrial habitats. PhytoREF, accessible via a web interface (http://phytoref.fr), is a new resource in molecular ecology to foster the discovery, assessment and monitoring of the diversity of photosynthetic eukaryotes using high-throughput sequencing.}, keywords = {2015, MACUMBA, rcc, RCC?o?dd, SBR$_\textrmP$hyto$_\textrmD$IPO, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto$_\textrmd$ipo, sbr?hyto?ppo}, issn = {1755098X}, doi = {10.1111/1755-0998.12401}, url = {http://doi.wiley.com/10.1111/1755-0998.12401}, author = {Decelle, Johan and Romac, Sarah and Stern, Rowena F. and Bendif, El Mahdi and Zingone, Adriana and Audic, St{\'e}phane and Guiry, Michael D. and Guillou, Laure and Tessier, D{\'e}sir{\'e} and Le Gall, Florence and Gourvil, Priscillia and dos Santos, Adriana Lopes and Probert, Ian and Vaulot, Daniel and de Vargas, Colomban and Christen, Richard} } @article {Abby2014, title = {Bacteria in Ostreococcus tauri cultures - friends, foes or hitchhikers?}, journal = {Frontiers in microbiology}, volume = {5}, year = {2014}, note = {Publisher: Frontiers tex.mendeley-tags: rcc}, month = {jan}, pages = {505}, abstract = {Marine phytoplankton produce half of the oxygen we breathe and their astounding diversity is just starting to be unraveled. Many microbial phytoplankton are thought to be phototrophic, depending solely on inorganic sources of carbon and minerals for growth rather than preying on other planktonic cells. However, there is increasing evidence that symbiotic associations, to a large extent with bacteria, are required for vitamin or nutrient uptake for many eukaryotic microalgae. Here, we use in silico approaches to look for putative symbiotic interactions by analysing the gene content of microbial communities associated with 13 different Ostreococcus tauri (Chlorophyta, Mamilleophyceae) cultures sampled from the Mediterranean Sea. While we find evidence for bacteria in all cultures, there is no ubiquitous bacterial group, and the most prevalent group, Flavobacteria, is present in 10 out of 13 cultures. Among seven of the microbiomes, we detected genes predicted to encode type 3 secretion systems (T3SS, in 6/7 microbiomes) and/or putative type 6 secretion systems (T6SS, in 4/7 microbiomes). Phylogenetic analyses show that the corresponding genes are closely related to genes of systems identified in bacterial-plant interactions, suggesting that these T3SS might be involved in cell-to-cell interactions with O. tauri.}, keywords = {bacterial diversity, Bacterial symbiosis, Illumina sequencing, microbiome, Ostreococcus, phycosphere, phytoplankton, picoeukaryote, rcc, RCC?o?dd, secretion system}, issn = {1664-302X}, doi = {10.3389/fmicb.2014.00505}, url = {http://journal.frontiersin.org/Journal/10.3389/fmicb.2014.00505/abstract}, author = {Abby, Sophie S and Touchon, Marie and De Jode, Aurelien and Grimsley, Nigel and Piganeau, Gwenael} } @article {Probert2014a, title = {Brandtodinium gen. nov. and B. nutricula comb. Nov. (Dinophyceae), a dinoflagellate commonly found in symbiosis with polycystine radiolarians}, journal = {Journal of Phycology}, volume = {50}, number = {2}, year = {2014}, note = {tex.mendeley-tags: RCC3378,RCC3379,RCC3380,RCC3381,RCC3382,RCC3383,RCC3384,RCC3385,RCC3386,RCC3387,RCC3388}, pages = {388{\textendash}399}, abstract = {Symbiotic interactions between pelagic hosts and microalgae have received little attention, although they are widespread in the photic layer of the world ocean, where they play a fundamental role in the ecology of the planktonic ecosystem. Polycystine radiolarians (including the orders Spumellaria, Collodaria and Nassellaria) are planktonic heterotrophic protists that are widely distributed and often abundant in the ocean. Many polycystines host symbiotic microalgae within their cytoplasm, mostly thought to be the dinoflagellate Scrippsiella nutricula, a species originally described by Karl Brandt in the late nineteenth century as Zooxanthella nutricula. The free-living stage of this dinoflagellate has never been characterized in terms of morphology and thecal plate tabulation. We examined morphological characters and sequenced conservative ribosomal markers of clonal cultures of the free-living stage of symbiotic dinoflagellates isolated from radiolarian hosts from the three polycystine orders. In addition, we sequenced symbiont genes directly from several polycystine-symbiont holobiont specimens from different oceanic regions. Thecal plate arrangement of the free-living stage does not match that of Scrippsiella or related genera, and LSU and SSU rDNA-based molecular phylogenies place these symbionts in a distinct clade within the Peridiniales. Both phylogenetic analyses and the comparison of morphological features of culture strains with those reported for other closely related species support the erection of a new genus that we name Brandtodinium gen. nov. and the recombination of S. nutricula as B. nutricula comb. nov.}, keywords = {Dinoflagellate, MACUMBA, Peridiniales, polycystines, Radiolaria, rcc, RCC3378, RCC3379, RCC3380, RCC3381, RCC3382, RCC3383, RCC3384, RCC3385, RCC3386, RCC3387, RCC3388, SBR$_\textrmP$hyto$_\textrmD$PO, Scrippsiella, symbiosis, taxonomy, Zooxanthella}, doi = {10.1111/jpy.12174}, url = {http://dx.doi.org/10.1111/jpy.12174}, author = {Probert, Ian and Siano, Raffaele and Poirier, Camille and Decelle, Johan and Biard, Tristan and Tuji, Akihiro and Suzuki, Noritoshi and Not, Fabrice} } @article {Bombar2014, title = {Comparative genomics reveals surprising divergence of two closely related strains of uncultivated UCYN-A cyanobacteria}, journal = {The ISME Journal}, volume = {8}, number = {12}, year = {2014}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: rcc}, pages = {2530{\textendash}2542}, keywords = {rcc}, issn = {1751-7362}, doi = {10.1038/ismej.2014.167}, url = {http://www.nature.com/doifinder/10.1038/ismej.2014.167}, author = {Bombar, Deniz and Heller, Philip and Sanchez-Baracaldo, Patricia and Carter, Brandon J and Zehr, Jonathan P} } @article {Pittera2014, title = {Connecting thermal physiology and latitudinal niche partitioning in marine Synechococcus}, journal = {The ISME journal}, volume = {8}, number = {6}, year = {2014}, note = {Publisher: International Society for Microbial Ecology tex.mendeley-tags: 2014,macumba,microb3,rcc,sbr?hyto?app}, pages = {1221{\textendash}1236}, abstract = {Marine Synechococcus cyanobacteria constitute a monophyletic group that displays a wide latitudinal distribution, ranging from the equator to the polar fronts. Whether these organisms are all physiologically adapted to stand a large temperature gradient or stenotherms with narrow growth temperature ranges has so far remained unexplored. We submitted a panel of six strains, isolated along a gradient of latitude in the North Atlantic Ocean, to long- and short-term variations of temperature. Upon a downward shift of temperature, the strains showed strikingly distinct resistance, seemingly related to their latitude of isolation, with tropical strains collapsing while northern strains were capable of growing. This behaviour was associated to differential photosynthetic performances. In the tropical strains, the rapid photosystem II inactivation and the decrease of the antioxydant [beta]-carotene relative to chl a suggested a strong induction of oxidative stress. These different responses were related to the thermal preferenda of the strains. The northern strains could grow at 10[thinsp][deg]C while the other strains preferred higher temperatures. In addition, we pointed out a correspondence between strain isolation temperature and phylogeny. In particular, clades I and IV laboratory strains were all collected in the coldest waters of the distribution area of marine Synechococus. We, however, show that clade I Synechococcus exhibit different levels of adaptation, which apparently reflect their location on the latitudinal temperature gradient. This study reveals the existence of lineages of marine Synechococcus physiologically specialised in different thermal niches, therefore suggesting the existence of temperature ecotypes within the marine Synechococcus radiation.}, keywords = {2014, adaptation, ecotype, MACUMBA, marine cyanobacteria, MicroB3, rcc, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto?app, Synechococcus, temperature}, doi = {10.1038/ismej.2013.228}, url = {http://dx.doi.org/10.1038/ismej.2013.228 10.1038/ismej.2013.228}, author = {Pittera, Justine and Humily, Florian and Thorel, Maxine and Grulois, Daphne and Garczarek, Laurence and Six, Christophe} } @article {Bellec2014, title = {Cophylogenetic interactions between marine viruses and eukaryotic picophytoplankton}, journal = {BMC Evolutionary Biology}, volume = {14}, number = {1}, year = {2014}, note = {tex.mendeley-tags: RCC1105,RCC1107,RCC1108,RCC1109,RCC114,RCC2482,RCC2483,RCC2484,RCC2485,RCC344,RCC356,RCC373,RCC418,RCC461,RCC464,RCC465,RCC629,RCC658,RCC745,RCC789,RCC834}, pages = {59}, abstract = {BACKGROUND:Numerous studies have investigated cospeciation (or cophylogeny) in various host-symbiont systems, and different patterns were inferred, from strict cospeciation where symbiont phylogeny mirrors host phylogeny, to complete absence of correspondence between trees. The degree of cospeciation is generally linked to the level of host specificity in the symbiont species and the opportunity they have to switch hosts. In this study, we investigated cophylogeny for the first time in a microalgae-virus association in the open sea, where symbionts are believed to be highly host-specific but have wide opportunities to switch hosts. We studied prasinovirus-Mamiellales associations using 51 different viral strains infecting 22 host strains, selected from the characterisation and experimental testing of the specificities of 313 virus strains on 26 host strains.RESULTS:All virus strains were restricted to their host genus, and most were species-specific, but some of them were able to infect different host species within a genus. Phylogenetic trees were reconstructed for viruses and their hosts, and their congruence was assessed based on these trees and the specificity data using different cophylogenetic methods, a topology-based approach, Jane, and a global congruence method, ParaFit. We found significant congruence between virus and host trees, but with a putatively complex evolutionary history.CONCLUSIONS:Mechanisms other than true cospeciation, such as host-switching, might explain a part of the data. It has been observed in a previous study on the same taxa that the genomic divergence between host pairs is larger than between their viruses. It implies that if cospeciation predominates in this algae-virus system, this would support the hypothesis that prasinoviruses evolve more slowly than their microalgal hosts, whereas host switching would imply that these viruses speciated more recently than the divergence of their host genera.}, keywords = {rcc, RCC1105, rcc1107, RCC1108, RCC1109, RCC114, RCC2482, RCC2483, RCC2484, RCC2485, RCC344, RCC356, RCC373, RCC418, RCC461, RCC464, RCC465, RCC629, RCC658, RCC745, RCC789, RCC834, SBR$_\textrmP$hyto$_\textrmD$PO}, doi = {10.1186/1471-2148-14-59}, url = {http://www.biomedcentral.com/1471-2148/14/59}, author = {Bellec, Laure and Clerissi, Camille and Edern, Roseline and Foulon, Elodie and Simon, Nathalie and Grimsley, Nigel and Desdevises, Yves} } @article {Lepelletier2014a, title = {Dinomyces arenysensis gen. et sp. nov. (rhizophydiales, dinomycetaceae fam. nov.), a chytrid infecting marine dinoflagellates}, journal = {Protist}, volume = {165}, number = {2}, year = {2014}, note = {tex.mendeley-tags: 2014,macumba,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, pages = {230{\textendash}244}, abstract = {Environmental 18S rRNA gene surveys of microbial eukaryotes have recently revealed the diversity of major parasitic agents in pelagic freshwater systems, consisting primarily of chytrid fungi. To date, only a few studies have reported the presence of chydrids in the marine environment and a limited number of marine chytrids have been properly identified and characterized. Here, we report the isolation and cultivation of a marine chytrid from samples taken during a bloom of the toxic dinoflagellate Alexandrium minutum in the Arenys de Mar harbour (Mediterranean Sea, Spain). Cross-infections using cultures and natural phytoplankton communities revealed that this chytrid is only able to infect certain species of dinoflagellates, with a rather wide host range but with a relative preference for Alexandrium species. Phylogenetic analyses showed that it belongs to the order Rhizophydiales, but cannot be included in any of the existing families within this order. Several ultrastructural characters confirmed the placement of this taxon within the Rhizophydiales as well its novelty notably in terms of zoospore structure. This marine chytridial parasitoid is described as a new genus and species, Dinomyces arenysensis, within the Dinomycetaceae fam. nov.}, keywords = {2014, chytrid, Dinoflagellates, Dinomyces arenysensis, Fungi, MACUMBA, microbial parasitoids, rcc, RCC?o?dd, Rhizophydiales., SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, doi = {10.1016/j.protis.2014.02.004}, url = {http://www.sciencedirect.com/science/article/pii/S1434461014000170}, author = {Lepelletier, Fr{\'e}d{\'e}ric and Karpov, Sergey A and Alacid, Elisabet and Le Panse, Sophie and Bigeard, Estelle and Garc{\'e}s, Esther and Jeanthon, Christian and Guillou, Laure} } @article {Chambouvet2014, title = {Diverse molecular signatures for ribosomally {\textquoteright}active{\textquoteright} Perkinsea in marine sediments}, journal = {BMC Microbiology}, volume = {14}, number = {1}, year = {2014}, note = {tex.mendeley-tags: 2014,rcc,sbr?hyto?ppo}, pages = {110}, abstract = {BACKGROUND:Perkinsea are a parasitic lineage within the eukaryotic superphylum Alveolata. Recent studies making use of environmental small sub-unit ribosomal RNA gene (SSU rDNA) sequencing methodologies have detected a significant diversity and abundance of Perkinsea-like phylotypes in freshwater environments. In contrast only a few Perkinsea environmental sequences have been retrieved from marine samples. Only two groups of Perkinsea have been cultured and morphologically described and these are parasites of marine molluscs or marine protists. These two marine groups form separate and distantly related phylogenetic clusters, composed of closely related lineages on SSU rDNA trees. Here, we test the hypothesis that Perkinsea are a hitherto under-sampled group in marine environments. Using 454 diversity {\textquoteright}tag{\textquoteright} sequencing we investigate the diversity and distribution of these protists in marine sediments and water column samples taken from the Deep Chlorophyll Maximum (DCM) and sub-surface using both DNA and RNA as the source template and sampling four European offshore locations.RESULTS:We detected the presence of 265 sequences branching with known Perkinsea, the majority of them recovered from marine sediments. Moreover, 27\% of these sequences were sampled from RNA derived cDNA libraries. Phylogenetic analyses classify a large proportion of these sequences into 38 cluster groups (including 30 novel marine cluster groups), which share less than 97\% sequence similarity as to suggest this diversity encompasses a range of biologically and ecologically distinct organisms.CONCLUSIONS:These results demonstrate that the Perkinsea lineage is considerably more diverse than previously detected in marine environments. This wide diversity of Perkinsea-like protists is largely retrieved in marine sediment with a significant proportion detected in RNA derived libraries suggesting this diversity represents ribosomally {\textquoteright}active{\textquoteright} and intact cells. Given the phylogenetic range of hosts infected by known Perkinsea parasites, these data suggest that Perkinsea either play a significant but hitherto unrecognized role as parasites in marine sediments and/or members of this group are present in the marine sediment possibly as part of the {\textquoteright}seed bank{\textquoteright} microbial community.}, keywords = {2014, Biomarks, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1186/1471-2180-14-110}, url = {http://www.biomedcentral.com/1471-2180/14/110}, author = {Chambouvet, Aurelie and Berney, Cedric and Romac, Sarah and Audic, St{\'e}phane and Maguire, Finlay and de Vargas, Colomban and Richards, Thomas} } @article {hamilton_exposure_2014, title = {Exposure to bloom-like concentrations of two marine Synechococcus cyanobacteria (strains CC9311 and CC9902) differentially alters fish behaviour}, journal = {Conservation Physiology}, volume = {2}, number = {cou020}, year = {2014}, abstract = {Coastal California experiences large-scale blooms of Synechococcus cyanobacteria, which are predicted to become more prevalent by the end of the 21st century as a result of global climate change. This study investigated whether exposure to bloom-like concentrations of two Synechococcus strains, CC9311 and CC9902, alters fish behaviour. Black perch (Embiotoca jacksoni) were exposed to Synechococcus strain CC9311 or CC9902 (1.5 {\texttimes} 106 cells ml-1) or to control seawater in experimental aquaria for 3 days. Fish movement inside a testing arena was then recorded and analysed using video camera-based motion-tracking software. Compared with control fish, fish exposed to CC9311 demonstrated a significant preference for the dark zone of the tank in the light{\textendash}dark test, which is an indication of increased anxiety. Furthermore, fish exposed to CC9311 also had a statistically significant decrease in velocity and increase in immobility and they meandered more in comparison to control fish. There was a similar trend in velocity, immobility and meandering in fish exposed to CC9902, but there were no significant differences in behaviour or locomotion between this group and control fish. Identical results were obtained with a second batch of fish. Additionally, in this second trial we also investigated whether fish would recover after a 3 day period in seawater without cyanobacteria. Indeed, there were no longer any significant differences in behaviour among treatments, demonstrating that the sp. CC9311-induced alteration of behaviour is reversible. These results demonstrate that blooms of specific marine Synechococcus strains can induce differential sublethal effects in fish, namely alterations light{\textendash}dark preference behaviour and motility.}, keywords = {RCC1086}, issn = {2051-1434}, doi = {10.1093/conphys/cou020}, url = {https://doi.org/10.1093/conphys/cou020}, author = {Hamilton, T. J. and Paz-Yepes, J. and Morrison, R. A. and Palenik, B. and Tresguerres, M.} } @article {Bendif2014, title = {Genetic delineation between and within the widespread coccolithophore morpho-species Emiliania huxleyi and Gephyrocapsa oceanica (Haptophyta)}, journal = {Journal of Phycology}, volume = {50}, year = {2014}, note = {tex.mendeley-tags: 2014,cc3549,rcc,rcc1210,rcc1213,rcc1220,rcc1227,rcc1229,rcc1242,rcc1252,rcc1253,rcc1258,rcc1259,rcc1260,rcc1271,rcc1281,rcc1288,rcc1292,rcc1297,rcc1300,rcc1303,rcc1305,rcc1316,rcc1562,rcc174,rcc1839,rcc3545,rrcc1247,sbr?hyto?ppo}, pages = {140{\textendash}148}, keywords = {2014, cc3549, rcc, rcc1210, RCC1213, rcc1220, rcc1227, rcc1229, RCC1242, rcc1252, RCC1253, rcc1258, RCC1259, rcc1260, rcc1271, RCC1281, rcc1288, RCC1292, rcc1297, RCC1300, RCC1303, RCC1305, RCC1316, RCC1562, rcc174, RCC1839, rcc3545, rrcc1247, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1111/jpy.12147}, author = {Bendif, El Mahdi and Probert, Ian and Carmichael, Margaux and Romac, Sarah and Hagino, Kyoko and de Vargas, Colomban} } @article {Nezan2014, title = {Genetic diversity of the harmful family Kareniaceae (Gymnodiniales, Dinophyceae) in France, with the description of {\textexclamdown}i{\textquestiondown}Karlodinium gentienii{\textexclamdown}/i{\textquestiondown} sp. nov.: A new potentially toxic dinoflagellate}, journal = {Harmful Algae}, volume = {40}, year = {2014}, note = {tex.mendeley-tags: 2014,rcc,sbr?hyto?app}, pages = {75{\textendash}91}, abstract = {A B S T R A C T The family Kareniaceae is mostly known in France for recurrent blooms of Karenia mikimotoi in the Atlantic, English Channel, and Mediterranean Sea and for the unusual green discoloration in the saltwater lagoon of Diana (Corsica) caused by Karlodinium corsicum in April 1994. In terms of diversity, this taxonomic group was long overlooked owing to the difficult identification of these small unarmored dinoflagellates. In this study, thanks to the molecular characterization performed on single cells from field samples and cultures, twelve taxonomic units were assigned to the known genera Karenia, Karlodinium and Takayama, whereas one could not be affiliated to any described genus. The molecular phylogeny inferred from the D1{\textendash}D2 region of the LSU rDNA showed that five of them formed a sister taxon of a known species, and could not be identified at species-level, on the basis of molecular analysis only. Among these latter taxa, one Karlodinium which was successfully cultured was investigated by studying the external morphological features (using two procedures for cells fixation), ultrastructure, pigment composition, and haemolytic activity. The results of our analyses corroborate the genetic results in favour of the erection of Karlodinium gentienii sp. nov., which possesses an internal complex system of trichocysts connected to external micro-processes particularly abundant in the epicone, and a peculiar pigment composition. In addition, preliminary assays showed a haemolytic activity.}, keywords = {2014, rcc, sbr?hyto?app}, issn = {15689883}, doi = {10.1016/j.hal.2014.10.006}, url = {http://linkinghub.elsevier.com/retrieve/pii/S1568988314001863}, author = {N{\'e}zan, Elisabeth and Siano, Raffaele and Boulben, Sylviane and Six, Christophe and Bilien, Gwenael and Ch{\`e}ze, Karine and Duval, Audrey and Le Panse, Sophie and Qu{\'e}r{\'e}, Julien and Chom{\'e}rat, Nicolas} } @article {Biller2014, title = {Genomes of diverse isolates of the marine cyanobacterium Prochlorococcus}, journal = {Scientific Data}, volume = {1}, year = {2014}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: rcc}, month = {sep}, pages = {1{\textendash}11}, abstract = {The marine cyanobacterium Prochlorococcus is the numerically dominant photosynthetic organism in the oligotrophic oceans, and a model system in marine microbial ecology. Here we report 27 new whole genome sequences (2 complete and closed; 25 of draft quality) of cultured isolates, representing five major phylogenetic clades of Prochlorococcus. The sequenced strains were isolated from diverse regions of the oceans, facilitating studies of the drivers of microbial diversity{\textemdash}both in the lab and in the field. To improve the utility of these genomes for comparative genomics, we also define pre-computed clusters of orthologous groups of proteins (COGs), indicating how genes are distributed among these and other publicly available Prochlorococcus genomes. These data represent a significant expansion of Prochlorococcus reference genomes that are useful for numerous applications in microbial ecology, evolution and oceanography.}, keywords = {Environmental microbiology, genomics, rcc, RCC?o?dd}, issn = {2052-4463}, doi = {10.1038/sdata.2014.34}, url = {http://www.nature.com/articles/sdata201434}, author = {Biller, Steven J. and Berube, Paul M. and Berta-Thompson, Jessie W. and Kelly, Libusha and Roggensack, Sara E. and Awad, Lana and Roache-Johnson, Kathryn H. and Ding, Huiming and Giovannoni, Stephen J. and Rocap, Gabrielle and Moore, Lisa R. and Chisholm, Sallie W. and H. and Ding, Huiming and Giovannoni, Stephen J. and Moore, Lisa R. and Chisholm, Sallie W.} } @article {Marie2014, title = {An improved protocol for flow cytometry analysis of phytoplankton cultures and natural samples}, journal = {Cytometry}, volume = {85}, year = {2014}, note = {tex.mendeley-tags: RCC100,RCC1085,RCC114,RCC156,RCC168,RCC174,RCC180,RCC190,RCC263,RCC365,RCC400,RCC432,RCC446,RCC475,RCC480,RCC504,RCC745,RCC91}, pages = {962{\textendash}968}, abstract = {Preservation of cells, choice of fixative, storage, and thawing conditions are recurrent issues for the analysis of phytoplankton by flow cytometry. We examined the effects of addition of the surfactant Pluronic F68 to glutaraldehyde-fixed photosynthetic organisms in cultures and natural samples. In particular, we examined cell losses and modifications of side scatter (a proxy of cell size) and fluorescence of natural pigments. We found that different marine phytoplankton species react differently to the action of Pluronic F68. In particular, photosynthetic prokaryotes are less sensitive than eukaryotes. Observed cell losses may result from cell lysis or from cell adhesion to the walls of plastic tubes that are commonly used for flow cytometry analysis. The addition of the surfactant, Pluronic F68, has a positive effect on cells for long-term storage. We recommend to modify current protocols for preservation of natural marine planktonic samples, by fixing them with glutaraldehyde 0.25\% (final concentration) and adding Pluronic F68 at a final concentration of 0.01\% in the samples before preservation. Pluronic F68 also appears effective for preserving samples without fixation for subsequent sorting, e.g. for molecular biology analyses. (c) 2014 International Society for Advancement of Cytometry}, keywords = {ASSEMBLE, MACUMBA, RCC100, RCC1085, RCC114, RCC156, RCC168, rcc174, RCC180, RCC190, RCC263, RCC365, RCC400, RCC432, RCC446, RCC475, RCC480, RCC504, RCC745, RCC91, RCC?o?dd, SBR$_\textrmP$hyto$_\textrmD$PO}, doi = {10.1002/cyto.a.22517}, author = {Marie, D and Rigaut-Jalabert, F and Vaulot, D} } @article {Duanmu2014, title = {Marine algae and land plants share conserved phytochrome signaling systems}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {44}, year = {2014}, note = {tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {15827{\textendash}15832}, abstract = {Phytochrome photosensors control a vast gene network in streptophyte plants, acting as master regulators of diverse growth and developmental processes throughout the life cycle. In contrast with their absence in known chlorophyte algal genomes and most sequenced prasinophyte algal genomes, a phytochrome is found in Micromonas pusilla, a widely distributed marine picoprasinophyte ({\textexclamdown}2 {\textmu}m cell diameter). Together with phytochromes identified from other prasinophyte lineages, we establish that prasinophyte and streptophyte phytochromes share core light-input and signaling-output domain architectures except for the loss of C-terminal response regulator receiver domains in the streptophyte phytochrome lineage. Phylogenetic reconstructions robustly support the presence of phytochrome in the common progenitor of green algae and land plants. These analyses reveal a monophyletic clade containing streptophyte, prasinophyte, cryptophyte, and glaucophyte phytochromes implying an origin in the eukaryotic ancestor of the Archaeplastida. Transcriptomic measurements reveal diurnal regulation of phytochrome and bilin chromophore biosynthetic genes in Micromonas. Expression of these genes precedes both light-mediated phytochrome redistribution from the cytoplasm to the nucleus and increased expression of photosynthesis-associated genes. Prasinophyte phytochromes perceive wavelengths of light transmitted farther through seawater than the red/far-red light sensed by land plant phytochromes. Prasinophyte phytochromes also retain light-regulated histidine kinase activity lost in the streptophyte phytochrome lineage. Our studies demonstrate that light-mediated nuclear translocation of phytochrome predates the emergence of land plants and likely represents a widespread signaling mechanism in unicellular algae.}, keywords = {Micromonas, rcc}, doi = {10.1073/pnas.1416751111}, url = {http://www.pnas.org/content/111/44/15827.abstract}, author = {Duanmu, Deqiang and Bachy, Charles and Sudek, Sebastian and Wong, Chee-Hong and Jimenez, Valeria and Rockwell, Nathan C and Martin, Shelley S and Ngan, Chew Yee and Reistetter, Emily N and van Baren, Marijke J and Price, Dana C and Wei, Chia-Lin and Reyes-Prieto, Adrian and Lagarias, J Clark and Worden, Alexandra Z} } @article {Keeling2014, title = {The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing}, journal = {PLoS biology}, volume = {12}, number = {6}, year = {2014}, note = {Publisher: Public Library of Science tex.mendeley-tags: 2014,rcc,sbr?hyto$_\textrmd$ipo}, pages = {e1001889}, abstract = {Current sampling of genomic sequence data from eukaryotes is relatively poor, biased, and inadequate to address important questions about their biology, evolution, and ecology; this Community Page describes a resource of 700 transcriptomes from marine microbial eukaryotes to help understand their role in the world{\textquoteright}s oceans}, keywords = {2014, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.1371/journal.pbio.1001889}, url = {http://dx.doi.org/10.1371\%252Fjournal.pbio.1001889}, author = {Keeling, Patrick J and Burki, Fabien and Wilcox, Heather M and Allam, Bassem and Allen, Eric E and Amaral-Zettler, Linda A and Armbrust, E Virginia and Archibald, John M and Bharti, Arvind K and Bell, Callum J and Beszteri, Bank and Bidle, Kay D and Cameron, Connor T and Campbell, Lisa and Caron, David A and Cattolico, Rose Ann and Collier, Jackie L and Coyne, Kathryn and Davy, Simon K and Deschamps, Phillipe and Dyhrman, Sonya T and Edvardsen, Bente and Gates, Ruth D and Gobler, Christopher J and Greenwood, Spencer J and Guida, Stephanie M and Jacobi, Jennifer L and Jakobsen, Kjetill S and James, Erick R and Jenkins, Bethany and John, Uwe and Johnson, Matthew D and Juhl, Andrew R and Kamp, Anja and Katz, Laura A and Kiene, Ronald and Kudryavtsev, Alexander and Leander, Brian S and Lin, Senjie and Lovejoy, Connie and Lynn, Denis and Marchetti, Adrian and McManus, George and Nedelcu, Aurora M and Menden-Deuer, Susanne and Miceli, Cristina and Mock, Thomas and Montresor, Marina and Moran, Mary Ann and Murray, Shauna and Nadathur, Govind and Nagai, Satoshi and Ngam, Peter B and Palenik, Brian and Pawlowski, Jan and Petroni, Giulio and Piganeau, Gwenael and Posewitz, Matthew C and Rengefors, Karin and Romano, Giovanna and Rumpho, Mary E and Rynearson, Tatiana and Schilling, Kelly B and Schroeder, Declan C and Simpson, Alastair G B and Slamovits, Claudio H and Smith, David R and Smith, G Jason and Smith, Sarah R and Sosik, Heidi M and Stief, Peter and Theriot, Edward and Twary, Scott N and Umale, Pooja E and Vaulot, Daniel and Wawrik, Boris and Wheeler, Glen L and Wilson, William H and Xu, Yan and Zingone, Adriana and Worden, Alexandra Z} } @article {Morrissey2014, title = {A novel protein, ubiquitous in marine phytoplankton, concentrates iron at the cell surface and facilitates uptake}, journal = {Current Biology}, volume = {25}, number = {3}, year = {2014}, note = {tex.mendeley-tags: rcc}, month = {dec}, pages = {364{\textendash}371}, abstract = {Numerous cellular functions including respiration require iron. Plants and phytoplankton must also maintain the iron-rich photosynthetic electron transport chain, which most likely evolved in the iron-replete reducing environments of the Proterozoic ocean [1]. Iron bioavailability has drastically decreased in the contemporary ocean [1], most likely selecting for the evolution of efficient iron acquisition mechanisms among modern phytoplankton. Mesoscale iron fertilization experiments often result in blooms dominated by diatoms [2], indicating that diatoms have adaptations that allow survival in iron-limited waters and rapid multiplication when iron becomes available. Yet the genetic and molecular bases are unclear, as very few iron uptake genes have been functionally characterized from marine eukaryotic phytoplankton, and large portions of diatom iron starvation transcriptomes are genes encoding unknown functions [3{\textendash}5]. Here we show that the marine diatom Phaeodactylum tricornutum utilizes ISIP2a to concentrate Fe(III) at the cell surface as part of a novel, copper-independent and thermodynamically controlled iron uptake system. ISIP2a is expressed in response to iron limitation several days prior to the induction of ferrireductase activity, and it facilitates significant Fe(III) uptake during the initial response to Fe limitation. ISIP2a is able to directly bind Fe(III) and increase iron uptake when heterologously expressed, whereas knockdown of ISIP2a in P. tricornutum decreases iron uptake, resulting in impaired growth and chlorosis during iron limitation. ISIP2a is expressed by diverse marine phytoplankton, indicating that it is an ecologically significant adaptation to the unique nutrient composition of marine environments.}, keywords = {rcc}, issn = {09609822}, doi = {10.1016/j.cub.2014.12.004}, url = {http://www.sciencedirect.com/science/article/pii/S0960982214015632}, author = {Morrissey, Joe and Sutak, Robert and Paz-Yepes, Javier and Tanaka, Atsuko and Moustafa, Ahmed and Veluchamy, Alaguraj and Thomas, Yann and Botebol, Hugo and Bouget, Fran{\c c}ois-Yves and McQuaid, Jeffrey B. and Tirichine, Leila and Allen, Andrew E. and Lesuisse, Emmanuel and Bowler, Chris} } @article {DelCampo2014, title = {The others: our biased perspective of eukaryotic genomes}, journal = {Trends in Ecology \& Evolution}, volume = {29}, number = {5}, year = {2014}, note = {Publisher: Elsevier tex.mendeley-tags: RCC,rcc}, pages = {252{\textendash}259}, abstract = {?There is an important bias in eukaryotic knowledge, affecting cultures and genomes.?Eukaryotic genomics are biased towards multicellular organisms and their parasites.?A phylogeny-driven initiative is needed to overcome the eukaryotic genomic bias.?We propose to sequence neglected cultures and increase culturing efforts.?Single-cell genomics should be embraced as a tool to explore eukaryotic diversity.}, keywords = {rcc}, doi = {10.1016/j.tree.2014.03.006}, url = {http://www.cell.com/trends/ecology-evolution/abstract/S0169-5347(14)00064-0}, author = {del Campo, Javier and Sieracki, Michael E and Molestina, Robert and Keeling, Patrick and Massana, Ramon and Ruiz-Trillo, I{\~n}aki} } @article {Lepelletier2014, title = {Parvilucifera rostrata sp. nov., a novel parasite in the phylum Perkinsozoa that infects the toxic dinoflagellate Alexandrium minutum (Dinophyceae)}, journal = {Protist}, volume = {165}, year = {2014}, note = {tex.mendeley-tags: 2014,macumba,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, pages = {31{\textendash}49}, keywords = {2014, MACUMBA, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, doi = {10.1016/j.protis.2013.09.005}, author = {Lepelletier, F and Karpov, S A and Le Panse, S and Bigeard, E and Skovgaard, A and Jeanthon, C and Guillou, L} } @article {Kashtan2014, title = {Single-cell genomics reveals hundreds of coexisting subpopulations in wild prochlorococcus}, journal = {Science}, volume = {344}, number = {6182}, year = {2014}, note = {tex.mendeley-tags: RCC278}, pages = {416{\textendash}420}, abstract = {Extensive genomic diversity within coexisting members of a microbial species has been revealed through selected cultured isolates and metagenomic assemblies. Yet, the cell-by-cell genomic composition of wild uncultured populations of co-occurring cells is largely unknown. In this work, we applied large-scale single-cell genomics to study populations of the globally abundant marine cyanobacterium Prochlorococcus. We show that they are composed of hundreds of subpopulations with distinct {\textquotedblleft}genomic backbones,{\textquotedblright} each backbone consisting of a different set of core gene alleles linked to a small distinctive set of flexible genes. These subpopulations are estimated to have diverged at least a few million years ago, suggesting ancient, stable niche partitioning. Such a large set of coexisting subpopulations may be a general feature of free-living bacterial species with huge populations in highly mixed habitats.}, keywords = {RCC278}, doi = {10.1126/science.1248575}, url = {http://www.sciencemag.org/content/344/6182/416.abstract}, author = {Kashtan, Nadav and Roggensack, Sara E and Rodrigue, S{\'e}bastien and Thompson, Jessie W and Biller, Steven J and Coe, Allison and Ding, Huiming and Marttinen, Pekka and Malmstrom, Rex R and Stocker, Roman and Follows, Michael J and Stepanauskas, Ramunas and Chisholm, Sallie W} } @article {Dia2014, title = {Spatiotemporal changes in the genetic diversity of harmful algal blooms caused by the toxic dinoflagellate Alexandrium minutum}, journal = {Molecular Ecology}, volume = {23}, number = {3}, year = {2014}, note = {tex.mendeley-tags: 2014,macumba,rcc,sbr?hyto$_\textrmd$ipo}, pages = {549{\textendash}560}, abstract = {Organisms with sexual and asexual reproductive systems benefit from both types of reproduction. Sexual recombination generates new combinations of alleles, whereas clonality favours the spread of the fittest genotype through the entire population. Therefore, the rate of sexual vs. clonal reproduction has a major influence on the demography and genetic structure of natural populations. We addressed the effect of reproductive system on populations of the dinoflagellate Alexandrium minutum. More specifically, we monitored the spatiotemporal genetic diversity during and between bloom events in two estuaries separated by 150 km for two consecutive years. An analysis of population genetic patterns using microsatellite markers revealed surprisingly high genotypic and genetic diversity. Moreover, there was significant spatial and temporal genetic differentiation during and between bloom events. Our results demonstrate that (i) interannual genetic differentiation can be very high, (ii) estuaries are partially isolated during bloom events and (iii) genetic diversity can change rapidly during a bloom event. This rapid genetic change may reflect selective effects that are nevertheless not strong enough to reduce allelic diversity. Thus, sexual reproduction and/or migration may regularly erase any genetic structure produced within estuaries during a bloom event.}, keywords = {2014, bloom dynamics, clonality, linkage disequilibrium, MACUMBA, population genetics, rcc, RCC?o?dd, resting cyst, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, sexual reproduction}, doi = {10.1111/mec.12617}, url = {http://dx.doi.org/10.1111/mec.12617}, author = {Dia, A and Guillou, L and Mauger, S and Bigeard, E and Marie, D and Valero, M and Destombe, C} } @article {Kessenich2014, title = {Transcriptomic insights into the life history of bolidophytes , the sister lineage to diatoms}, journal = {Journal of Phycology}, volume = {983}, year = {2014}, note = {tex.mendeley-tags: RCC205}, pages = {977{\textendash}983}, abstract = {Diatoms are perhaps the most diverse lineage of eukaryotic algae, with their siliceous cell wall and diplontic life history often considered to have played important roles in their extraordinary diversification. The characteristic diminution of the diatom cell wall over the course of vegetative growth provides a reliable, intrinsic trigger for sexual reproduction, establishing a direct link between the evolution of their cell-wall and life- history features. It is unclear, however, whether the diplontic life cycle of diatoms represents an ancestral or derived trait. This uncertainty is based in part on our lack of understanding of the life cycle of the sister lineage to diatoms, which includes a mix of two free-living and separately classified forms: naked biflagellate unicells in the genus Bolidomonas and silicified forms in the order Parmales. These two forms might represent different life-history stages, although directly establishing such links can be difficult. We sequenced transcriptomes for Bolidomonas and two diatoms and found that \~0.1\% of the coding regions in the two diploid diatoms are heterozygous, whereas Bolidomonas is virtually devoid of heterozygous alleles, consistent with expectations for a haploid genome. These results suggest that Bolidomonas is haploid and predict that parmaleans represent the diploid phase of a haplodiplontic life cycle. These data fill an important gap in our understanding of the origin of the diplontic life history of diatoms, which may represent an evolutionarily derived, adaptive feature.}, keywords = {Bolidomonas, CCMP1866, diatoms, diplontic, haplodiplontic, life cycle, Parmales, RCC205, RCC?o?dd, Transcriptome}, doi = {10.1111/jpy.12222}, url = {http://dx.doi.org/10.1111/jpy.12222}, author = {Kessenich, Colton R and Ruck, Elizabeth C and Schurko, Andrew M and Wickett, Norman J and Alverson, Andrew J} } @article {Clerissi2014, title = {Unveiling of the diversity of prasinoviruses (phycodnaviridae) in marine samples by using high-throughput sequencing analyses of PCR-Amplified DNA polymerase and major capsid protein genes}, journal = {Applied and Environmental Microbiology}, volume = {80}, number = {10}, year = {2014}, note = {tex.mendeley-tags: Micromonas,rcc}, pages = {3150{\textendash}3160}, abstract = {Viruses strongly influence the ecology and evolution of their eukaryotic hosts in the marine environment, but little is known about their diversity and distribution. Prasinoviruses infect an abundant and widespread class of phytoplankton, the Mamiellophyceae, and thereby exert a specific and important role in microbial ecosystems. However, molecular tools to specifically identify this viral genus in environmental samples are still lacking. We developed two primer sets, designed for use with polymerase chain reactions and 454 pyrosequencing technologies, to target two conserved genes, encoding the DNA polymerase (PolB gene) and the major capsid protein (MCP gene). While only one copy of the PolB gene is present in Prasinovirus genomes, there are at least seven paralogs for MCP, the copy we named number 6 being shared with other eukaryotic alga-infecting viruses. Primer sets for PolB and MCP6 were thus designed and tested on 6 samples from the Tara Oceans project. The results suggest that the MCP6 amplicons show greater richness but that PolB gave a wider coverage of Prasinovirus diversity. As a consequence, we recommend use of the PolB primer set, which will certainly reveal exciting new insights about the diversity and distribution of prasinoviruses at the community scale.}, keywords = {Micromonas, rcc, TARA-Oceans}, doi = {10.1128/aem.00123-14}, url = {http://aem.asm.org/content/80/10/3150.abstract}, author = {Clerissi, Camille and Grimsley, Nigel and Ogata, Hiroyuki and Hingamp, Pascal and Poulain, Julie and Desdevises, Yves} } @article {Abida2013, title = {Bioprospecting marine plankton}, journal = {Marine Drugs}, volume = {11}, number = {11}, year = {2013}, note = {tex.mendeley-tags: 2013,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?ppo}, pages = {4594{\textendash}4611}, keywords = {2013, MicroB3, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, sbr?hyto?ppo}, doi = {10.3390/md11114594}, url = {http://www.mdpi.com/1660-3397/11/11/4594}, author = {Abida, Heni and Ruchaud, Sandrine and Rios, Laurent and Humeau, Anne and Probert, Ian and de Vargas, Colomban and Bach, St{\'e}phane and Bowler, Chris} } @article {Rousseau2013, title = {Characterization of {\textexclamdown}i{\textquestiondown}Phaeocystis globosa{\textexclamdown}/i{\textquestiondown} (haptophyceae), the blooming species in the southern north sea}, journal = {Journal of Sea Research}, volume = {76}, year = {2013}, note = {tex.mendeley-tags: 2013,rcc,sbr?hyto$_\textrmd$ipo}, pages = {105{\textendash}113}, keywords = {2013, ASSEMBLE, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, Souchotheque}, doi = {10.1016/j.seares.2012.07.011}, author = {Rousseau, V and Lantoine, F and Rodriguez, F and Le Gall, F and Chr{\'e}tiennot-Dinet, M.-J. and Lancelot, C} } @article {Bendif2013, title = {On the description of Tisochrysis lutea gen . nov . sp . nov . and Isochrysis nuda sp. nov. in the Isochrysidales, and the transfer of Dicrateria to the Prymnesiales (Haptophyta)}, journal = {Journal of Applied Phycology}, volume = {25}, year = {2013}, note = {tex.mendeley-tags: 2013,RCC1195,RCC1207,RCC1281,RCC1286,RCC1344,RCC1346,RCC1347,RCC1348,RCC1349,RCC1350,RCC1353,RCC2477,RCC3681,RCC3684,RCC3686,RCC3687,RCC3690,RCC3691,RCC3692,RCC3693,RCC3694,RCC3695,RCC3696,RCC3699,RCC3701,RCC3707,rcc,sbr?hyto?ppo}, pages = {1763{\textendash}1776}, keywords = {2013, dicrateria, imantonia, isochrysidaceae, isochrysis galbana, phylogeny, rcc, RCC1195, RCC1207, RCC1281, RCC1286, RCC1344, RCC1346, RCC1347, RCC1348, RCC1349, RCC1350, RCC1353, RCC2477, RCC3681, RCC3684, RCC3686, RCC3687, RCC3690, RCC3691, RCC3692, RCC3693, RCC3694, RCC3695, RCC3696, RCC3699, RCC3701, RCC3707, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo, taxonomy, ultrastructure}, doi = {10.1007/s10811-013-0037-0}, author = {Bendif, El Mahdi and Probert, Ian and Schroeder, Declan C and de Vargas, Colomban} } @article {Monier2013, title = {Gene invasion in distant eukaryotic lineages: discovery of mutually exclusive genetic elements reveals marine biodiversity}, journal = {The ISME journal}, volume = {7}, year = {2013}, note = {Publisher: International Society for Microbial Ecology tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {1764{\textendash}1774}, keywords = {horizontal transfer, inteins, invasive elements, metagenomics, Micromonas, polymorphic introns, rcc, viridiplantae}, doi = {10.1038/ismej.2013.70}, url = {http://dx.doi.org/10.1038/ismej.2013.70 10.1038/ismej.2013.70}, author = {Monier, Adam and Sudek, Sebastian and Fast, Naomi M and Worden, Alexandra Z} } @article {Humily2013, title = {A gene island with two possible configurations is involved in chromatic acclimation in marine synechococcus}, journal = {PLoS ONE}, volume = {8}, number = {12}, year = {2013}, note = {Publisher: Public Library of Science tex.mendeley-tags: 2013,macumba,rcc,sbr?hyto?app}, pages = {e84459}, abstract = {{\textexclamdown}p{\textquestiondown}{\textexclamdown}italic{\textquestiondown}Synechococcus{\textexclamdown}/italic{\textquestiondown}, the second most abundant oxygenic phototroph in the marine environment, harbors the largest pigment diversity known within a single genus of cyanobacteria, allowing it to exploit a wide range of light niches. Some strains are capable of Type IV chromatic acclimation (CA4), a process by which cells can match the phycobilin content of their phycobilisomes to the ambient light quality. Here, we performed extensive genomic comparisons to explore the diversity of this process within the marine {\textexclamdown}italic{\textquestiondown}Synechococcus{\textexclamdown}/italic{\textquestiondown} radiation. A specific gene island was identified in all CA4-performing strains, containing two genes ({\textexclamdown}italic{\textquestiondown}fciA{\textexclamdown}/italic{\textquestiondown}/b) coding for possible transcriptional regulators and one gene coding for a phycobilin lyase. However, two distinct configurations of this cluster were observed, depending on the lineage. CA4-A islands contain the {\textexclamdown}italic{\textquestiondown}mpeZ{\textexclamdown}/italic{\textquestiondown} gene, encoding a recently characterized phycoerythrobilin lyase-isomerase, and a third, small, possible regulator called {\textexclamdown}italic{\textquestiondown}fciC{\textexclamdown}/italic{\textquestiondown}. In CA4-B islands, the lyase gene encodes an uncharacterized relative of MpeZ, called MpeW. While {\textexclamdown}italic{\textquestiondown}mpeZ{\textexclamdown}/italic{\textquestiondown} is expressed more in blue light than green light, this is the reverse for {\textexclamdown}italic{\textquestiondown}mpeW{\textexclamdown}/italic{\textquestiondown}, although only small phenotypic differences were found among chromatic acclimaters possessing either CA4 island type. This study provides novel insights into understanding both diversity and evolution of the CA4 process.{\textexclamdown}/p{\textquestiondown}}, keywords = {2013, MACUMBA, MicroB3, rcc, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto?app}, doi = {10.1371/journal.pone.0084459}, url = {http://dx.doi.org/10.1371/journal.pone.0084459}, author = {Humily, Florian and Partensky, Fr{\'e}d{\'e}ric and Six, Christophe and Farrant, Gregory K and Ratin, Morgane and Marie, Dominique and Garczarek, Laurence} } @article {chen_genetic_2013, title = {Genetic transformation of marine cyanobacterium Synechococcus sp. CC9311 (Cyanophyceae) by electroporation}, journal = {Chinese Journal of Oceanology and Limnology}, volume = {31}, number = {2}, year = {2013}, pages = {416{\textendash}420}, abstract = {Synechococcus sp. CC9311 is a marine cyanobacterium characterized by type IV chromatic acclimation (CA). A genetic transformation system was developed as a first step to elucidate the molecular mechanism of CA. The results show that Synechococcus sp. CC9311 cells were sensitive to four commonly used antibiotics: ampicillin, kanamycin, spectinomycin, and chloramphenicol. An integrative plasmid to disrupt the putative phycoerythrin lyase gene mpeV, using a kanamycin resistance gene as selectable marker, was constructed by recombinant polymerase chain reaction. The plasmid was then transformed into Synechococcus sp. CC9311 via electroporation. High transformation efficiency was achieved at a field strength of 2 kV/cm. DNA analysis showed that mpeV was fully disrupted following challenge of the transformants with a high concentration of kanamycin. In addition, the transformants that displayed poor growth on agar SN medium could be successfully plated on agarose SN medium.}, keywords = {RCC1086}, issn = {1993-5005}, doi = {10.1007/s00343-013-2164-5}, url = {https://doi.org/10.1007/s00343-013-2164-5}, author = {Chen, Huaxin and Lin, Hanzhi and Jiang, Peng and Li, Fuchao and Qin, Song} } @article {Collen2013, title = {Genome structure and metabolic features in the red seaweed Chondrus crispus shed light on evolution of the Archaeplastida}, journal = {Proceedings of the National Academy of Sciences}, volume = {110}, number = {13}, year = {2013}, note = {tex.mendeley-tags: RCC299}, pages = {5247{\textendash}5252}, abstract = {Red seaweeds are key components of coastal ecosystems and are economically important as food and as a source of gelling agents, but their genes and genomes have received little attention. Here we report the sequencing of the 105-Mbp genome of the florideophyte Chondrus crispus (Irish moss) and the annotation of the 9,606 genes. The genome features an unusual structure characterized by gene-dense regions surrounded by repeat-rich regions dominated by transposable elements. Despite its fairly large size, this genome shows features typical of compact genomes, e.g., on average only 0.3 introns per gene, short introns, low median distance between genes, small gene families, and no indication of large-scale genome duplication. The genome also gives insights into the metabolism of marine red algae and adaptations to the marine environment, including genes related to halogen metabolism, oxylipins, and multicellularity (microRNA processing and transcription factors). Particularly interesting are features related to carbohydrate metabolism, which include a minimalistic gene set for starch biosynthesis, the presence of cellulose synthases acquired before the primary endosymbiosis showing the polyphyly of cellulose synthesis in Archaeplastida, and cellulases absent in terrestrial plants as well as the occurrence of a mannosylglycerate synthase potentially originating from a marine bacterium. To explain the observations on genome structure and gene content, we propose an evolutionary scenario involving an ancestral red alga that was driven by early ecological forces to lose genes, introns, and intergenetic DNA; this loss was followed by an expansion of genome size as a consequence of activity of transposable elements.}, keywords = {RCC299}, doi = {10.1073/pnas.1221259110}, url = {http://www.pnas.org/content/110/13/5247.abstract}, author = {Collen, Jonas and Porcel, Betina and Carr{\'e}, Wilfrid and Ball, Steven G and Chaparro, Cristian and Tonon, Thierry and Barbeyron, Tristan and Michel, Gurvan and Noel, Benjamin and Valentin, Klaus and Elias, Marek and Artiguenave, Fran{\c c}ois and Arun, Alok and Aury, Jean-Marc and Barbosa-Neto, Jos{\'e} F and Bothwell, John H and Bouget, Fran{\c c}ois-Yves and Brillet, Loraine and Cabello-Hurtado, Francisco and Capella-Guti{\'e}rrez, Salvador and Charrier, B{\'e}n{\'e}dicte and Cladi{\`e}re, Lionel and Cock, J Mark and Coelho, Susana M and Colleoni, Christophe and Czjzek, Mirjam and Da Silva, Corinne and Delage, Ludovic and Denoeud, France and Deschamps, Philippe and Dittami, Simon M and Gabald{\'o}n, Toni and Gachon, Claire M M and Groisillier, Agn{\`e}s and Herv{\'e}, C{\'e}cile and Jabbari, Kamel and Katinka, Michael and Kloareg, Bernard and Kowalczyk, Nathalie and Labadie, Karine and Leblanc, Catherine and Lopez, Pascal J and McLachlan, Deirdre H and Meslet-Cladiere, Laurence and Moustafa, Ahmed and Nehr, Zofia and Nyvall Coll{\'e}n, Pi and Panaud, Olivier and Partensky, Fr{\'e}d{\'e}ric and Poulain, Julie and Rensing, Stefan A and Rousvoal, Sylvie and Samson, Gaelle and Symeonidi, Aikaterini and Weissenbach, Jean and Zambounis, Antonios and Wincker, Patrick and Boyen, Catherine} } @article {stuart_genomic_2013, title = {Genomic island genes in a coastal marine Synechococcus strain confer enhanced tolerance to copper and oxidative stress}, journal = {The ISME Journal}, volume = {7}, number = {6}, year = {2013}, note = {Number: 6 Publisher: Nature Publishing Group}, pages = {1139{\textendash}1149}, abstract = {Highly variable regions called genomic islands are found in the genomes of marine picocyanobacteria, and have been predicted to be involved in niche adaptation and the ecological success of these microbes. These picocyanobacteria are typically highly sensitive to copper stress and thus, increased copper tolerance could confer a selective advantage under some conditions seen in the marine environment. Through targeted gene inactivation of genomic island genes that were known to be upregulated in response to copper stress in Synechococcus sp. strain CC9311, we found two genes (sync_1495 and sync_1217) conferred tolerance to both methyl viologen and copper stress in culture. The prevalence of one gene, sync_1495, was then investigated in natural samples, and had a predictable temporal variability in abundance at a coastal monitoring site with higher abundance in winter months. Together, this shows that genomic island genes can confer an adaptive advantage to specific stresses in marine Synechococcus, and may help structure their population diversity.}, keywords = {RCC1086}, issn = {1751-7370}, doi = {10.1038/ismej.2012.175}, url = {http://www.nature.com/articles/ismej2012175}, author = {Stuart, Rhona K. and Brahamsha, Bianca and Busby, Kayla and Palenik, Brian} } @article {Chamnansinp2013, title = {Global diversity of two widespread, colony-forming diatoms of the marine plankton, Chaetoceros socialis (syn. C. radians ) and Chaetoceros gelidus sp. nov.}, journal = {Journal of Phycology}, volume = {49}, number = {6}, year = {2013}, note = {ISBN: 1529-8817 tex.mendeley-tags: RCC3007}, month = {dec}, pages = {1128{\textendash}1141}, keywords = {Arctic, Biogeography, Chaetoceros gelidus sp. nov., Chaetoceros radians, Chaetoceros socialis, Diatom, Distribution, Global, phylogeny, RCC3007}, issn = {00223646}, doi = {10.1111/jpy.12121}, url = {http://doi.wiley.com/10.1111/jpy.12121}, author = {Chamnansinp, Atchaneey and Li, Yang and Lundholm, Nina and Moestrup, {\O}jvind}, editor = {Bowler, C.} } @article {Subirana2013, title = {Morphology, genome plasticity, and phylogeny in the genus ostreococcus reveal a cryptic species, o. mediterraneus sp. nov. (mamiellales, mamiellophyceae)}, journal = {Protist}, volume = {164}, number = {5}, year = {2013}, note = {tex.mendeley-tags: RCC1112,RCC1114,RCC1117,RCC143,RCC1620,RCC1621,RCC1623,RCC1624,RCC2572,RCC2573,RCC2574,RCC2575,RCC2577,RCC2578,RCC2579,RCC2582,RCC2583,RCC2584,RCC2585,RCC2587,RCC2590,RCC344,RCC356,RCC393,RCC501,RCC745,RCC809}, pages = {643{\textendash}659}, abstract = {Coastal marine waters in many regions worldwide support abundant populations of extremely small (1-3 ??m diameter) unicellular eukaryotic green algae, dominant taxa including several species in the class Mamiellophyceae. Their diminutive size conceals surprising levels of genetic diversity and defies classical species{\textquoteright} descriptions. We present a detailed analysis within the genus Ostreococcus and show that morphological characteristics cannot be used to describe diversity within this group. Karyotypic analyses of the best-characterized species O. tauri show it to carry two chromosomes that vary in size between individual clonal lines, probably an evolutionarily ancient feature that emerged before species{\textquoteright} divergences within the Mamiellales. By using a culturing technique specifically adapted to members of the genus Ostreococcus, we purified {\textquestiondown}30 clonal lines of a new species, Ostreococcus mediterraneus sp. nov., previously known as Ostreococcus clade D, that has been overlooked in several studies based on PCR-amplification of genetic markers from environment-extracted DNA. Phylogenetic analyses of the S-adenosylmethionine synthetase gene, and of the complete small subunit ribosomal RNA gene, including detailed comparisons of predicted ITS2 (internal transcribed spacer 2) secondary structures, clearly support that this is a separate species. In addition, karyotypic analyses reveal that the chromosomal location of its ribosomal RNA gene cluster differs from other Ostreococcus clades.}, keywords = {barcode, Chromosome, culture, ITS2, karyotype, picoeukaryote, rcc, RCC1112, RCC1114, RCC1117, RCC143, RCC1620, RCC1621, RCC1623, RCC1624, RCC2572, RCC2573, RCC2574, RCC2575, RCC2577, RCC2578, RCC2579, RCC2582, RCC2583, RCC2584, RCC2585, RCC2587, RCC2590, RCC344, RCC356, RCC393, rcc501, RCC745, RCC809, ribosomal gene}, doi = {10.1016/j.protis.2013.06.002}, url = {http://www.sciencedirect.com/science/article/pii/S1434461013000497}, author = {Subirana, Lucie and P{\'e}quin, B{\'e}rang{\`e}re and Michely, St{\'e}phanie and Escande, Marie-Line and Meilland, Julie and Derelle, Evelyne and Marin, Birger and Piganeau, Gwenael and Desdevises, Yves and Moreau, Herv{\'e} and Grimsley, Nigel H} } @article {Blanc-Mathieu2013, title = {Organellar inheritance in the green lineage: Insights from ostreococcus tauri}, journal = {Genome Biology and Evolution}, volume = {5}, number = {8}, year = {2013}, note = {tex.mendeley-tags: RCC1108,RCC1110,RCC1112,RCC1114,RCC1115,RCC1116,RCC1117,RCC1118,RCC1123,RCC1558,RCC1559,RCC1561,RCC745}, pages = {1503{\textendash}1511}, abstract = {Along the green lineage (Chlorophyta and Streptophyta), mitochondria and chloroplast are mainly uniparentally transmitted and their evolution is thus clonal. The mode of organellar inheritance in their ancestor is less certain. The inability to make clear phylogenetic inference is partly due to a lack of information for deep branching organisms in this lineage. Here, we investigate organellar evolution in the early branching green alga Ostreococcus tauri using population genomics data from the complete mitochondrial and chloroplast genomes. The haplotype structure is consistent with clonal evolution in mitochondria, while we find evidence for recombination in the chloroplast genome. The number of recombination events in the genealogy of the chloroplast suggests that recombination, and thus biparental inheritance, is not rare. Consistent with the evidence of recombination, we find that the ratio of the number of nonsynonymous to the synonymous polymorphisms per site is lower in chloroplast than in the mitochondria genome. We also find evidence for the segregation of two selfish genetic elements in the chloroplast. These results shed light on the role of recombination and the evolutionary history of organellar inheritance in the green lineage.}, keywords = {rcc, RCC1108, RCC1110, RCC1112, RCC1114, RCC1115, RCC1116, RCC1117, RCC1118, RCC1123, RCC1558, RCC1559, RCC1561, RCC745}, doi = {10.1093/gbe/evt106}, url = {http://gbe.oxfordjournals.org/content/5/8/1503.abstract}, author = {Blanc-Mathieu, Romain and Sanchez-Ferandin, Sophie and Eyre-Walker, Adam and Piganeau, Gwenael} } @article {Shukla2013, title = {Phycoerythrin-specific bilin lyase{\textendash}isomerase controls blue-green chromatic acclimation in marine Synechococcus}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, year = {2013}, note = {tex.mendeley-tags: 2013,rcc,sbr?hyto?app}, pages = {20136{\textendash}20141}, keywords = {2013, rcc, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto?app}, doi = {10.1073/pnas.1211777109}, author = {Shukla, A and Biswas, A and Blot, N and Partensky, F and Karty, J A and Hammad, L A and Garczarek, L and Gutu, A and Schluchter, W M and Kehoe, D M} } @article {Vandepoele2013, title = {pico-PLAZA, a genome database of microbial photosynthetic eukaryotes}, journal = {Environmental Microbiology}, volume = {15}, number = {8}, year = {2013}, note = {tex.mendeley-tags: Micromonas,rcc}, pages = {2147{\textendash}2153}, abstract = {With the advent of next generation genome sequencing, the number of sequenced algal genomes and transcriptomes is rapidly growing. Although a few genome portals exist to browse individual genome sequences, exploring complete genome information from multiple species for the analysis of user-defined sequences or gene lists remains a major challenge. pico-PLAZA is a web-based resource (http://bioinformatics.psb.ugent.be/pico-plaza/) for algal genomics that combines different data types with intuitive tools to explore genomic diversity, perform integrative evolutionary sequence analysis and study gene functions. Apart from homologous gene families, multiple sequence alignments, phylogenetic trees, Gene Ontology, InterPro and text-mining functional annotations, different interactive viewers are available to study genome organization using gene collinearity and synteny information. Different search functions, documentation pages, export functions and an extensive glossary are available to guide non-expert scientists. To illustrate the versatility of the platform, different case studies are presented demonstrating how pico-PLAZA can be used to functionally characterize large-scale EST/RNA-Seq data sets and to perform environmental genomics. Functional enrichments analysis of 16 Phaeodactylum tricornutum transcriptome libraries offers a molecular view on diatom adaptation to different environments of ecological relevance. Furthermore, we show how complementary genomic data sources can easily be combined to identify marker genes to study the diversity and distribution of algal species, for example in metagenomes, or to quantify intraspecific diversity from environmental strains.}, keywords = {Micromonas, rcc}, doi = {10.1111/1462-2920.12174}, url = {http://dx.doi.org/10.1111/1462-2920.12174}, author = {Vandepoele, Klaas and Van Bel, Michiel and Richard, Guilhem and Van Landeghem, Sofie and Verhelst, Bram and Moreau, Herv{\'e} and Van de Peer, Yves and Grimsley, Nigel and Piganeau, Gwenael} } @article {Guillou2013, title = {The protist ribosomal reference database (PR2): a catalog of unicellular eukaryote small SubUnit rRNA sequences with curated taxonomy}, journal = {Nucleic Acids Research}, volume = {41}, year = {2013}, note = {tex.mendeley-tags: 2013,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?ppo}, pages = {D597{\textendash}D604}, keywords = {2013, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto$_\textrmd$ipo, sbr?hyto?ppo}, doi = {10.1093/nar/gks1160}, author = {Guillou, Laure and Bachar, Dipankar and Audic, St{\'e}phane and Bass, David and Berney, Cedric and Bittner, Lucie and Boutte, Christophe and Burgaud, Gaetan and de Vargas, Colomban and Decelle, Johan and del Campo, Javier and Dolan, John and Dunthorn, Micah and Bente, Edvardsen and Holzmann, Maria and Kooistra, Wiebe H C F and Lara, Enrique and Lebescot, Noan and Logares, Ramiro and Mah{\'e}, Fr{\'e}d{\'e}ric and Massana, Ramon and Montresor, Marina and Morard, Raphael and Not, Fabrice and Pawlowski, Jan and Probert, Ian and Sauvadet, Anne-Laure and Siano, Raffaele and Stoeck, Thorsten and Vaulot, Daniel and Zimmermann, Pascal and Christen, Richard} } @article {Drescher2012, title = {Coccolithogenesis in scyphosphaera apsteinii (prymnesiophyceae)}, journal = {Journal of Phycology}, volume = {48}, number = {6}, year = {2012}, note = {tex.mendeley-tags: RCC1456}, pages = {1343{\textendash}1361}, abstract = {Coccolithophores are the most significant producers of marine biogenic calcite, although the intracellular calcification process is poorly understood. In the case of Scyphosphaera apsteinii Lohmann 1902, flat ovoid muroliths and bulky, vase-shaped lopadoliths with a range of intermediate morphologies may be produced by a single cell. This polymorphic species is within the Zygodiscales, a group that remains understudied with respect to ultrastructure and coccolith ontogeny. We therefore undertook an analysis of cell ultrastructure, morphology, and coccolithogenesis. The cell ultrastructure showed many typical haptophyte features, with calcification following a similar pattern to that described for other heterococcolith bearing species including Emiliania huxleyi. Of particular significance was the reticular body role in governing fine-scale morphology, specifically the central pore formation of the coccolith. Our observations also highlighted the essential role of the inter- and intracrystalline organic matrix in growth and arrangement of the coccolith calcite. S. apsteinii secreted mature coccoliths that attached to the plasma membrane via fibrillar material. Time-lapse light microscopy demonstrated secretion of lopadoliths occurred base first before being actively repositioned at the cell surface. Significantly, growth irradiance influenced the coccosphere composition with fewer lopadoliths being formed relative to muroliths at higher light intensities. Overall, our observations support dynamic metabolic (i.e., in response to growth irradiance), sensory and cytoskeletal control over the morphology and secretion of polymorphic heterococcoliths. With a basic understanding of calcification established, S. apsteinii could be a valuable model to further study coccolithophore calcification and cell physiological responses to ocean acidification.}, keywords = {Calcification, coccolithogenesis, coccolithophore, organic matrix, rcc, RCC1456, reticular body, secretion, ultrastructure, Zygodiscales}, doi = {10.1111/j.1529-8817.2012.01227.x}, url = {http://dx.doi.org/10.1111/j.1529-8817.2012.01227.x}, author = {Drescher, Brandon and Dillaman, Richard M and Taylor, Alison R} } @article {Balzano2012, title = {Composition of the summer photosynthetic pico and nanoplankton communities in the Beaufort Sea assessed by T-RFLP and sequences of the 18S rRNA gene from flow cytometry sorted samples}, journal = {The ISME journal}, volume = {6}, number = {8}, year = {2012}, note = {ISBN: 1751-7362 tex.mendeley-tags: 2012,rcc,sbr?hyto$_\textrmd$ipo}, pages = {1480{\textendash}1498}, abstract = {The composition of photosynthetic pico and nanoeukaryotes was investigated in the North East Pacific and the Arctic Ocean with special emphasis on the Beaufort Sea during the MALINA cruise in summer 2009. Photosynthetic populations were sorted using flow cytometry based on their size and pigment fluorescence. Diversity of the sorted photosynthetic eukaryotes was determined using terminal-restriction fragment length polymorphism analysis and cloning/sequencing of the 18S ribosomal RNA gene. Picoplankton was dominated by Mamiellophyceae, a class of small green algae previously included in the prasinophytes: in the North East Pacific, the contribution of an Arctic Micromonas ecotype increased steadily northward becoming the only taxon occurring at most stations throughout the Beaufort Sea. In contrast, nanoplankton was more diverse: North Pacific stations were dominated by Pseudo-nitzschia sp. whereas those in the Beaufort Sea were dominated by two distinct Chaetoceros species as well as by Chrysophyceae, Pelagophyceae and Chrysochromulina spp.. This study confirms the importance of Arctic Micromonas within picoplankton throughout the Beaufort Sea and demonstrates that the photosynthetic picoeukaryote community in the Arctic is much less diverse than at lower latitudes. Moreover, in contrast to what occurs in warmer waters, most of the key pico- and nanoplankton species found in the Beaufort Sea could be successfully established in culture.}, keywords = {2012, ASSEMBLE, Chaetoceros, MALINA, Pyramimonas, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, Souchotheque}, issn = {1751-7362}, doi = {10.1038/ismej.2011.213}, author = {Balzano, Sergio and Marie, Dominique and Gourvil, Priscillia and Vaulot, Daniel} } @article {Balzano2012a, title = {Diversity of cultured photosynthetic flagellates in the North East Pacific and Arctic Oceans in summer}, journal = {Biogeosciences}, volume = {9}, year = {2012}, note = {tex.mendeley-tags: 2012,macumba,rcc,sbr?hyto$_\textrmd$ipo}, pages = {4553{\textendash}4571}, keywords = {2012, ASSEMBLE, MACUMBA, MALINA, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.5194/bg-9-4553-2012}, author = {Balzano, Sergio and Gourvil, Priscillia and Siano, Raffaele and Chanoine, M{\'e}lanie and Marie, Dominique and Lessard, Sylvie and Sarno, Diana and Vaulot, Daniel} } @article {Stern2012, title = {Evaluating the ribosomal internal transcribed spacer (ITS) as a candidate dinoflagellate barcode marker}, journal = {PLoS ONE}, volume = {7}, year = {2012}, note = {tex.mendeley-tags: 2012,rcc,sbr?hyto$_\textrmd$ipo}, pages = {e42780}, keywords = {2012, ASSEMBLE, Barcoding, ITS, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.1371/journal.pone.0042780}, url = {http://www.plosone.org/article/info\%253Adoi\%252F10.1371\%252Fjournal.pone.0042780}, author = {Stern, Rowena F and Andersen, Robert A and Jameson, Ian and K{\"u}pper, Frithjof C and Coffroth, Mary-Alice and Vaulot, Daniel and Gall, Florence Le and Veron, Benoit and Brand, Jerry J and Skelton, Hayley and Kasai, Fumai and Lilly, Emily L and Keeling, Patrick J} } @article {Giovagnetti2012, title = {Growth and photophysiological responses of two picoplanktonic {\textexclamdown}i{\textquestiondown}Minutocellus species{\textexclamdown}/i{\textquestiondown}, strains RCC967 and RCC703 (Bacillariophyceae)}, journal = {European Journal of Phycology}, volume = {47}, number = {4}, year = {2012}, note = {ISBN: 0967-0262 tex.mendeley-tags: rcc703,rcc967}, pages = {408{\textendash}420}, abstract = {Reaching up to 50\% of the total biomass in oligotrophic waters and armed with a set of ecological and biological properties related to their small size, picophytoplankton ({\textexclamdown}3.0 mm) are a good model to address ecophysiological questions regarding phytoplankton biodiversity. Two picoplanktonic diatoms, one isolated from an upwelling ecosystem in the Pacific Ocean (Minutocellus sp., strain RCC967), and another from oceanic waters in the Indian Ocean (Minutocellus sp., strain RCC703) were used to test hypotheses on the functional relation between ecological niche adaptation and photosynthetic regulation capacity and efficiency. Cultures were subjected to five sine light climates, each one set to peak at a different photon flux density, respectively 10, 50, 100, 250 and 500 mmol photons m(-2) s(-1). Growth rate, photosynthesis, non-photochemical fluorescence quenching, pigment composition, and particulate organic carbon and nitrogen content were followed daily for 5 days. Growth rate and physiological response curves were different in the two species, in agreement with their distinct habitats of origin. Such differences could be related to the diverse photoacclimative strategies displayed by the two species, revealing a clear adaptive divergence despite their close taxonomic relationship. Photoacclimative strategies of the two picoplanktonic diatoms are discussed in the light of functional diversity and ecosystem adaptation.}, keywords = {carbon, diatoms, elemental stoichiometry, fluctuating light, marine-phytoplankton, non-photochemical fluorescence quenching, phaeodactylum-tricornutum, photoacclimation, photoprotection, photoregulation, Photosynthesis, picoeukaryotes, planktonic diatoms, rcc703, rcc967, RCC?o?dd, violaxanthin cycle, Xanthophyll cycle, xanthophyll-cycle activity}, doi = {10.1080/09670262.2012.733030}, author = {Giovagnetti, V and Cataldo, M L and Conversano, F and Brunet, C} } @article {Frada2012, title = {In situ survey of life cycle phases of the coccolithophore Emiliania huxleyi (Haptophyta)}, journal = {Environmental Microbiology}, volume = {14}, number = {6}, year = {2012}, note = {Publisher: Blackwell Publishing Ltd tex.mendeley-tags: 2012,rcc,sbr?hyto?ppo}, pages = {1558{\textendash}1569}, abstract = {The cosmopolitan coccolithophore Emiliania huxleyi is characterized by a strongly differentiated haplodiplontic life cycle consisting of a diploid phase, generally bearing coccoliths (calcified) but that can be also non-calcified, and a non-calcified biflagellated haploid phase. Given most studies have focused on the bloom-producing calcified phase, there is little-to-no information about non-calcified cells in nature. Using field mesocoms as experimental platforms, we quantitatively surveyed calcified and non-calcified cells using the combined calcareous detection fluorescent in situ hybridization (COD-FISH) method and qualitatively screened for haploid specific transcripts using reverse transcription-PCR during E. huxleyi bloom successions. Diploid, calcified cells formed dense blooms that were followed by the massive proliferation of E. huxleyi viruses (EhVs), which caused bloom demise. Non-calcified cells were also detected throughout the experiment, accounting for a minor fraction of the population but becoming progressively more abundant during mid-late bloom periods concomitant with EhV burst. Non-calcified cell growth also paralleled a distinct window of haploid-specific transcripts and the appearance of autotrophic flagellates morphologically similar to haploid cells, both of which are suggestive of meiosis and sexual life cycling during natural blooms of this prominent marine phytoplankton species.}, keywords = {2012, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1111/j.1462-2920.2012.02745.x}, url = {http://dx.doi.org/10.1111/j.1462-2920.2012.02745.x}, author = {Frada, Miguel J and Bidle, Kay D and Probert, Ian and de Vargas, Colomban} } @article {Ota2012, title = {Lotharella reticulosa sp. nov.: A highly reticulated network forming chlorarachniophyte from the mediterranean sea}, journal = {Protist}, volume = {163}, number = {1}, year = {2012}, note = {tex.mendeley-tags: RCC375,RCC376}, pages = {91{\textendash}104}, abstract = {A new chlorarachniophyte Lotharella reticulosa sp. nov. is described from a culture isolated from the Mediterranean Sea. This strain is maintained as strain RCC375 at the Roscoff Culture Collection, France. This species presents a multiphasic life cycle: vegetative cells of this species were observed to be coccoid, but amoeboid cells with filopodia and globular suspended cells were also present in the life cycle, both of which were not dominant phases. Flagellate cells were also observed but remained very rare in culture. The vegetative cells were 9-16 ??m in diameter and highly vacuolated, containing several green chloroplasts with a projecting pyrenoid, mitochondria, and a nucleus. The chloroplast was surrounded by four membranes possessing a nucleomorph in the periplastidial compartment near the pyrenoid base. According to ultrastructural observations of the pyrenoid and nucleomorph, the present species belongs to the genus Lotharella in the phylum Chlorarachniophyta. This taxonomic placement is consistent with the molecular phylogenetic trees of the 18S rRNA gene and ITS sequences. This species showed a unique colonization pattern. Clusters of cells extended cytoplasmic strands radially. Then, amoeboid cells being born proximately moved distally along the cytoplasmic strand like on a "railway track" Subsequently the amoeboid cell became coccoid near the strand. In this way, daughter cells were dispersed evenly on the substratum. We also observed that the present species regularly formed a structure of filopodial nodes in mid-stage and later-stage cultures, which is a novel phenotype in chlorarachniophytes. The unique colonization pattern and other unique features demonstrate that RCC375 is a new chlorarachniophyte belonging to genus Lotharella, which we describe as Lotharella reticulosa sp. nov. ?? 2011 Elsevier GmbH.}, keywords = {Chlorarachniophytes, Lotharella, Mediterranean Sea, RCC375, RCC376, Taxonomy.}, author = {Ota, Shuhei and Vaulot, Daniel} } @article {Zeng2012, title = {Marine viruses exploit their host{\textquoteright}s two-component regulatory system in response to resource limitation}, journal = {Current Biology}, year = {2012}, note = {Publisher: Cell Press tex.mendeley-tags: rcc}, abstract = {Phosphorus (P) availability, which often limits productivity in marine ecosystems, shapes the P-acquisition gene content of the marine cyanobacteria Prochlorococcus [1 4] and its viruses (cyanophages) [5, 6]. As in other bacteria, in Prochlorococcus these genes are regulated by the PhoR/PhoB two-component regulatory system that is used to sense and respond to P availability and is typical of signal transduction systems found in diverse organisms [7]. Replication of cyanophage genomes requires a significant amount of P, and therefore these phages could gain a fitness advantage by influencing host P acquisition in P-limited environments. Here we show that the transcription of a phage-encoded high-affinity phosphate-binding protein gene (pstS) and alkaline phosphatase gene (phoA) both of which have host orthologs is elevated when the phages are infecting host cells that are P starved, relative to P-replete control cells. We further show that the phage versions of these genes are regulated by the host{\textquoteright}s PhoR/PhoB system. This not only extends this fundamental signaling mechanism to viruses but is also the first example of regulation of lytic phage genes by nutrient limitation in the host. As such, it reveals an important new dimension of the intimate coevolution of phage, host, and environment in the world{\textquoteright}s oceans. {\textordmasculine} Phage production, but not lytic cycle, is reduced in P-starved host cells {\textordmasculine} Transcription of phage P acquisition genes is upregulated in P-starved hosts {\textordmasculine} Phage P-acquisition genes are regulated by the host PhoR/PhoB two-component system {\textordmasculine} This is the first incidence of regulation of virus genes by a two-component system}, keywords = {NATL2A, rcc, RCC?o?dd}, doi = {10.1016/j.cub.2011.11.055}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0960982211013704}, author = {Zeng, Qinglu and Chisholm, Sallie W} } @article {Decelle2012, title = {An original mode of symbiosis in open ocean plankton}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, year = {2012}, note = {tex.mendeley-tags: 2012,rcc,sbr?hyto?ppo}, pages = {18000{\textendash}18005}, keywords = {2012, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1073/pnas.1212303109}, author = {Decelle, J and Probert, I and Bittner, L and Desdevises, Y and Colin, S and de Vargas, C and Gali, M and Simo, R and Not, F} } @article {Monier2012, title = {Phosphate transporters in marine phytoplankton and their viruses: cross-domain commonalities in viral-host gene exchanges}, journal = {Environmental Microbiology}, volume = {14}, number = {1}, year = {2012}, note = {Publisher: Blackwell Publishing Ltd tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {162{\textendash}176}, abstract = {Phosphate (PO4) is an important limiting nutrient in marine environments. Marine cyanobacteria scavenge PO4 using the high-affinity periplasmic phosphate binding protein PstS. The pstS gene has recently been identified in genomes of cyanobacterial viruses as well. Here, we analyse genes encoding transporters in genomes from viruses that infect eukaryotic phytoplankton. We identified inorganic PO4 transporter-encoding genes from the PHO4 superfamily in several virus genomes, along with other transporter-encoding genes. Homologues of the viral pho4 genes were also identified in genome sequences from the genera that these viruses infect. Genome sequences were available from host genera of all the phytoplankton viruses analysed except the host genus Bathycoccus. Pho4 was recovered from Bathycoccus by sequencing a targeted metagenome from an uncultured Atlantic Ocean population. Phylogenetic reconstruction showed that pho4 genes from pelagophytes, haptophytes and infecting viruses were more closely related to homologues in prasinophytes than to those in what, at the species level, are considered to be closer relatives (e.g. diatoms). We also identified PHO4 superfamily members in ocean metagenomes, including new metagenomes from the Pacific Ocean. The environmental sequences grouped with pelagophytes, haptophytes, prasinophytes and viruses as well as bacteria. The analyses suggest that multiple independent pho4 gene transfer events have occurred between marine viruses and both eukaryotic and bacterial hosts. Additionally, pho4 genes were identified in available genomes from viruses that infect marine eukaryotes but not those that infect terrestrial hosts. Commonalities in marine host-virus gene exchanges indicate that manipulation of host-PO4 uptake is an important adaptation for viral proliferation in marine systems. Our findings suggest that PO4-availability may not serve as a simple bottom-up control of marine phytoplankton.}, keywords = {Micromonas, rcc}, doi = {10.1111/j.1462-2920.2011.02576.x}, url = {http://dx.doi.org/10.1111/j.1462-2920.2011.02576.x}, author = {Monier, Adam and Welsh, Rory M and Gentemann, Chelle and Weinstock, George and Sodergren, Erica and Armbrust, E Virginia and Eisen, Jonathan A and Worden, Alexandra Z} } @article {Treusch2012, title = {Phytoplankton distribution patterns in the northwestern Sargasso Sea revealed by small subunit rRNA genes from plastids}, journal = {The ISME journal}, volume = {6}, year = {2012}, note = {Publisher: International Society for Microbial Ecology tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {481{\textendash}492}, keywords = {Bathycoccus, CHRYSOPHYCEAE, key?aper, Micromonas, Ostreococcus, pelagophyceae, Prasinophyceae, Prymnesiophyceae, QPCR, rcc, TRFLP}, doi = {10.1038/ismej.2011.117}, url = {http://dx.doi.org/10.1038/ismej.2011.117 http://www.nature.com/ismej/journal/vaop/ncurrent/suppinfo/ismej2011117s1.html}, author = {Treusch, Alexander H and Demir-Hilton, Elif and Vergin, Kevin L and Worden, Alexandra Z and Carlson, Craig A and Donatz, Michael G and Burton, Robert M and Giovannoni, Stephen J} } @article {Clerissi2012, title = {Prasinoviruses of the marine green alga Ostreococcus tauri are mainly species specific}, journal = {Journal of Virology}, volume = {86}, number = {8}, year = {2012}, note = {tex.mendeley-tags: RCC1110,RCC1114,RCC1115,RCC1116,RCC1117,RCC1123,RCC1558,RCC1561,RCC745}, pages = {4611{\textendash}4619}, abstract = {Prasinoviruses infecting unicellular green algae in the order Mamiellales (class Mamiellophyceae) are commonly found in coastal marine waters where their host species frequently abound. We tested 40 Ostreococcus tauri viruses on 13 independently isolated wild-type O. tauri strains, 4 wild-type O. lucimarinus strains, 1 Ostreococcus sp. ({\textquotedblleft}Ostreococcus mediterraneus{\textquotedblright}) clade D strain, and 1 representative species of each of two other related species of Mamiellales, Bathycoccus prasinos and Micromonas pusilla. Thirty-four out of 40 viruses infected only O. tauri, 5 could infect one other species of the Ostreococcus genus, and 1 infected two other Ostreococcus spp., but none of them infected the other genera. We observed that the overall susceptibility pattern of Ostreococcus strains to viruses was related to the size of two host chromosomes known to show intraspecific size variations, that genetically related viruses tended to infect the same host strains, and that viruses carrying inteins were strictly strain specific. Comparison of two complete O. tauri virus proteomes revealed at least three predicted proteins to be candidate viral specificity determinants.}, keywords = {rcc, RCC1110, RCC1114, RCC1115, RCC1116, RCC1117, RCC1123, RCC1558, RCC1561, RCC745}, issn = {0022-538X}, doi = {10.1128/jvi.07221-11}, url = {http://jvi.asm.org/content/86/8/4611.abstract}, author = {Clerissi, Camille and Desdevises, Yves and Grimsley, Nigel} } @article {Baines2012, title = {Significant silicon accumulation by marine picocyanobacteria}, journal = {Nature Geoscience}, volume = {5}, number = {12}, year = {2012}, note = {arXiv: 9605103 [cs] ISBN: 1752-08941?752-0908 Publisher: Nature Publishing Group tex.arxivid: cs/9605103 tex.mendeley-tags: rcc1084,rcc1086,rcc752}, pages = {886{\textendash}891}, abstract = {The marine silicon cycle is thought to be intimately tied to the carbon cycle through its effect on the growth of diatoms. These unicellular algae form substantial blooms in cold, nutrient-rich waters. Their dense, siliceous cell walls promote the sinking of particulate matter, and all the carbon and nutrients contained therein1. As such, diatoms are thought to be the primary organisms responsible for the low levels of dissolved silicon observed in the surface ocean and the export of mineral silica to depth. Here, we use synchrotron X-ray fluorescence microscopy to determine the elemental composition of individual diatoms and cyanobacterial cells from the eastern equatorial Pacific and the Sargasso Sea.We show that cells of Synechococcus, a small unicellular marine cyanobacterium that dominates in nutrient-depleted waters2, can exhibit cellular ratios of silicon to sulphur, and silicon to phosphorus, approaching those detected in diatoms in the same location. Silicon accumulation was also observed in cultured Synechococcus strains. We estimate that the water column inventory of silicon in Synechococcus can exceed that of diatomsinsomecases.We suggest that picocyanobacteriamay exert a previously unrecognized influence on the oceanic silicon cycle, especially in nutrient-poorwaters.}, keywords = {rcc1084, RCC1086, rcc752}, issn = {1752-0894}, doi = {10.1038/ngeo1641}, url = {http://www.nature.com/doifinder/10.1038/ngeo1641}, author = {Baines, Stephen B. and Twining, Benjamin S. and Brzezinski, Mark a. and Krause, Jeffrey W. and Vogt, Stefan and Assael, Dylan and McDaniel, Hannah} } @article {Kulk2012, title = {Temperature-dependent growth and photophysiology of prokaryotic and eukaryotic oceanic picophytoplankton}, journal = {Marine Ecology Progress Series}, volume = {466}, year = {2012}, note = {tex.mendeley-tags: RCC407,RCC410,RCC879}, pages = {43{\textendash}55}, abstract = {ABSTRACT: It is expected that climate change will expand the open oligotrophic oceans by enhanced thermal stratification. Because temperature defines the geographic distribution of picophytoplankton in open-ocean ecosystems and regulates photophysiological responses, it is important to understand how temperature affects picophytoplankton growth and photophysiology. Two prokaryotic and 2 eukaryotic picophytoplankton strains were acclimated to 3 different temperatures, ranging from 16 to 24{\textdegree}C. Temperature-dependent growth and photophysiology were assessed by measurements of specific growth rates, cell size, pigment composition, absorption and electron transport rates. Growth of Prochlorococcus marinus (eMED4), Prochlorococcus sp. (eMIT9313), Ostreococcus sp. (clade B) and Pelagomonas calceolata was positively related to temperature, especially in the prokaryotic strains. Changes in photophysiology included increased light harvesting, increased electron transport and reduced photoinhibition at elevated temperatures. However, the changes related to light harvesting and electron transport could not fully explain the observed difference in growth. This suggests that other processes, such as Calvin cycle activity, are likely to limit growth at sub-optimal temperatures in these picophytoplankton strains. The overall changes in photophysiology during temperature acclimation will possibly allow photosynthesis at higher irradiance intensities, but the genetically defined low temperature tolerances and photosynthetic characteristics of the different ecotypes will likely be more important in determining picophytoplankton (depth) distribution and community composition.}, keywords = {Absorption, Electron transport rate, Eukaryotic picophytoplankton, Growth, Pigment, Prochlorococcus, rcc, RCC407, rcc410, RCC879, temperature}, issn = {01718630}, doi = {10.3354/meps09898}, url = {http://www.int-res.com/abstracts/meps/v466/p43-55/}, author = {Kulk, Gemma and De Vries, Pablo and Van De Poll, Willem H. and Visser, Ronald J W and Buma, Anita G J} } @article {Thompson2012, title = {Unicellular cyanobacterium symbiotic with a single-celled eukaryotic alga}, journal = {Science}, volume = {337}, number = {6101}, year = {2012}, note = {tex.mendeley-tags: 2012,microb3,rcc,sbr?hyto$_\textrmd$ipo}, pages = {1546{\textendash}1550}, abstract = {Symbioses between nitrogen (N)2{\textendash}fixing prokaryotes and photosynthetic eukaryotes are important for nitrogen acquisition in N-limited environments. Recently, a widely distributed planktonic uncultured nitrogen-fixing cyanobacterium (UCYN-A) was found to have unprecedented genome reduction, including the lack of oxygen-evolving photosystem II and the tricarboxylic acid cycle, which suggested partnership in a symbiosis. We showed that UCYN-A has a symbiotic association with a unicellular prymnesiophyte, closely related to calcifying taxa present in the fossil record. The partnership is mutualistic, because the prymnesiophyte receives fixed N in exchange for transferring fixed carbon to UCYN-A. This unusual partnership between a cyanobacterium and a unicellular alga is a model for symbiosis and is analogous to plastid and organismal evolution, and if calcifying, may have important implications for past and present oceanic N2 fixation.}, keywords = {2012, MicroB3, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.1126/science.1222700}, url = {http://www.sciencemag.org/content/337/6101/1546.abstract}, author = {Thompson, Anne W and Foster, Rachel A and Krupke, Andreas and Carter, Brandon J and Musat, Niculina and Vaulot, Daniel and Kuypers, Marcel M M and Zehr, Jonathan P} } @article {Kirkham2011, title = {Basin-scale distribution patterns of photosynthetic picoeukaryotes along an Atlantic Meridional Transect}, journal = {Environmental Microbiology}, volume = {13}, number = {4}, year = {2011}, note = {Publisher: Blackwell Publishing Ltd tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {975{\textendash}990}, abstract = {Summary Photosynthetic picoeukaryotes (PPEs) of a size {\textexclamdown} 3 {\textmu}m play a crucial role in oceanic primary production. However, little is known of the structure of the PPE community over large spatial scales. Here, we investigated the distribution of various PPE classes along an Atlantic Meridional Transect sampled in boreal autumn 2004 that encompasses a range of ocean provinces (gyres, upwelling, temperate regions), using dot blot hybridization technology targeting plastid 16S rRNA gene amplicons. Two algal classes, Prymnesiophyceae and Chrysophyceae, dominated the PPE community throughout the Atlantic Ocean, over a range of water masses presenting different trophic profiles. However, these classes showed strongly complementary distributions with Chrysophyceae dominating northern temperate waters, the southern gyre and equatorial regions, while prymnesiophytes dominated the northern gyre. Phylogenetic analyses using both plastid and nuclear rRNA genes revealed a high diversity among members of both classes, including sequences contained in lineages with no close cultured counterpart. Other PPE classes were less prevalent along the transect, with members of the Cryptophyceae, Pelagophyceae and Eustigmatophyceae essentially restricted to specific regions. Multivariate statistical analyses revealed strong relationships between the distribution patterns of some of these latter PPE classes and temperature, light intensity and nutrient concentrations. Cryptophyceae, for example, were mostly found in the upwelling region and associated with higher nutrient concentrations. However, the key classes of Prymnesiophyceae and Chrysophyceae were not strongly influenced by the variables measured. Although there appeared to be a positive relationship between Chrysophyceae distribution and light intensity, the complementary distributions of these classes could not be explained by the variables recorded and this requires further explanation.}, keywords = {Micromonas, rcc}, doi = {10.1111/j.1462-2920.2010.02403.x}, url = {http://dx.doi.org/10.1111/j.1462-2920.2010.02403.x}, author = {Kirkham, Amy R and Jardillier, Ludwig E and Tiganescu, Ana and Pearman, John and Zubkov, Mikhail V and Scanlan, David J} } @article {Guillou2011, title = {Characterization of the Parmales: much more than the resolution of a taxonomic enigma}, journal = {Journal of Phycology}, volume = {47}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc,sbr?hyto$_\textrmd$ipo}, pages = {2{\textendash}4}, keywords = {2011, rcc, SBR$_\textrmP$hyto, sbr?hyto$_\textrmd$ipo}, doi = {10.1111/j.1529-8817.2010.00951.x}, author = {Guillou, L} } @article {Langer2011a, title = {CO2 mediation of adverse effects of seawater acidification in Calcidiscus leptoporus}, journal = {Geochemistry Geophysics Geosystems}, volume = {12}, number = {5}, year = {2011}, note = {ISBN: 1525-2027 tex.mendeley-tags: 2011,RCC1135,rcc}, pages = {1{\textendash}8}, abstract = {The coccolithophore Calcidiscus leptoporus (strain RCC1135) was grown in dilute batch culture at CO2 levels ranging from \~200 to \~1600 matm. Increasing CO2 concentration led to an increased percentage of malformed coccoliths and eventually (at \~1500 matm CO2) to aggregation of cells. Carbonate chemistry of natural seawater was manipulated in three ways: first, addition of acid; second, addition of a HCO3 -/CO3 2- solution; and third, addition of both acid and HCO3 -/CO32- solution. The data set allowed the disentangling of putative effects of the different parameters of the carbonate system. It is concluded that CO2 is the parameter of the carbonate system which causes both aberrant coccolithogenesis and aggregation of cells.}, keywords = {2011, Calcification, coccolithophores, morphology, ocean acidification., rcc, RCC1135}, issn = {1525-2027}, doi = {10.1029/2010GC003393}, url = {http://www.agu.org/pubs/crossref/2011/2010GC003393.shtml}, author = {Langer, Gerald and Bode, Maya} } @article {Reid2011, title = {Coccolithophores: Functional biodiversity, enzymes and bioprospecting}, journal = {Marine Drugs}, volume = {9}, number = {4}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc}, pages = {586{\textendash}602}, keywords = {2011, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.3390/md9040586}, url = {http://www.mdpi.com/1660-3397/9/4/586/}, author = {Reid, Emma L and Worthy, Charlotte A and Probert, Ian and Ali, Sohail T and Love, John and Napier, Johnathan and Littlechild, Jenny A and Somerfield, Paul J and Allen, Michael J} } @article {Jeanthon2011, title = {Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea}, journal = {Biogeosciences}, volume = {8}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, pages = {1955{\textendash}1970}, keywords = {2011, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, SBR$_\textrmP$hyto$_\textrmE$PPO, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, doi = {10.5194/bg-8-1955-2011}, author = {Jeanthon, Christian and Boeuf, Dominique and Dahan, Oc{\'e}ane and Le Gall, F and Garczarek, Laurence and Bendif, El Mahdi and Lehours, Anne-Catherine} } @article {Demir-Hilton2011, title = {Global distribution patterns of distinct clades of the photosynthetic picoeukaryote Ostreococcus}, journal = {The ISME journal}, volume = {5}, year = {2011}, note = {Publisher: International Society for Microbial Ecology tex.mendeley-tags: RCC745}, pages = {1095{\textendash}1107}, keywords = {rcc, RCC745}, doi = {10.1038/ismej.2010.209}, url = {http://dx.doi.org/10.1038/ismej.2010.209 http://www.nature.com/ismej/journal/vaop/ncurrent/suppinfo/ismej2010209s1.html http://www.nature.com/ismej/journal/v5/n7/full/ismej2010209a.html}, author = {Demir-Hilton, Elif and Sudek, Sebastian and Cuvelier, Marie L and Gentemann, Chelle L and Zehr, Jonathan P and Worden, Alexandra Z} } @article {Karpowicz2011, title = {The GreenCut2 resource, a phylogenomically derived inventory of proteins specific to the plant lineage}, journal = {Journal of Biological Chemistry}, volume = {286}, number = {24}, year = {2011}, note = {ISBN: 1083-351X (Electronic)0?021-9258 (Linking) tex.mendeley-tags: rcc745,rcc809}, month = {jun}, pages = {21427{\textendash}21439}, abstract = {The plastid is a defining structure of photosynthetic eukaryotes and houses many plant-specific processes, including the light reactions, carbon fixation, pigment synthesis, and other primary metabolic processes. Identifying proteins associated with catalytic, structural, and regulatory functions that are unique to plastid-containing organisms is necessary to fully define the scope of plant biochemistry. Here, we performed phylogenomics on 20 genomes to compile a new inventory of 597 nucleus-encoded proteins conserved in plants and green algae but not in non-photosynthetic organisms. 286 of these proteins are of known function, whereas 311 are not characterized. This inventory was validated as applicable and relevant to diverse photosynthetic eukaryotes using an additional eight genomes from distantly related plants (including Micromonas, Selaginella, and soybean). Manual curation of the known proteins in the inventory established its importance to plastid biochemistry. To predict functions for the 52\% of proteins of unknown function, we used sequence motifs, subcellular localization, co-expression analysis, and RNA abundance data. We demonstrate that 18\% of the proteins in the inventory have functions outside the plastid and/or beyond green tissues. Although 32\% of proteins in the inventory have homologs in all cyanobacteria, unexpectedly, 30\% are eukaryote-specific. Finally, 8\% of the proteins of unknown function share no similarity to any characterized protein and are plant lineage-specific. We present this annotated inventory of 597 proteins as a resource for functional analyses of plant-specific biochemistry.}, keywords = {RCC745, RCC809}, issn = {0021-9258}, doi = {10.1074/jbc.M111.233734}, url = {http://www.jbc.org/cgi/doi/10.1074/jbc.M111.233734}, author = {Karpowicz, Steven J. and Prochnik, Simon E. and Grossman, Arthur R. and Merchant, Sabeeha S.} } @article {Ota2011, title = {Gymnochlora dimorpha sp. nov., a chlorarachniophyte with unique daughter cell behaviour.}, journal = {Phycologia}, volume = {50}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc,sbr?hyto$_\textrmd$ipo}, pages = {317{\textendash}326}, keywords = {2011, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.2216/09-102.1}, author = {Ota, S and Kudo, A and Ishida, K} } @article {Luo2011, title = {Individual genome assembly from complex community short-read metagenomic datasets}, journal = {The ISME journal}, volume = {6}, year = {2011}, note = {Publisher: International Society for Microbial Ecology tex.mendeley-tags: RCC307}, pages = {898{\textendash}901}, keywords = {RCC307}, doi = {10.1038/ismej.2011.147}, url = {http://dx.doi.org/10.1038/ismej.2011.147 http://www.nature.com/ismej/journal/vaop/ncurrent/suppinfo/ismej2011147s1.html}, author = {Luo, Chengwei and Tsementzi, Despina and Kyrpides, Nikos C and Konstantinidis, Konstantinos T} } @article {Bendif2011, title = {Integrative taxonomy of the pavlovophyceae (haptophyta) : a reassessment}, journal = {Protist}, volume = {162}, year = {2011}, note = {tex.mendeley-tags: 2011,RCC1526,RCC1527,RCC1528,RCC1529,RCC1530,RCC1531,RCC1532,RCC1533,RCC1534,RCC1535,RCC1536,RCC1537,RCC1538,RCC1539,RCC1540,RCC1541,RCC1542,RCC1543,RCC1544,RCC1545,RCC1546,RCC1548,RCC1549,RCC1551,RCC1552,RCC1553,RCC1554,RCC1557,rcc,rcc1523,rcc1524,rcc1525}, pages = {738{\textendash}761}, abstract = {The Pavlovophyceae (Haptophyta) contains four genera (Pavlova, Diacronema, Exanthemachrysis and Rebecca) and only thirteen characterised species. Considering the importance of members of this class, we constructed molecular phylogenies inferred from sequencing of ribosomal gene markers with comprehensive coverage of the described diversity and using type strains when available add on culture strains. Moreover, the morphology and ultrastructure of 12 of the described species was re-examined and the pigment signatures of many culture strains were determined. The molecular analysis revealed that sequences of all described species differed, although those of Pavlova gyrans and P. pinguis were nearly identical, these potentially forming a single cryptic species complex. Four well-delineated genetic clades were identified, one of which included species of both Pavlova andDiacronema. Unique combinations of morphological/ultrastructural characters were identified foreach of these clades. The ancestral pigment signature of the Pavlovophyceae consisted of a basic set of pigments plus MV chl cPAV, the latter being entirely absent in the Pavlova + Diacronema clade and supplemented by DV chl cPAV in part of the Exanthemachrysis clade. Based on this combination of characters, we propose a taxonomic revision of the class, with transfer of several Pavlova species to an emended Diacronema genus. The evolution of the class is discussed in the context of the phylogenetic reconstruction presented.}, keywords = {2011, ASSEMBLE, rcc, RCC1523, rcc1524, rcc1525, RCC1526, RCC1527, RCC1528, RCC1529, RCC1530, RCC1531, RCC1532, RCC1533, RCC1534, RCC1535, RCC1536, RCC1537, RCC1538, RCC1539, RCC1540, RCC1541, RCC1542, RCC1543, RCC1544, RCC1545, RCC1546, RCC1548, RCC1549, RCC1551, RCC1552, RCC1553, RCC1554, RCC1557, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.1016/j.protis.2011.05.001}, author = {Bendif, E M and Probert, I and Herv{\'e}, A and Billard, C and Goux, D and Lelong, C and Cadoret, J P and V{\'e}ron, B} } @article {Blot2011, title = {Light history influences the response of the marine cyanobacterium Synechococcus sp. WH7803 to oxidative stress}, journal = {Plant Physiology}, volume = {156}, year = {2011}, note = {ISBN: 1532-2548 (Electronic) 0032-0889 (Linking) tex.mendeley-tags: 2011,rcc,sbr?hyto?app}, pages = {1934{\textendash}1954}, abstract = {Marine Synechococcus undergo a wide range of environmental stressors, especially high and variable irradiance, which may induce oxidative stress through the generation of reactive oxygen species (ROS). While light and ROS could act synergistically on the impairment of photosynthesis, inducing photodamage and inhibiting photosystem II repair, acclimation to high irradiance is also thought to confer resistance to other stressors. To identify the respective roles of light and ROS in the photoinhibition process and detect a possible light-driven tolerance to oxidative stress, we compared the photophysiological and transcriptomic responses of Synechococcus sp. WH7803 acclimated to low (LL) or high light (HL) to oxidative stress, induced by hydrogen peroxide (H2O2) or methylviologen. While photosynthetic activity was much more affected in HL than in LL cells, only HL cells were able to recover growth and photosynthesis after addition of 25 microM H2O2. Depending upon light conditions and H2O2 concentration, the latter oxidizing agent induced photosystem II inactivation through both direct damages to the reaction centres and inhibition of its repair cycle. Although the global transcriptome response appeared similar in LL and HL cells, some processes were specifically induced in HL cells that seemingly helped them withstand oxidative stress, including enhancement of photoprotection and ROS detoxification, repair of ROS-driven damages and regulation of redox state. Detection of putative LexA binding sites allowed the identification of the putative LexA regulon, which was down-regulated in HL compared to LL cells, but up-regulated by oxidative stress under both growth irradiances.}, keywords = {2011, rcc, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto?app}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=21670225}, author = {Blot, N and Mella-Flores, D and Six, C and Lecorguille, G and Boutte, C and Peyrat, A and Monnier, A and Ratin, M and Gourvil, P and Campbell, D A and Garczarek, L} } @article {Hagino2011, title = {New evidence for morphological and genetic variation in the cosmopolitan coccolithophore Emiliana huxleyi (prymnesiophyceae) from the cox1b-ATP4 genes}, journal = {Journal of Phycology}, volume = {47}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc,sbr?hyto?ppo}, pages = {1164{\textendash}1176}, abstract = {Emiliania huxleyi (Lohmann) Hay et Mohler is a cosmopolitan coccolithophore occurring from tropical to subpolar waters and exhibiting variations in morphology of coccoliths possibly related to environmental conditions. We examined morphological characters of coccoliths and partial mitochondrial sequences of the cytochrome oxidase 1b (cox1b) through adenosine triphosphate synthase 4 (atp4) genes of thirty-nine clonal E. huxleyi strains from the Atlantic and Pacific Oceans, Mediterranean Sea and their adjacent seas. Based on the morphological study of culture strains by SEM, Type O, a new morphotype characterized by coccoliths with an open central area, was separated from existing morphotypes A, B, B/C, C, R and var. corona, characterized by coccoliths with central area elements. Molecular phylogenetic studies revealed that E. huxleyi consists of at least two mitochondrial sequence groups with different temperature preferences/tolerances: a cool water group occurring in subarctic North Atlantic and Pacific and a warm water group occurring in the sub-tropical Atlantic and Pacific and in the Mediterranean Sea.}, keywords = {2011, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1111/j.1529-8817.2011.01053.x}, author = {Hagino, K and Bendif, El Mahdi and Young, J and Kogame, K and Takano, Y and Probert, I and Horiguchi, T and de Vargas, C and Okada, H} } @article {Gobler2011, title = {Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, number = {11}, year = {2011}, note = {ISBN: 0027-8424 tex.mendeley-tags: RCC,rcc}, pages = {4352{\textendash}4357}, abstract = {Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking, because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements showed that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the genome of A. anophagefferens and compared its gene complement with those of six competing phytoplankton species identified through metaproteomics. Using an ecogenomic approach, we specifically focused on gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 Mbp) and has more genes involved in light harvesting, organic carbon and nitrogen use, and encoding selenium-and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species, with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus, has facilitated the proliferation of this and potentially other HABs.}, keywords = {brown-tide blooms, comparative genomics, eutrophication, evolution, genome, genomics, long-island, marine-phytoplankton, multidrug, proteins, proteome, rcc, repeat, responses, san-francisco bay, signal-transduction, transporters}, doi = {10.1073/pnas.1016106108}, author = {Gobler, C J and Berry, D L and Dyhrman, S T and Wilhelm, S W and Salamov, A and Lobanov, A V and Zhang, Y and Collier, J L and Wurch, L L and Kustka, A B and Dill, B D and Shah, M and VerBerkmoes, N C and Kuo, A and Terry, A and Pangilinan, J and Lindquist, E A and Lucas, S and Paulsen, I T and Hattenrath-Lehmann, T K and Talmage, S C and Walker, E A and Koch, F and Burson, A M and Marcoval, M A and Tang, Y Z and LeCleir, G R and Coyne, K J and Berg, G M and Bertrand, E M and Saito, M A and Gladyshev, V N and Grigoriev, I V} } @article {Ishida2011, title = {Partenskyella glossopodia (Chlorarachniophyceae) possesses a nucleomorph genome of approximately 1 Mbp}, journal = {Phycological Research}, volume = {59}, number = {2}, year = {2011}, note = {Publisher: Blackwell Publishing Asia tex.mendeley-tags: RCC,rcc}, pages = {120{\textendash}122}, abstract = {SUMMARY The nucleomorph genome size of the recently described chlorarachniophyte Partenskyella glossopodia, which forms an independent lineage in the phylogeny of chlorarachniophytes, was analyzed by pulse-field gel electrophoresis and Southern hybridization. These analyses showed that the nucleomorph genome of P. glossopodia is composed of three linear chromosomes that are about 445 kbp, 313 kbp, and 275 kbp in size. Thus, the total genome size is approximately 1033 kbp, which is significantly larger than the known size of chlorarachniophyte nucleomorph genomes, i.e. 330{\textendash}610 kbp. This is the first study to report a nucleomorph genome that reaches approximately 1 Mbp in size.}, keywords = {Chlorarachniophytes, genome reduction, genome size, nucleomorph, Partenskyella glossopodia, rcc}, doi = {10.1111/j.1440-1835.2011.00608.x}, url = {http://dx.doi.org/10.1111/j.1440-1835.2011.00608.x}, author = {Ishida, Ken-ichiro and Endo, Hiroko and Koike, Sayaka} } @article {Laviale2011, title = {Relationships between pigment ratios and growth irradiance in 11 marine phytoplankton species}, journal = {Marine Ecology Progress Series}, volume = {425}, year = {2011}, note = {tex.mendeley-tags: rcc}, month = {mar}, pages = {63{\textendash}77}, keywords = {cultures, hplc, irradiance, of the publisher, permitted without written consent, phytoplankton, pigment ratios, rcc, RCC?o?dd, regression analysis}, issn = {0171-8630}, doi = {10.3354/meps09013}, url = {http://www.int-res.com/abstracts/meps/v425/p63-77/}, author = {Laviale, M and Neveux, J} } @article {Edvardsen2011, title = {Ribosomal DNA phylogenies and a morphological revision privide the basis for a new taxonomy of Prymnesiales (Haptophyta)}, journal = {European Journal of Phycology}, volume = {46}, year = {2011}, note = {tex.mendeley-tags: 2011,RCC1185,RCC1187,RCC1189,RCC1385,RCC1387,RCC1388,RCC1390,RCC1432,RCC1438,RCC1440,RCC1441,RCC1448,RCC1453,RCC2056,RCC2057,RCC2059,RCC2060,RCC2061,RCC2063,RCC2064,RCC305,RCC339,RCC3417,RCC3421,RCC3422,RCC3424,RCC3425,RCC3429,RCC406,rcc}, pages = {202{\textendash}228}, keywords = {2011, ASSEMBLE, rcc, RCC1185, RCC1187, RCC1189, RCC1385, RCC1387, RCC1388, RCC1390, RCC1432, RCC1438, RCC1440, RCC1441, RCC1448, RCC1453, RCC2056, RCC2057, RCC2059, RCC2060, RCC2061, RCC2063, RCC2064, RCC305, RCC339, RCC3417, RCC3421, RCC3422, RCC3424, RCC3425, RCC3429, RCC406, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.1080/09670262.2011.594095}, author = {Edvardsen, B and Eikrem, W and Throndsen, J and A., Saez and Probert, I and Medlin, L} } @article {Beaufort2011, title = {Sensitivity of coccolithophores to carbonate chemistry and ocean acidification}, journal = {Nature}, volume = {476}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc,sbr?hyto?ppo}, pages = {80{\textendash}83}, abstract = {Coccolithophores produce the major fraction of pelagic carbonate, a key component of the carbon cycle. The effect of elevated CO2 on their calcification is poorly understood. Culture experiments have yielded varied calcification responses to increased pCO2 between and within coccolithophore taxa. We used a novel automated method for pattern recognition and morphometric analysis to quantify the calcite mass of coccolithophores from {\textquestiondown}700 samples from present past (last 40-Kyr) oceans. Comparison of morphological data with ocean carbonate chemistry reconstructed in both space and time indicate decreasing calcification with increasing pCO2, and decreasing CO32. At pH {\textexclamdown}8.0, delicate Emiliania huxleyi are strongly affected by decalcification. However, highly calcified E. huxleyi morphotypes predominate in waters with lowest pH. This suggests that coccolithophore strains pre-adapted to future, more acidic oceans already populate regions of contemporary oceans. The future carbon feedback from coccolithophore calcification will depend on the genetic diversity and adaptability of coccolithophore populations.}, keywords = {2011, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1038/nature10295}, author = {Beaufort, L and Probert, I and de Garidel-Thoron, T and Bendif, E M and Ruiz-Pino, D and Metzl, N and Goyet, C and Buchet, N and Coupel, P and Grelaud, M and Rost, B and Rickaby, R E M and de Vargas, C} } @article {Rokitta2011, title = {Transcriptome analyses reveal differential gene expression patterns between the life-cycle stages of Emiliania huxleyi (Haptophyta) and reflect specialization to different ecological niches}, journal = {Journal of Phycology}, volume = {47}, number = {4}, year = {2011}, note = {Publisher: Blackwell Publishing Ltd tex.mendeley-tags: 2011,rcc,sbr?hyto?ppo}, pages = {829{\textendash}838}, abstract = {Coccolithophores, especially the abundant, cosmopolitan species Emiliania huxleyi (Lohmann) W. W. Hay et H. P. Mohler, are one of the main driving forces of the oceanic carbonate pump and contribute significantly to global carbon cycling, due to their ability to calcify. A recent study indicates that termination of diploid blooms by viral infection induces life-cycle transition, and speculation has arisen about the role of the haploid, noncalcifying stage in coccolithophore ecology. To explore gene expression patterns in both life-cycle stages, haploid and diploid cells of E. huxleyi (RCC 1217 and RCC 1216) were acclimated to limiting and saturating photon flux densities. Transcriptome analyses were performed to assess differential genomic expression related to different ploidy levels and acclimation light intensities. Analyses indicated that life-cycle stages exhibit different properties of regulating genome expression (e.g., pronounced gene activation and gene silencing in the diploid stage), proteome maintenance (e.g., increased turnover of proteins in the haploid stage), as well as metabolic processing (e.g., pronounced primary metabolism and motility in the haploid stage and calcification in the diploid stage). Furthermore, higher abundances of transcripts related to endocytotic and digestive machinery were observed in the diploid stage. A qualitative feeding experiment indicated that both life-cycle stages are capable of particle uptake (0.5 ??m diameter) in late-stationary growth phase. Results showed that the two life-cycle stages represent functionally distinct entities that are evolutionarily shaped to thrive in the environment they typically inhabit.}, keywords = {2011, endocytosis, Life-cycle stages, microarray, quantitative RT-PCR, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo, transcriptome profiling}, doi = {10.1111/j.1529-8817.2011.01014.x}, url = {http://dx.doi.org/10.1111/j.1529-8817.2011.01014.x}, author = {Rokitta, Sebastian D and de Nooijer, Lennart J and Trimborn, Scarlett and de Vargas, Colomban and Rost, Bj{\"o}rn and John, Uwe} } @article {Lepere2011, title = {Whole Genome Amplification (WGA) of marine photosynthetic eukaryote populations}, journal = {FEMS Microbiology Ecology}, volume = {76}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?ppo}, pages = {516{\textendash}523}, keywords = {2011, PICOFUNPAC, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto$_\textrmd$ipo, sbr?hyto?ppo}, doi = {10.1111/j.1574-6941.2011.01072.x}, author = {Lepere, Cecile and Demura, M and Kawachi, M and Romac, S and Probert, I and Vaulot, D} } @article {Foresi2010, title = {Characterization of a nitric oxide synthase from the plant kingdom: NO generation from the green alga Ostreococcus tauri is light irradiance and growth phase dependent}, journal = {The Plant Cell}, volume = {22}, number = {11}, year = {2010}, note = {Edition: 2010/12/02 ISBN: 1532-298X (Electronic) 1040-4651 (Linking) tex.mendeley-tags: RCC745}, pages = {3816{\textendash}3830}, abstract = {The search for a nitric oxide synthase (NOS) sequence in the plant kingdom yielded two sequences from the recently published genomes of two green algae species of the Ostreococcus genus, O. tauri and O. lucimarinus. In this study, we characterized the sequence, protein structure, phylogeny, biochemistry, and expression of NOS from O. tauri. The amino acid sequence of O. tauri NOS was found to be 45\% similar to that of human NOS. Folding assignment methods showed that O. tauri NOS can fold as the human endothelial NOS isoform. Phylogenetic analysis revealed that O. tauri NOS clusters together with putative NOS sequences of a Synechoccocus sp strain and Physarum polycephalum. This cluster appears as an outgroup of NOS representatives from metazoa. Purified recombinant O. tauri NOS has a K(m) for the substrate l-Arg of 12 +/- 5 muM. Escherichia coli cells expressing recombinant O. tauri NOS have increased levels of NO and cell viability. O. tauri cultures in the exponential growth phase produce 3-fold more NOS-dependent NO than do those in the stationary phase. In O. tauri, NO production increases in high intensity light irradiation and upon addition of l-Arg, suggesting a link between NOS activity and microalgal physiology.}, keywords = {*Light, Amino Acid Sequence, Animals, Base Sequence, Chlorophyta/*enzymology/*growth \& development/phys, Humans, Isoenzymes/chemistry/genetics/metabolism, Models, Molecular, Molecular Sequence Data, Nitric Oxide Synthase/chemistry/genetics/*metaboli, Nitric Oxide/*biosynthesis, phylogeny, Plant Proteins/genetics/*metabolism, Protein Structure, rcc, RCC745, Sequence Alignment, Tertiary}, doi = {10.1105/tpc.109.073510}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=21119059}, author = {Foresi, N and Correa-Aragunde, N and Parisi, G and Calo, G and Salerno, G and Lamattina, L} } @article {Turmel2010, title = {A deviant genetic code in the reduced mitochondrial genome of the picoplanktonic green alga pycnococcus provasolii}, journal = {Journal of Molecular Evolution}, volume = {70}, number = {2}, year = {2010}, note = {ISBN: 0022-2844 tex.mendeley-tags: RCC299}, pages = {203{\textendash}214}, abstract = {Reduction in size of flagellated chlorophytes occurred multiple times during evolution, providing the opportunity to study the consequences of cell reduction on genome architecture. Recent investigations on the chloroplast genomes of the tiny prasinophyceans Ostreococcus tauri (Mamiellales), Micromonas sp. RCC299 (Mamiellales), and Pycnococcus provasolii (Pseudocourfieldiales) highlighted their extreme compaction and reduced gene repertoires. Genome compaction is also exemplified by the Ostreococcus and Micromonas mitochondrial DNAs (mtDNAs) although they have retained almost all of the about 65 genes presumably present in the mitochondria of ancestral prasinophyceans. In this study, the mitochondrial genome of Pycnococcus was sequenced and compared to those of previously examined chlorophytes. Our results document the first case where cellular reduction of a free-living alga was accompanied by marked reduction in gene content of both the mitochondrial and chloroplast genomes. At 24,321 bp, the intronless Pycnococcus mitochondrial genome falls within the lower size range displayed by green algal mtDNAs. The 36 conserved genes, specifying two rRNAs with conventional structures, 16 tRNAs and 18 proteins, are all encoded on the same DNA strand and represent 88\% of the genome. Besides a pronounced codon bias, the protein-coding genes feature a variant genetic code characterized by the use of TGA (normally a stop codon) to code for tryptophan, and the unprecedented use of TTA and TTG (normally leucine codons) as stop codons. We conclude that substantial reduction of the mitochondrial genome occurred in at least three independent chlorophyte lineages and that this process entailed a number of convergent changes in these lineages.}, keywords = {RCC299}, doi = {10.1007/s00239-010-9322-6}, author = {Turmel, Monique and Otis, Christian and Lemieux, Claude} } @article {Franklin2010, title = {Dimethylsulphoniopropionate (DMSP), DMSP-lyase activity (DLA) and dimethylsulphide (DMS) in 10 species of coccolithophore}, journal = {Marine Ecology-Progress Series}, volume = {410}, year = {2010}, note = {ISBN: 0171-8630 tex.mendeley-tags: 2010,rcc}, pages = {13{\textendash}23}, abstract = {We investigated dimethylsulphoniopropionate (DMSP) quota (pg DMSP cell(-1)), intracellular DMSP concentration (mM), in vitro and in vivo DMSP-lyase activity (DLA) and dimethylsulphide (DMS) concentration in batch cultures of 10 species of coccolithophore. Species were chosen to span the phylogenetic and size range that exists within the coccolithophores. Our overall objective was to examine if Emiliania huxleyi, considered a {\textquoteright}model{\textquoteright} coccolithophore species, is representative in terms of DMSP, DLA and DMS, because other coccolithophores contribute substantially to phyto-plankton biomass and carbon fluxes in temperate and tropical waters. DMSP was found in all species, and DMSP quotas correlated significantly with cell volume, reflecting the fundamental physiological role of DMSP as a compatible solute in this group. This DMSP quota-cell volume relationship can be used to calculate the relative contribution of different species to total DMSP. Lowered nutrient availability (batch growth at a 10-fold lower nutrient concentration) did not significantly affect DMSP quota. In contrast to DMSP, DLA and DMS concentration were variable between the subset of species investigated. Coccolithophore DLA is known only in E. huxleyi and Gephyrocapsa oceanica, and we found DLA to be restricted to these closely related species. If DLA is restricted to a subset of coccolithophores, then those species are more likely to emit DMS directly in the sea. Our results indicate that in ecosystems where coccolithophores form stable populations, species other than E. huxleyi can make significant contributions to the particulate DMSP pool and hence to the amount of DMSP potentially available to the microbial loop.}, keywords = {2010, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.3354/meps08596}, author = {Franklin, D J and Steinke, M and Young, J and Probert, I and Malin, G} } @article {gile_dna_2010, title = {Dna Barcoding of Chlorarachniophytes Using Nucleomorph Its Sequences1}, journal = {Journal of Phycology}, volume = {46}, number = {4}, year = {2010}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1529-8817.2010.00851.x}, pages = {743{\textendash}750}, abstract = {Chlorarachniophytes are a small group of marine photosynthetic protists. They are best known as examples of an intermediate stage of secondary endosymbiosis: their plastids are derived from green algae and retain a highly reduced nucleus, called a nucleomorph, between the inner and outer pairs of membranes. Chlorarachniophytes can be challenging to identify to the species level, due to their small size, complex life cycles, and the fact that even genus-level diagnostic morphological characters are observable only by EM. Few species have been formally described, and many available culture collection strains remain unnamed. To alleviate this difficulty, we have developed a barcoding system for rapid and accurate identification of chlorarachniophyte species in culture, based on the internal transcribed spacer (ITS) region of the nucleomorph rRNA cistron. Although this is a multicopy locus, encoded in both subtelomeric regions of each chromosome, interlocus variability is low due to gene conversion by homologous recombination in this region. Here, we present barcode sequences for 39 cultured strains of chlorarachniophytes (>80\% of currently available strains). Based on barcode data, other published molecular data, and information from culture records, we were able to recommend names for 21 out of the 24 unidentified, partially identified, or misidentified chlorarachniophyte strains in culture. Most strains could be assigned to previously described species, but at least two to as many as five new species may be present among cultured strains.}, keywords = {Bigelowiella, Chlorarachnion, culture collections, Gymnochlora, internal transcribed spacer, Lotharella, Norrisiella, Partenskyella, RCC337, RCC375, RCC376, RCC435, RCC530, RCC531, RCC623, RCC626}, issn = {1529-8817}, doi = {10.1111/j.1529-8817.2010.00851.x}, url = {http://onlinelibrary.wiley.com/doi/abs/10.1111/j.1529-8817.2010.00851.x}, author = {Gile, Gillian H. and Stern, Rowena F. and James, Erick R. and Keeling, Patrick J.} } @article {Frada2010, title = {A guide to extant coccolithophores (Calcihaptophycidae, Haptophyta) using light microscopy.}, journal = {Journal of Nannoplankton Research}, volume = {31}, year = {2010}, note = {tex.mendeley-tags: 2010,rcc,sbr?hyto?ppo}, pages = {58{\textendash}112}, keywords = {2010, ? No DOI found, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, author = {Frada, Miguel and Young, Jeremy and Cach{\~a}o, M{\'a}rio and Lino, S{\'\i}lvia and Martins, Ana and Narciso, {\'A}urea and Probert, Ian and de Vargas, Colomban} } @article {Moreau2010, title = {Marine Prasinovirus genomes show low evolutionary divergence and acquisition of protein metabolism genes by horizontal gene transfer}, journal = {Journal of Virology}, volume = {84}, number = {24}, year = {2010}, note = {ISBN: 0022-538X tex.mendeley-tags: RCC1105,RCC745}, pages = {12555{\textendash}12563}, abstract = {Although marine picophytoplankton are at the base of the global food chain, accounting for half of the planetary primary production, they are outnumbered 10 to 1 and are largely controlled by hugely diverse populations of viruses. Eukaryotic microalgae form a ubiquitous and particularly dynamic fraction of such plankton, with environmental clone libraries from coastal regions sometimes being dominated by one or more of the three genera Bathycoccus, Micromonas, and Ostreococcus (class Prasinophyceae). The complete sequences of two double-stranded (dsDNA) Bathycoccus, one dsDNA Micromonas, and one new dsDNA Ostreococcus virus genomes are described. Genome comparison of these giant viruses revealed a high degree of conservation, both for orthologous genes and for synteny, except for one 36-kb inversion in the Ostreococcus lucimarinus virus and two very large predicted proteins in Bathycoccus prasinos viruses. These viruses encode a gene repertoire of certain amino acid biosynthesis pathways never previously observed in viruses that are likely to have been acquired from lateral gene transfer from their host or from bacteria. Pairwise comparisons of whole genomes using all coding sequences with homologous counterparts, either between viruses or between their corresponding hosts, revealed that the evolutionary divergences between viruses are lower than those between their hosts, suggesting either multiple recent host transfers or lower viral evolution rates.}, keywords = {RCC1105, RCC745}, doi = {10.1128/jvi.01123-10}, author = {Moreau, Herv{\'e} and Piganeau, Gwenael and Desdevises, Yves and Cooke, Richard and Derelle, Evelyne and Grimsley, Nigel} } @article {McDonald2010, title = {The mixed lineage nature of nitrogen transport and assimilation in marine eukaryotic phytoplankton: a case study of Micromonas}, journal = {Molecular Biology and Evolution}, volume = {27}, number = {10}, year = {2010}, note = {tex.mendeley-tags: RCC299}, pages = {2268{\textendash}2283}, abstract = {The prasinophyte order Mamiellales contains several widespread marine picophytoplankton (<=2 ??m diameter) taxa, including Micromonas and Ostreococcus. Complete genome sequences are available for two Micromonas isolates, CCMP1545 and RCC299. We performed in silico analyses of nitrogen transporters and related assimilation genes in CCMP1545 and RCC299 and compared these with other green lineage organisms as well as Chromalveolata, fungi, bacteria, and archaea. Phylogenetic reconstructions of ammonium transporter (AMT) genes revealed divergent types contained within each Mamiellales genome. Some were affiliated with plant and green algal AMT1 genes and others with bacterial AMT2 genes. Land plant AMT2 genes were phylogenetically closer to archaeal transporters than to Mamiellales AMT2 genes. The Mamiellales represent the first green algal genomes to harbor AMT2 genes, which are not found in Chlorella and Chlamydomonas or the chromalveolate algae analyzed but are present in oomycetes. Fewer nitrate transporter (NRT) than AMT genes were identified in the Mamiellales. NRT1 was found in all but CCMP1545 and showed highest similarity to Mamiellales and proteobacterial NRTs. NRT2 genes formed a bootstrap-supported clade basal to other green lineage organisms. Several nitrogen-related genes were colocated, forming a nitrogen gene cluster. Overall, RCC299 showed the most divergent suite of nitrogen transporters within the various Mamiellales genomes, and we developed TaqMan quantitative polymerase chain reaction primer{\textendash}probes targeting a subset of these, as well as housekeeping genes, in RCC299. All those investigated showed expression either under standard growth conditions or under nitrogen depletion. Like other recent publications, our findings show a higher degree of {\textquotedblleft}mixed lineage gene affiliations{\textquotedblright} among eukaryotes than anticipated, and even the most phylogenetically anomalous versions appear to be functional. Nitrogen is often considered a regulating factor for phytoplankton populations. This study provides a springboard for exploring the use and functional diversification of inorganic nitrogen transporters and related genes in eukaryotic phytoplankton.}, keywords = {rcc, RCC299}, doi = {10.1093/molbev/msq113}, url = {http://mbe.oxfordjournals.org/content/27/10/2268.abstract}, author = {McDonald, Sarah M and Plant, Joshua N and Worden, Alexandra Z} } @article {Marin2010, title = {Molecular phylogeny and classification of the Mamiellophyceae class. nov. (Chlorophyta) based on sequence comparisons of the nuclear- and plastid-encoded rRNA operons}, journal = {Protist}, volume = {161}, number = {2}, year = {2010}, note = {ISBN: 1618-0941 tex.mendeley-tags: Micromonas,rcc}, pages = {304{\textendash}336}, abstract = {Molecular phylogenetic analyses of the Mamiellophyceae classis nova, a ubiquitous group of largely picoplanktonic green algae comprising scaly and non-scaly prasinophyte unicells, were performed using single and concatenated gene sequence comparisons of the nuclear- and plastid-encoded rRNA operons. The study resolved all major clades within the class, identified molecular signature sequences for most clades through an exhaustive search for non-homoplasious synapomorphies [Marin et al. (2003): Protist 154: 99-145] and incorporated these signatures into the diagnoses of two novel orders, Monomastigales ord nov., Dolichomastigales ord. nov., and four novel families, Monomastigaceae fam. nov., Dolichomastigaceae fam. nov., Crustomastigaceae fam. nov., and Bathycoccaceae fam. nov., within a revised classification of the class. A database search for the presence of environmental rDNA sequences in the Monomastigales and Dolichomastigales identified an unexpectedly large genetic diversity of Monomastigales confined to freshwater, a novel clade (Dolicho$_\textrmB$) in the Dolichomastigaceae from deep sea sediments and a novel freshwater clade in the Crustomastigaceae. The Mamiellophyceae represent one of the ecologically most successful groups of eukaryotic, photosynthetic picoplankters in marine and likely also freshwater environments. Copyright 2009 Elsevier GmbH. All rights reserved.}, keywords = {Index Medicus, Micromonas, rcc}, doi = {10.1016/j.protis.2009.10.002}, author = {Marin, Birger and Melkonian, Michael} } @article {Mohr2010, title = {A new chlorophyll d -containing cyanobacterium : evidence for niche adaptation in the genus Acaryochloris}, journal = {The ISME journal}, year = {2010}, note = {tex.mendeley-tags: RCC,RCC1983,rcc}, pages = {1456{\textendash}1469}, abstract = {Chlorophyll d is a photosynthetic pigment that, based on chemical analyses, has only recently been recognized to be widespread in oceanic and lacustrine environments. However, the diversity of organisms harbouring this pigment is not known. Until now, the unicellular cyanobacterium Acaryochloris marina is the only characterized organism that uses chlorophyll d as a major photopigment. In this study we describe a new cyanobacterium possessing a high amount of chlorophyll d, which was isolated from waters around Heron Island, Great Barrier Reef (231 260 31.200 S, 1511 540 50.400 E). The 16S ribosomal RNA is 2\% divergent from the two previously described isolates of A. marina, which were isolated from waters around the Palau islands (Pacific Ocean) and the Salton Sea lake (California), suggesting that it belongs to a different clade within the genus Acaryochloris. An overview sequence analysis of its genome based on Illumina technology yielded 871 contigs with an accumulated length of 8 371965nt. Their analysis revealed typical features associated with Acaryochloris, such as an extended gene family for chlorophyll-binding proteins. However, compared with A. marina MBIC11017, distinct genetic, morphological and physiological differences were observed. Light saturation is reached at lower light intensities, Chl d/a ratios are less variable with light intensity and the phycobiliprotein phycocyanin is lacking, suggesting that cyanobacteria of the genus Acaryochloris occur in distinct ecotypes. These data characterize Acaryochloris as a niche-adapted cyanobacterium and show that more rigorous attempts are worthwhile to isolate, cultivate and analyse chlorophyll d-containing cyanobacteria for understanding the ecophysiology of these organisms. The}, keywords = {acaryochloris, chlorophyll d, coral reef, cyanobacteria, microbial diversity, overview, rcc, RCC1983}, doi = {10.1038/ismej.2010.67}, author = {Mohr, Remus and Schliep, Martin and Kurz, Thorsten and Maldener, Iris and Adams, David G and Larkum, Anthony D W and Chen, Min and Hess, Wolfgang R} } @article {Siano2010, title = {Pelagodinium gen. nov. and P. beii comb. nov., a dinoflagellate symbiont of planktonic foraminifera}, journal = {Protist}, volume = {161}, year = {2010}, note = {tex.mendeley-tags: 2010,rcc,rcc1491,sbr?hyto?ppo}, pages = {385{\textendash}399}, abstract = {The taxonomic status of the free-living stage of the dinoflagellate Gymnodinium b{\'e}ii, symbiont of the foraminifer Orbulina universa, was reassessed on the basis of detailed morpho-genetic analyses. Electron microscopy observations revealed previously undescribed morphological features of the cell that are important for species recognition. The presence of a single elongated apical vesicle (EAV) ornamented with a row of small knobs, absent in species of the genus Gymnodinium, calls into question the current taxonomic position of the symbiont. The presence of a type E extraplastidial eyespot, the arrangement of the amphiesmal vesicles in series and the absence of trichocysts confirm the affiliation with other symbiotic dinoflagellates and certain genetically related non-symbiotic genera, all belonging to the order Suessiales. The arrangement of the series of vesicles of the analyzed strain is unique within the Suessiales, and the ultrastructure of the pyrenoid is different from other symbiotic dinoflagellates. A large subunit (LSU) rDNA phylogenetic analysis confirmed that the analyzed pelagic symbiont clusters in an independent, well-supported clade within the Suessiales with other sequences of symbiotic dinoflagellates extracted from planktonic foraminifera. Hence a novel genus, Pelagodinium gen. nov., is erected for this pelagic, symbiotic dinoflagellate, and Gymnodinium b{\'e}ii is reclassified as Pelagodinium b{\'e}ii.}, keywords = {2010, ASSEMBLE, rcc, rcc1491, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1016/j.protis.2010.01.002}, author = {Siano, R and Montresor, M and Probert, I and Not, F and de Vargas, C} } @article {Minge2010, title = {A phylogenetic mosaic plastid proteome and unusual plastid-targeting signals in the green-colored dinoflagellate Lepidodinium chlorophorum}, journal = {BMC Evolutionary Biology}, volume = {10}, year = {2010}, note = {ISBN: 1471-2148 tex.mendeley-tags: 2010,rcc}, pages = {191}, abstract = {Background: Plastid replacements through secondary endosymbioses include massive transfer of genes from the endosymbiont to the host nucleus and require a new targeting system to enable transport of the plastid-targeted proteins across 3-4 plastid membranes. The dinoflagellates are the only eukaryotic lineage that has been shown to have undergone several plastid replacement events, and this group is thus highly relevant for studying the processes involved in plastid evolution. In this study, we analyzed the phylogenetic origin and N-terminal extensions of plastid-targeted proteins from Lepidodinium chlorophorum, a member of the only dinoflagellate genus that harbors a green secondary plastid rather than the red algal-derived, peridinin-containing plastid usually found in photosynthetic dinoflagellates. Results: We sequenced 4,746 randomly picked clones from a L. chlorophorum cDNA library. 22 of the assembled genes were identified as genes encoding proteins functioning in plastids. Some of these were of green algal origin. This confirms that genes have been transferred from the plastid to the host nucleus of L. chlorophorum and indicates that the plastid is fully integrated as an organelle in the host. Other nuclear-encoded plastid-targeted protein genes, however, are clearly not of green algal origin, but have been derived from a number of different algal groups, including dinoflagellates, streptophytes, heterokonts, and red algae. The characteristics of N-terminal plastid-targeting peptides of all of these genes are substantially different from those found in peridinin-containing dinoflagellates and green algae. Conclusions: L. chlorophorum expresses plastid-targeted proteins with a range of different origins, which probably arose through endosymbiotic gene transfer (EGT) and horizontal gene transfer (HGT). The N-terminal extension of the genes is different from the extensions found in green alga and other dinoflagellates (peridinin- and haptophyte plastids). These modifications have likely enabled the mosaic proteome of L. chlorophorum.}, keywords = {2010, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.1186/1471-2148-10-191}, author = {Minge, M A and Shalchian-Tabrizi, K and Torresen, O K and Takishita, K and Probert, I and Inagaki, Y and Klaveness, D and Jakobsen, K S} } @article {Jardillier2010, title = {Significant CO2 fixation by small prymnesiophytes in the subtropical and tropical northeast Atlantic Ocean}, journal = {The ISME Journal}, volume = {4}, year = {2010}, note = {Publisher: International Society for Microbial Ecology tex.mendeley-tags: Micromonas,rcc}, pages = {1180{\textendash}1192}, keywords = {Micromonas, rcc}, doi = {10.1038/ismej.2010.36}, url = {http://dx.doi.org/10.1038/ismej.2010.36 http://www.nature.com/ismej/journal/vaop/ncurrent/suppinfo/ismej201036s1.html}, author = {Jardillier, Ludwig and Zubkov, Mikhail V and Pearman, John and Scanlan, David J} } @article {Liu2010, title = {A timeline of the environmental genetics of the haptophytes}, journal = {Molecular Biology and Evolution}, volume = {27}, year = {2010}, note = {tex.mendeley-tags: 2010,rcc,sbr?hyto?ppo}, pages = {171{\textendash}176}, abstract = {The use of genomic data and the rise of phylogenomics have radically changed our view of the eukaryotic tree of life at a high taxonomic level by identifying four to six "supergroups". Yet our understanding of the evolution of key innovations within each of these supergroups is limited because of poor species sampling relative to the massive diversity encompassed by each supergroup. Here we apply a multigene approach that incorporates a wide taxonomic diversity to infer the timeline of the emergence of strategic evolutionary transitions in the haptophytes, a group of ecologically and biogeochemically significant marine protists that belong to the Chromalveolata supergroup. Four genes (SSU, LSU, tufA and rbcL) were extensively analyzed under several Bayesian models to assess the robustness of the phylogeny, particularly with respect to (i) data partitioning, (ii) the origin of the genes (host vs. endosymbiont), (iii) across-site rate variation and (iv) across-lineage rate variation. We show with a relaxed clock analysis that the origin of haptophytes dates back to 824 MYA (95\% highest probability density 1031-637 MYA). Our dating results show that the ability to calcify evolved earlier than previously thought, between 329-291 MYA, in the Carboniferous period, and that the transition from mixotrophy to autotrophy occurred during the same time period. Although these two transitions precede a habitat change of major diversities from coastal / neritic waters to the pelagic realm (291-243 MYA, around the P/Tr boundary event), the emergence of calcification, full autotrophy and oceanic lifestyle seem mutually independent.}, keywords = {2010, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1093/molbev/msp222}, url = {http://mbe.oxfordjournals.org/cgi/content/abstract/msp222v1}, author = {Liu, Hui and Aris-Brosou, Stephane and Probert, Ian and de Vargas, Colomban} } @conference {Meusnier2009, title = {DNA barcoding of protists in culture collections}, booktitle = {Third international barcode of life conference}, year = {2009}, note = {tex.mendeley-tags: RCC,rcc}, address = {Mexico City}, keywords = {? No DOI found, rcc, SBR$_\textrmP$hyto$_\textrmD$PO}, author = {Meusnier, Isabelle and Andersen, Robert A and Stern, Rowena and Bertrand, C and Kuepper, Frithjof and Brand, Jerry and Friedl, Thomas and Blackburn, Susan and Dinh, Donna and Acreman, Judy and Sedl{\'a}{\v c}ek, Ivo and P{\v r}ibyl, Pavel and Jutson, Maria and Phang, Siew Moi and Melkonian, M and Karpov, S and Hajibabaei, Mehrdad} } @article {Scanlan2009, title = {Ecological genomics of marine picocyanobacteria}, journal = {Microbiology and Molecular Biology Reviews}, volume = {73}, year = {2009}, note = {tex.mendeley-tags: 2009,rcc,sbr?hyto?app}, pages = {249{\textendash}299}, keywords = {2009, rcc, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto?app}, doi = {10.1128/MMBR.00035-08}, author = {Scanlan, D J and Ostrowski, M and Mazard, S and Dufresne, A and Garczarek, L and Hess, W R and Post, A F and Hagemann, M and Paulsen, I and Partensky, F} } @article {Gadler2009, title = {Enantiocomplementary inverting sec-alkylsulfatase activity in cyano- and thio-bacteria Synechococcus and Paracoccus spp.: selectivity enhancement by medium engineering}, journal = {Tetrahedron: Asymmetry}, volume = {20}, year = {2009}, note = {tex.mendeley-tags: rcc}, pages = {115{\textendash}118}, keywords = {rcc}, doi = {10.1016/j.tetasy.2009.01.007}, author = {Gadler, Petra and Reiter, Tamara C and Hoelsch, Kathrin and Weuster-Botz, Dirk and Fabe, Kurt} } @article {Liu2009, title = {Extreme diversity in noncalcifying haptophytes explains a major pigment paradox in open oceans}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, year = {2009}, note = {tex.mendeley-tags: 2009,rcc,sbr?hyto?ppo}, pages = {12803{\textendash}12808}, keywords = {2009, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1073/pnas.0905841106}, author = {Liu, H and Probert, I and Uitz, J and Claustre, H and Aris-Brossou, S and Frada, M and Not, F and de Vargas, C} } @article {Worden2009, title = {Green evolution and dynamic adaptations revealed by genomes of the marine picoeukaryotes Micromonas}, journal = {Science}, volume = {324}, year = {2009}, note = {tex.mendeley-tags: RCC299,RCC827}, pages = {268{\textendash}272}, abstract = {The photosynthetic picoeukaryote Micromonas thrives from tropical to polar marine ecosystems and belongs to an anciently diverged sister clade to land plants. We sequenced genomes from two Micromonas isolates (22 Mb, CCMP1545; 21 Mb, RCC299) and the results improve understanding of their ecology and green-lineage evolution. Despite high 18S rDNA sequence identity, only 90\% of their predicted genes were shared. Novel intronic repeat elements in CCMP1545, otherwise found only in metagenomic data, and unique riboswitch arrangements emphasized their independent evolutionary paths. Phylogenomic profiles revealed putative ancestral features, but also indicated selection/acquisition processes are actively shaping a {\textquoteleft}unique{\textquoteright} gene pool in each differently than {\textquoteleft}core{\textquoteright} genes. Current climate-change trajectories are predicted to produce conditions favoring picophytoplankton, making Micromonas potential indicators of biological change in ocean ecosystems.}, keywords = {rcc, RCC299, RCC827, SBR$_\textrmP$hyto$_\textrmD$PO, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.1126/science.1167222}, author = {Worden, A Z and Lee, J.- H and Mock, T and Rouz{\'e}, P and Simmons, M P and Aerts, A L and Allen, A E and Cuvelier, M L and Derelle, E and Everett, M V and Foulon, E and Grimwood, J and Gundlach, H and Henrissat, B and Napoli, C and McDonald, S M and Parker, M S and Rombauts, S and Salamov, A and Von Dassow, P and Badger, J H and Coutinho, P M and Demir, E and Dubchak, I and Gentemann, C and Eikrem, W and Gready, J E and John, U and Lanier, W and Lindquist, E A and Lucas, S and Mayer, K F X and Moreau, H and Not, F and Otillar, R and Panaud, O and Pangilinan, J and Paulsen, I and Piegu, B and Poliakov, A and Robbens, S and Schmutz, J and Toulza, E and Wyss, T and Zelensky, A and Zhou, K and Armbrust, E V and Bhattacharya, D and Goodenough, U W and Van de Peer, Y and Grigoriev, I V} } @article {Wolhowe2009, title = {Growth phase dependent hydrogen isotopic fractionation in alkenone-producing haptophytes}, journal = {Biogeosciences}, volume = {6}, number = {8}, year = {2009}, note = {ISBN: 1726-4170 tex.mendeley-tags: 2009,rcc}, pages = {1681{\textendash}1694}, abstract = {Recent works have investigated use of the hydrogen isotopic composition Of C-37 alkenones (delta D-K37s), lipid biomarkers of certain haptophyte microalgae, as an independent paleosalinity proxy. We discuss herein the factors impeding the success of such an application and identify the potential alternative use of delta D-K37s measurements as a proxy for non-thermal, physiological stress impacts on the U-37(K{\textquoteright}) paleotemperature index. Batch-culture experiments with the haptophyte Emiliania huxleyi (CCMP 1742) were conducted to determine the magnitude and variability of the isotopic contrasts between individual C-37 alkenones. Further experiments were conducted with Emiliania huxleyi (CCMP 1742) and Gephyrocapsa oceanica (PZ3-1) to determine whether, and to what extent, delta D-K37s varies between the physiological extremes of nutrient-replete exponential growth and nutrient-depleted senescence. Emiliania huxleyi was observed to exhibit an isotopic contrast between di- and tri-unsaturated C-37 alkenones (alpha(K37:3-K37:2)approximate to 0.97) that is nearly identical to that reported recently by others for environmental samples. Furthermore, this contrast appears to be constant with growth stage. The consistency of the offset across different growth stages suggests that a single, well-defined value for alpha(K37:3-K37:2) may exist and that its use in an isotope mass-balance will allow accurate determination of delta D values for individual alkenones without having to rely on time- and labor-intensive chemical separations. The isotopic fractionation between growth medium and C-37 alkenones was observed to increase dramatically upon the onset of nutrient-depletion-induced senescence, suggesting that delta D-K37s, may serve as an objective tool for recognizing and potentially correcting, at least semi-quantitatively, for the effects of nutrient stress on U-37(K{\textquoteright}) temperature records.}, keywords = {2009, rcc, RCC1300, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.5194/bg-6-1681-2009}, author = {Wolhowe, M D and Prahl, F G and Probert, I and Maldonado, M} } @article {Monier2009, title = {Horizontal gene transfer of an entire metabolic pathway between a eukaryotic alga and its DNA virus}, journal = {Genome Research}, volume = {19}, year = {2009}, note = {tex.mendeley-tags: 2009,rcc,sbr?hyto?ppo}, pages = {1441{\textendash}1449}, keywords = {2009, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1101/gr.091686.109}, author = {Monier, A and Pagarete, A and Allen, M J and Read, B A and de Vargas, C and Claverie, J M and Ogata, H} } @article {Richier2009, title = {Light-dependent transcriptional regulation of genes of biogeochemical interest in the diploid and haploid life cycle stages of Emiliania huxleyi}, journal = {Applied and Environmental Microbiology}, volume = {75}, year = {2009}, note = {Edition: 2009/03/24 ISBN: 1098-5336 (Electronic) tex.mendeley-tags: 2009,rcc,sbr?hyto?ppo}, pages = {3366{\textendash}3369}, abstract = {The expression of genes of biogeochemical interest in calcifying and noncalcifying life stages of the coccolithophore Emiliania huxleyi was investigated. Transcripts potentially involved in calcification were tested through a light-dark cycle. These transcripts were more abundant in calcifying cells and were upregulated in the light. Their application as potential candidates for in situ biogeochemical proxies is also suggested.}, keywords = {2009, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1128/aem.02737-08}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=19304825}, author = {Richier, S and Kerros, M E and de Vargas, C and Haramaty, L and Falkowski, P G and Gattuso, J P} } @article {Ota2009, title = {Partenskyella glossopodia gen. et sp. nov., the first report of chlorarachniophyte that lacks pyrenoid}, journal = {Protist}, volume = {160}, year = {2009}, note = {tex.mendeley-tags: 2009,rcc,sbr?hyto$_\textrmd$ipo}, pages = {137{\textendash}150}, keywords = {2009, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.1016/j.protis.2008.09.003}, author = {Ota, S and Vaulot, D and Le Gall, F and Yabuki, A and Ishida, K} } @article {Sharon2009, title = {Photosystem I gene cassettes are present in marine virus genomes}, journal = {Nature}, volume = {461}, number = {7261}, year = {2009}, note = {Publisher: Macmillan Publishers Limited. All rights reserved tex.mendeley-tags: RCC307}, pages = {258{\textendash}262}, keywords = {RCC307, SBR$_\textrmP$hyto$_\textrmP$PM}, doi = {10.1038/nature08284}, url = {http://dx.doi.org/10.1038/nature08284 http://www.nature.com/nature/journal/v461/n7261/suppinfo/nature08284_S1.html}, author = {Sharon, Itai and Alperovitch, Ariella and Rohwer, Forest and Haynes, Matthew and Glaser, Fabian and Atamna-Ismaeel, Nof and Pinter, Ron Y and Partensky, Fr{\'e}d{\'e}ric and Koonin, Eugene V and Wolf, Yuri I and Nelson, Nathan and B{\'e}j{\`a}, Oded} } @article {Six2009, title = {Photosystem II and pigment dynamics among ecotypes of the green alga Ostreococcus}, journal = {Plant Physiology}, volume = {151}, year = {2009}, note = {tex.mendeley-tags: RCC809}, pages = {379{\textendash}390}, abstract = {We investigated the photophysiological response of three ecotypes of the picophytoplankter Ostreococcus and a larger prasinophyte Pyramimonas obovata to a sudden increase in light irradiance. The deepwater Ostreococcus sp. RCC809 showed very high susceptibility to primary photoinactivation, likely a consequence of high oxidative stress, which may relate to the recently noted plastid terminal oxidase activity in this strain. The three Ostreococcus ecotypes were all able of deploying modulation of photosystem II repair cycle in order to cope with the light increase, but the effective clearance of photoinactivated D1 protein appeared to be slower in the deep water Ostreococcus sp. RCC809, suggesting that this step is rate-limiting in the photosystem II repair cycle in this strain. The deepwater Ostreococcus moreover accumulated lutein and showed substantial use of the xanthophyll cycle under light stress, demonstrating its high sensitivity to light fluctuations. The sustained component of the non-photochemical quenching of fluorescence correlated well with the xanthophyll de-epoxidation activity. Comparisons with the larger prasinophyte Pyramimonas obovata suggest that the photophysiology of Ostreococcus ecotypes requires high photosystem II repair rates to counter a high susceptibility to photoinactivation, consistent with low pigment package effects in their minute-sized cells.}, keywords = {rcc, RCC809, SBR$_\textrmP$hyto$_\textrmP$PM}, doi = {10.1104/pp.109.140566}, author = {Six, C and Sherrard, R and Lionard, M and Roy, S and Campbell, D A} } @article {Langer2009, title = {Strain-specific responses of Emiliania huxleyi to changing seawater carbonate chemistry}, journal = {Biogeosciences}, volume = {6}, number = {11}, year = {2009}, note = {ISBN: 1726-4170 tex.mendeley-tags: 2009,rcc}, pages = {2637{\textendash}2646}, abstract = {Four strains of the coccolithophore E. huxleyi (RCC1212, RCC1216, RCC1238, RCC1256) were grown in dilute batch culture at four CO2 levels ranging from similar to 200 mu atm to similar to 1200 mu atm. Growth rate, particulate organic carbon content, and particulate inorganic carbon content were measured, and organic and inorganic carbon production calculated. The four strains did not show a uniform response to carbonate chemistry changes in any of the analysed parameters and none of the four strains displayed a response pattern previously described for this species. We conclude that the sensitivity of different strains of E. huxleyi to acidification differs substantially and that this likely has a genetic basis. We propose that this can explain apparently contradictory results reported in the literature.}, keywords = {2009, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.5194/bg-6-2637-2009}, author = {Langer, G and Nehrke, G and Probert, I and Ly, J and Ziveri, P} } @article {VonDassow2009, title = {Transcriptome analysis of functional differentiation between haploid and diploid cells of Emiliania huxleyi, a globally significant photosynthetic calcifying cell}, journal = {Genome Biology}, volume = {10}, number = {10}, year = {2009}, note = {tex.mendeley-tags: 2009,rcc,rcc1216,rcc1217,sbr?hyto?ppo}, pages = {R114}, abstract = {BACKGROUND:Eukaryotes are classified as either haplontic, diplontic, or haplo-diplontic, depending on which ploidy levels undergo mitotic cell division in the life cycle. Emiliania huxleyi is one of the most abundant phytoplankton species in the ocean, playing an important role in global carbon fluxes, and represents haptophytes, an enigmatic group of unicellular organisms that diverged early in eukaryotic evolution. This species is haplo-diplontic. Little is known about the haploid cells, but they have been hypothesized to allow persistence of the species between the yearly blooms of diploid cells. We sequenced over 38000 Expressed Sequence Tags (ESTs) from haploid and diploid E. huxleyi normalized cDNA libraries to identify genes involved in important processes specific to each life phase (2N calcification or 1N motility), and to better understand the haploid phase of this prominent haplo-diplontic organism.RESULTS:The haploid and diploid transcriptomes showed a dramatic differentiation, with [almost equal to]20\% greater transcriptome richness in diploid cells than in haploid cells and only [less than or equal to]50\% of transcripts estimated to be common between the two phases. The major functional category of transcripts differentiating haploids included signal transduction and motility genes. Diploid-specific transcripts included Ca2+, H+, and HCO3- pumps. Potential factors differentiating the transcriptomes included haploid-specific Myb transcription factor homologs and an unusual diploid-specific histone H4 homolog.CONCLUSIONS:This study permitted the identification of genes likely involved in diploid-specific biomineralization, haploid-specific motility, and transcriptional control. Greater transcriptome richness in diploid cells suggests they may be more versatile for exploiting a diversity of rich environments whereas haploid cells are intrinsically more streamlined.}, keywords = {2009, rcc, RCC1216, rcc1217, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1186/gb-2009-10-10-r114}, url = {http://genomebiology.com/2009/10/10/R114}, author = {von Dassow, Peter and Ogata, Hiroyuki and Probert, Ian and Wincker, Patrick and Da Silva, Corinne and Audic, St{\'e}phane and Claverie, Jean-Michel and de Vargas, Colomban} } @article {Frada2008, title = {The {\textquotedblleft}Cheshire Cat{\textquotedblright} escape strategy of the coccolithophore Emiliania huxleyi in response to viral infection}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto?ppo}, pages = {15944{\textendash}15949}, abstract = {The coccolithophore is one of the most successful eukaryotes in modern oceans. The two phases in its haplodiploid life cycle exhibit radically different phenotypes. The diploid calcified phase forms extensive blooms, which profoundly impact global biogeochemical equilibria. By contrast, the ecological role of the noncalcified haploid phase has been completely overlooked. Giant phycodnaviruses ( viruses, EhVs) have been shown to infect and lyse diploid-phase cells and to be heavily implicated in the regulation of populations and the termination of blooms. Here, we demonstrate that the haploid phase of is unrecognizable and therefore resistant to EhVs that kill the diploid phase. We further show that exposure of diploid to EhVs induces transition to the haploid phase. Thus we have clearly demonstrated a drastic difference in viral susceptibility between life cycle stages with different ploidy levels in a unicellular eukaryote. Resistance of the haploid phase of provides an escape mechanism that involves separation of meiosis from sexual fusion in time, thus ensuring that genes of dominant diploid clones are passed on to the next generation in a virus-free environment. These {\^a}{\texteuro}{\oe}Cheshire Cat{\^a}{\texteuro} ecological dynamics release host evolution from pathogen pressure and thus can be seen as an opposite force to a classic {\^a}{\texteuro}{\oe}Red Queen{\^a}{\texteuro} coevolutionary arms race. In , this phenomenon can account for the fact that the selective balance is tilted toward the boom-and-bust scenario of optimization of both growth rates of calcifying cells and infectivity of EhVs.}, keywords = {2008, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1073/pnas.0807707105}, author = {Frada, Miguel and Probert, Ian and Allen, Michael J and Wilson, William H and de Vargas, Colomban} } @article {Jancek2008, title = {Clues about the genetic basis of adaptation emerge from comparing the proteomes of two Ostreococcus ecotypes (Chlorophyta, Prasinophyceae)}, journal = {Molecular Biology and Evolution}, volume = {25}, number = {11}, year = {2008}, note = {Edition: 2008/08/06 ISBN: 1537-1719 (Electronic) 0737-4038 (Linking) tex.mendeley-tags: RCC,rcc}, pages = {2293{\textendash}2300}, abstract = {We compared the proteomes of two picoplanktonic Ostreococcus unicellular green algal ecotypes to analyze the genetic basis of their adaptation with their ecological niches. We first investigated the function of the species-specific genes using Gene Ontology databases and similarity searches. Although most species-specific genes had no known function, we identified several species-specific functions involved in various cellular processes, which could be critical for environmental adaptations. Additionally, we investigated the rate of evolution of orthologous genes and its distribution across chromosomes. We show that faster evolving genes encode significantly more membrane or excreted proteins, consistent with the notion that selection acts on cell surface modifications that is driven by selection for resistance to viruses and grazers, keystone actors of phytoplankton evolution. The relationship between GC content and chromosome length also suggests that both strains have experienced recombination since their divergence and that lack of recombination on the two outlier chromosomes could explain part of their peculiar genomic features, including higher rates of evolution.}, keywords = {adaptation, Base Composition, Chlorophyta/*genetics, Ecosystem, Physiological/*genetics, Phytoplankton/genetics, Proteome/*genetics, rcc, Species Specificity}, doi = {10.1093/molbev/msn168}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=18678753}, author = {Jancek, S and Gourbiere, S and Moreau, H and Piganeau, G} } @article {Six2008, title = {Contrasting photoacclimation strategies in ecotypes of the eukayotic picoplankter {\textexclamdown}i{\textquestiondown}Ostreococcus{\textexclamdown}/i{\textquestiondown}}, journal = {Limnology and Oceanography}, volume = {53}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, pages = {255{\textendash}265}, abstract = {Ostreococcus, the smallest known marine picoeukaryote, includes low- and high-light ecotypes. To determine the basis for niche partitioning between Ostreococcus sp. RCC809, isolated from the bottom of the tropical Atlantic euphotic zone, and the lagoon strain Ostreococcus tauri, we studied their photophysiologies under growth irradiances from 15 mmol photons m22 s21 to 800 mmol photons m22 s21 with a common nutrient replete regime. With increasing growth irradiance, both strains down-regulated cellular chlorophyll a and chlorophyll b (Chl a and Chl b) content, increased xanthophyll de-epoxidation correlated with nonphotochemical excitation quenching, and accumulated lutein. Ribulose-1,5-bisphosphate carboxylase/oxygenase content remained fairly stable. Under low-growth irradiances of 15{\textendash}80 mmol photons m22 s21, O. sp. RCC809 had equivalent or slightly higher growth rates, lower Chl a, a higher Chl b : Chl a ratio, and a larger photosystem II (PSII) antenna than O. tauri. O. tauri was more phenotypically plastic in response to growth irradiance, with a larger dynamic range in growth rate, Chl a, photosystem cell content, and cellular absorption cross-section of PSII. Estimating the amino acid and nitrogen costs for photoacclimation showed that the deep-sea oceanic O. sp. RCC809 relies largely on lower nitrogen cost changes in PSII antenna size to achieve a limited range of s-type light acclimation. O. sp. RCC809, however, suffers photoinhibition under higher light. This limited capacity for photoacclimation is compatible with the stable low-light and nutrient conditions at the base of the euphotic layer of the tropical Atlantic Ocean. In the more variable, high-nutrient, lagoon environment, O. tauri can afford to use a higher cost n-type acclimation of photosystem contents to exploit a wider range of light.}, keywords = {2008, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, doi = {10.4319/lo.2008.53.1.0255}, author = {Six, C and Finkel, Z V and Rodriguez, F and Marie, D and Partensky, F and Campbell, D A} } @article {Vaulot2008, title = {The diversity of small eukaryotic phytoplankton ({\textexclamdown}3 {\textmu}m) in marine ecosystems}, volume = {32}, number = {5}, year = {2008}, note = {Publication Title: FEMS microbiology reviews tex.mendeley-tags: 2008,rcc,sbr?hyto$_\textrmd$ipo}, pages = {795{\textendash}820}, abstract = {Small cells dominate photosynthetic biomass and primary production in many marine ecosystems. Traditionally, picoplankton refers to cells {\textexclamdown} or =2 microm. Here we extend the size range of the organisms considered to 3 microm, a threshold often used operationally in field studies. While the prokaryotic component of picophytoplankton is dominated by two genera, Prochlorococcus and Synechococcus, the eukaryotic fraction is much more diverse. Since the discovery of the ubiquitous Micromonas pusilla in the early 1950s, just over 70 species that can be {\textexclamdown}3 microm have been described. In fact, most algal classes contain such species. Less than a decade ago, culture-independent approaches (in particular, cloning and sequencing, denaturing gradient gel electrophoresis, FISH) have demonstrated that the diversity of eukaryotic picoplankton is much more extensive than could be assumed from described taxa alone. These approaches revealed the importance of certain classes such as the Prasinophyceae but also unearthed novel divisions such as the recently described picobiliphytes. In the last couple of years, the first genomes of photosynthetic picoplankton have become available, providing key information on their physiological capabilities. In this paper, we discuss the range of methods that can be used to assess small phytoplankton diversity, present the species described to date, review the existing molecular data obtained on field populations, and end up by looking at the promises offered by genomics.}, keywords = {2008, diversity, genomics, Marine ecosystems, Micro-algae, picoplankton, rcc, sbr?hyto$_\textrmd$ipo, taxonomy}, author = {Vaulot, Daniel and Eikrem, Wenche and Viprey, Manon and Moreau, Herv{\'e}} } @article {Foulon2008, title = {Ecological niche partitioning in the picoplanktonic green alga Micromonas pusilla: evidence from environmental surveys using phylogenetic probes}, journal = {Environmental Microbiology}, volume = {10}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto$_\textrmd$ipo}, pages = {2433{\textendash}2443}, keywords = {2008, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.1111/j.1462-2920.2008.01673.x}, author = {Foulon, E and Not, F and Jalabert, F and Cariou, T and Massana, R and Simon, N} } @article {Claquin2008, title = {Effects of temperature on photosynthetic parameters and TEP production in eight species of marine microalgae}, journal = {Aquatic Microbial Ecology}, volume = {51}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc}, pages = {1{\textendash}11}, keywords = {2008, rcc, SBR$_\textrmP$hyto}, doi = {10.3354/ame01187}, author = {Claquin, Pascal and Probert, Ian and Lefebvre, S{\'e}bastien and Veron, Benoit} } @article {Misumi2008, title = {Genome analysis and its significance in four unicellular algae, Cyanidioshyzon merolae, Ostreococcus tauri, Chlamydomonas reinhardtii, and Thalassiosira pseudonana}, journal = {Journal of Plant Research}, volume = {121}, number = {1}, year = {2008}, note = {tex.mendeley-tags: RCC,rcc}, pages = {3{\textendash}17}, abstract = {Algae play a more important role than land plants in the maintenance of the global environment and productivity. Progress in genome analyses of these organisms means that we can now obtain information on algal genomes, global annotation and gene expression. The full genome information for several algae has already been analyzed. Whole genomes of the red alga Cyanidioshyzon merolae, the green algae Ostreococcus tauri and Chlamydomonas reinhardtii, and the diatom Thalassiosira pseudonana have been sequenced. Genome composition and the features of cells among the four algae were compared. Each alga maintains basic genes as photosynthetic eukaryotes and possesses additional gene groups to represent their particular characteristics. This review discusses and introduces the latest research that makes the best use of the particular features of each organism and the significance of genome analysis to study biological phenomena. In particular, examples of post-genome studies of organelle multiplication in C. merolae based on analyzed genome information are presented.}, keywords = {rcc}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=18074102}, author = {Misumi, O and Yoshida, Y and Nishida, K and Fujiwara, T and Sakajiri, T and Hirooka, S and Nishimura, Y and Kuroiwa, T} } @article {Derelle2008, title = {Life-cycle and genome of OtV5, a large DNA virus of the pelagic marine unicellular green alga {\textexclamdown}i{\textquestiondown}Ostreococcus tauri{\textexclamdown}/i{\textquestiondown}}, journal = {PLoS ONE}, volume = {3}, number = {5}, year = {2008}, note = {Publisher: Public Library of Science tex.mendeley-tags: RCC,rcc}, pages = {e2250}, abstract = {Large DNA viruses are ubiquitous, infecting diverse organisms ranging from algae to man, and have probably evolved from an ancient common ancestor. In aquatic environments, such algal viruses control blooms and shape the evolution of biodiversity in phytoplankton, but little is known about their biological functions. We show that Ostreococcus tauri, the smallest known marine photosynthetic eukaryote, whose genome is completely characterized, is a host for large DNA viruses, and present an analysis of the life-cycle and 186,234 bp long linear genome of OtV5. OtV5 is a lytic phycodnavirus which unexpectedly does not degrade its host chromosomes before the host cell bursts. Analysis of its complete genome sequence confirmed that it lacks expected site-specific endonucleases, and revealed the presence of 16 genes whose predicted functions are novel to this group of viruses. OtV5 carries at least one predicted gene whose protein closely resembles its host counterpart and several other host-like sequences, suggesting that horizontal gene transfers between host and viral genomes may occur frequently on an evolutionary scale. Fifty seven percent of the 268 predicted proteins present no similarities with any known protein in Genbank, underlining the wealth of undiscovered biological diversity present in oceanic viruses, which are estimated to harbour 200Mt of carbon.}, keywords = {rcc}, doi = {10.1371/journal.pone.0002250}, url = {http://dx.doi.org/10.1371/journal.pone.0002250}, author = {Derelle, Evelyne and Ferraz, Conchita and Escande, Marie-Line and Eycheni{\'e}, Sophie and Cooke, Richard and Piganeau, Gwenael and Desdevises, Yves and Bellec, Laure and Moreau, Herv{\'e} and Grimsley, Nigel} } @article {Descles2008, title = {New tools for labeling silica in living diatoms}, journal = {New Phytologist}, volume = {177}, number = {3}, year = {2008}, note = {ISBN: 0028-646X tex.mendeley-tags: rcc}, pages = {822{\textendash}829}, abstract = {Silicon biomineralization is a widespread mechanism found in several kingdoms that concerns both unicellular and multicellular organisms. As a result of genomic and molecular tools, diatoms have emerged as a good model for biomineralization studies and have provided most of the current knowledge on this process. However, the number of techniques available to study its dynamics at the cellular level is still rather limited. Here, new probes were developed specifically to label the pre-existing or the newly synthesized silica frustule of several diatoms species. It is shown that the LysoTracker Yellow HCK-123, which can be used to visualize silica frustules with common filter sets, presents an enhanced signal-to-noise ratio and allows details of the frustules to be imaged without of the use of ionophores. It is also demonstrated that methoxysilane derivatives can be coupled to fluorescein-5-isothiocyanate (FITC) to preferentially label the silica components of living cells. The coupling of labeling procedures might help to address the challenging question of the process of frustule exocytosis.}, keywords = {3D-imaging, BACILLARIOPHYCEAE, BIOLOGY, biomineralization, DEPOSITION, diatoms, exocytosis, FLUORESCENT, nanopattern, pH, phaeodactylum-tricornutum, PLANTS, rcc, THALASSIOSIRA-PSEUDONANA, ultrastructure, VESICLE}, doi = {10.1111/j.1469-8137.2007.02303.x}, author = {Descles, J and Vartanian, M and El Harrak, A and Quinet, M and Bremond, N and Sapriel, G and Bibette, J and Lopez, P J} } @article {Cardol2008, title = {An original adaptation of photosynthesis in the marine green alga Ostreococcus}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, number = {22}, year = {2008}, note = {tex.mendeley-tags: RCC745,RCC809}, pages = {7881{\textendash}7886}, abstract = {Adaptation of photosynthesis in marine environment has been examined in two strains of the green, picoeukaryote : OTH95, a surface/high-light strain, and RCC809, a deep-sea/low-light strain. Differences between the two strains include changes in the light-harvesting capacity, which is lower in OTH95, and in the photoprotection capacity, which is enhanced in OTH95. Furthermore, RCC809 has a reduced maximum rate of O evolution, which is limited by its decreased photosystem I (PSI) level, a possible adaptation to Fe limitation in the open oceans. This decrease is, however, accompanied by a substantial rerouting of the electron flow to establish an HO-to-HO cycle, involving PSII and a potential plastid plastoquinol terminal oxidase. This pathway bypasses electron transfer through the cytochrome complex and allows the pumping of {\^a}{\texteuro}{\oe}extra{\^a}{\texteuro} protons into the thylakoid lumen. By promoting the generation of a large {\^I}{\textquotedblright}pH, it facilitates ATP synthesis and nonphotochemical quenching when RCC809 cells are exposed to excess excitation energy. We propose that the diversion of electrons to oxygen downstream of PSII, but before PSI, reflects a common and compulsory strategy in marine phytoplankton to bypass the constraints imposed by light and/or nutrient limitation and allow successful colonization of the open-ocean marine environment.}, keywords = {rcc, RCC745, RCC809}, doi = {10.1073/pnas.0802762105}, url = {http://www.pnas.org/content/105/22/7881.abstract}, author = {Cardol, Pierre and Bailleul, Benjamin and Rappaport, Fabrice and Derelle, Evelyne and Baal, Daniel and Breyton, C{\'e}cile and Bailey, Shaun and Wollman, Francis Andr{\'e} and Grossman, Arthur and Moreau, Herv{\'e} and Finazzi, Giovanni} } @article {Fountain2008, title = {Permeation properties of a P2X receptor in the green algae Ostreococcus tauri}, journal = {Journal of Biological Chemistry}, volume = {283}, number = {22}, year = {2008}, note = {ISBN: 0021-9258 tex.mendeley-tags: RCC,rcc}, pages = {15122{\textendash}15126}, abstract = {We have cloned a P2X receptor (OtP2X) from the green algae Ostreococcus tauri. The 42-kDa receptor shares similar to 28\% identity with human P2X receptors and 23\% with the Dictyostelium P2X receptor. ATP application evoked flickery single channel openings in outside-out membrane patches from human embryonic kidney 293 cells expressing OtP2X. Whole-cell recordings showed concentration-dependent cation currents reversing close to zero mV; ATP gave a half-maximal current at 250 mu m. alpha beta-Methylene-ATP evoked only small currents in comparison to ATP (EC50 {\textquestiondown} 5 mM). 2{\textquoteright},3{\textquoteright}-O-(4-Benzoylbenzoyl)-ATP, beta gamma-imido-ATP, ADP, and several other nucleotide triphosphates did not activate any current. The currents evoked by 300 mu m ATP were not inhibited by 100 mu m suramin, pyridoxal-phosphate-6-azophenyl-2{\textquoteright},4{\textquoteright}-disulfonic acid, 2{\textquoteright},3{\textquoteright}-O-(2,4,6-trinitrophenol)-ATP, or copper. Ion substitution experiments indicated permeabilities relative to sodium with the rank order calcium {\textquestiondown} choline {\textquestiondown} Tris {\textquestiondown} tetraethylammonium {\textquestiondown} N-methyl-D-glucosamine. However, OtP2X had a low relative calcium permeability (P-Ca/P-Na = 0.4) in comparison with other P2X receptors. This was due at least in part to the presence of an asparagine residue (Asn(353)) at a position in the second transmembrane domain in place of the aspartate that is completely conserved in all other P2X receptor subunits, because replacement of Asn(353) with aspartate increased calcium permeability by similar to 50\%. The results indicate that the ability of ATP to gate cation permeation across membranes exists in cells that diverged in evolutionary terms from animals about I billion years ago.}, keywords = {CELLS, CHANNELS, EXTRACELLULAR ATP, FAMILY, FUNCTIONAL-CHARACTERIZATION, PERMEABILITY, PHARMACOLOGY, rcc}, doi = {10.1074/jbc.M801512200}, url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2397467}, author = {Fountain, S J and Cao, L S and Young, M T and North, R A} } @article {Bowler2008, title = {The Phaeodactylum genome reveals the evolutionary history of diatom genomes}, journal = {Nature}, volume = {456}, number = {7219}, year = {2008}, note = {Publisher: Macmillan Publishers Limited. All rights reserved tex.mendeley-tags: 2008,rcc,sbr?hyto?ppo}, pages = {239{\textendash}244}, keywords = {2008, rcc, SBR$_\textrmP$hyto$_\textrmE$PPOdipo, sbr?hyto?ppo}, doi = {10.1038/nature07410}, url = {http://dx.doi.org/10.1038/nature07410 http://www.nature.com/nature/journal/v456/n7219/suppinfo/nature07410_S1.html}, author = {Bowler, Chris and Allen, Andrew E and Badger, Jonathan H and Grimwood, Jane and Jabbari, Kamel and Kuo, Alan and Maheswari, Uma and Martens, Cindy and Maumus, Florian and Otillar, Robert P and Rayko, Edda and Salamov, Asaf and Vandepoele, Klaas and Beszteri, Bank and Gruber, Ansgar and Heijde, Marc and Katinka, Michael and Mock, Thomas and Valentin, Klaus and Verret, Frederic and Berges, John A and Brownlee, Colin and Cadoret, Jean-Paul and Chiovitti, Anthony and Choi, Chang Jae and Coesel, Sacha and De Martino, Alessandra and Detter, J Chris and Durkin, Colleen and Falciatore, Angela and Fournet, Jerome and Haruta, Miyoshi and Huysman, Marie J J and Jenkins, Bethany D and Jiroutova, Katerina and Jorgensen, Richard E and Joubert, Yolaine and Kaplan, Aaron and Kroger, Nils and Kroth, Peter G and La Roche, Julie and Lindquist, Erica and Lommer, Markus and Martin-Jezequel, Veronique and Lopez, Pascal J and Lucas, Susan and Mangogna, Manuela and McGinnis, Karen and Medlin, Linda K and Montsant, Anton and Secq, Marie-Pierre Oudot-Le and Napoli, Carolyn and Obornik, Miroslav and Parker, Micaela Schnitzler and Petit, Jean-Louis and Porcel, Betina M and Poulsen, Nicole and Robison, Matthew and Rychlewski, Leszek and Rynearson, Tatiana A and Schmutz, Jeremy and Shapiro, Harris and Siaut, Magali and Stanley, Michele and Sussman, Michael R and Taylor, Alison R and Vardi, Assaf and von Dassow, Peter and Vyverman, Wim and Willis, Anusuya and Wyrwicz, Lucjan S and Rokhsar, Daniel S and Weissenbach, Jean and Armbrust, E Virginia and Green, Beverley R and Van de Peer, Yves and Grigoriev, Igor V} } @article {Rodriguez2008, title = {Phylogenetic and morphological characterization of the green algae infesting blue mussel Mytilus edulis in the North and South Atlantic}, journal = {Diseases of Aquatic Organisms}, volume = {81}, year = {2008}, note = {tex.mendeley-tags: RCC894}, pages = {231{\textendash}240}, keywords = {rcc, RCC894, SBR$_\textrmP$hyto$_\textrmD$PO}, doi = {10.3354/dao01956}, author = {Rodriguez, F and Feist, S W and Guillou, L and Harkestad, L S and Bateman, K and Renault, T and Mortensen, S} } @article {LeGall2008, title = {Picoplankton diversity in the south-east pacific ocean from cultures}, journal = {Biogeosciences}, volume = {5}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, pages = {203{\textendash}214}, keywords = {2008, PICOFUNPAC, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, doi = {10.5194/bg-5-203-2008}, author = {Le Gall, F and Rigaut-Jalabert, F and Marie, D and Garczareck, L and Viprey, M and Godet, A and Vaulot, D} } @article {Jouenne2008, title = {Plankton taxonomy in the computer age}, journal = {Cahiers de Biologie Marine}, volume = {49}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto$_\textrmd$ipo}, pages = {355{\textendash}367}, abstract = {

Preservation of biodiversity starts with knowledge of biodiversity. Based on this principle, numerous projects combining taxonomy and web-based technologies have developed over the last fifteen years, often with the aim of listing all living organisms described to date. Individual lists have been progressively incorporated into federative projects, such as Species 2000 or the Global Biodiversity Information Facility (GBIF). Nowadays, modern taxonomy is splited up between traditionalism and pragmatism. The Internet can provide new advantages to taxonomy (accessibility and efficiency) without reducing quality. In the future, it would be highly desirable to ba able to publish species descriptions and revisions on permanent web-sites on the model of GENBANK. Biodiversity inventory projects should converge to a very limited number of portals (e.g. Encyclopedia of Life). We illustrate these concepts by presenting Plankton*Net an interactive web site dedicated to the taxonomy and images of plankton.

}, keywords = {2008, ? No DOI found, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, author = {Jouenne, F and Probert, I and Vaulot, D} } @article {Viprey2008, title = {Wide genetic diversity of picoplanktonic green algae (Chloroplastida) in the Mediterranean Sea uncovered by a phylum-biased PCR approach}, journal = {Environmental Microbiology}, volume = {10}, number = {7}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto$_\textrmd$ipo}, pages = {1804{\textendash}1822}, abstract = {The genetic diversity of picoplanktonic (i.e. cells that can pass through a 3 mum pore-size filter) green algae was investigated in the Mediterranean Sea in late summer by a culture-independent approach. Genetic libraries of the 18S rRNA gene were constructed using two different primer sets. The first set is commonly used to amplify the majority of eukaryotic lineages, while the second was composed of a general eukaryotic forward primer and a reverse primer biased towards the phylum Chloroplastida. A total of 3980 partial environmental sequences were obtained: 1668 using the general eukaryotic primer set and 2312 using the Chloroplastida-biased primer set. Of these sequences, 65 (4\%) and 594 (26\%) belonged to the Chloroplastida respectively. A 99.5\% sequence similarity cut-off value allowed classification of these 659 Chloroplastida sequences into 74 different operational taxonomic units. A majority of the Chloroplastida sequences (99\%) belonged to the prasinophytes. In addition to the seven independent prasinophyte lineages previously described, we discovered two new clades (clades VIII and IX), as well as a significant genetic diversity at the species and subspecies levels, notably among the genera Crustomastix, Dolichomastix and Mamiella (Mamiellales), but also within Pyramimonas and Halosphaera (Pyramimonadales). Such diversity within prasinophytes has not previously been observed by cloning approaches, illustrating the power of using targeted primers for clone library construction. Prasinophyte assemblages differed especially in relation to nutrient levels. Micromonas and Ostreococcus were mainly recovered from mesotrophic areas, whereas Mamiella, Crustomastix and Dolichomastix were mostly detected in oligotrophic surface waters. Within genera such as Ostreococcus or Crustomastix for which several clades were observed, depth seemed to be the main factor controlling differential distribution of genotypes.}, keywords = {2008, rcc, sbr?hyto$_\textrmd$ipo}, author = {Viprey, Manon and Guillou, Laure and Ferr{\'e}ol, Martial and Vaulot, Daniel} } @article {Robbens2007, title = {The complete chloroplast and mitochondrial DNA sequence of Ostreococcus tauri: organelle genomes of the smallest eukaryote are examples of compaction}, journal = {Molecular Biology and Evolution}, volume = {24}, number = {4}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {956{\textendash}968}, abstract = {The complete nucleotide sequence of the mt (mitochondrial) and cp (chloroplast) genomes of the unicellular green alga Ostreococcus tauri has been determined. The mt genome assembles as a circle of 44,237 bp and contains 65 genes. With an overall average length of only 42 bp for the intergenic regions, this is the most gene-dense mt genome of all Chlorophyta. Furthermore, it is characterized by a unique segmental duplication, encompassing 22 genes and covering 44\% of the genome. Such a duplication has not been observed before in green algae, although it is also present in the mt genomes of higher plants. The quadripartite cp genome forms a circle of 71,666 bp, containing 86 genes divided over a larger and a smaller single-copy region, separated by 2 inverted repeat sequences. Based on genome size and number of genes, the Ostreococcus cp genome is the smallest known among the green algae. Phylogenetic analyses based on a concatenated alignment of cp, mt, and nuclear genes confirm the position of O. tauri within the Prasinophyceae, an early branch of the Chlorophyta.}, keywords = {rcc}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=17251180}, author = {Robbens, S and Derelle, E and Ferraz, C and Wuyts, J and Moreau, H and Van de Peer, Y} } @article {Six2007, title = {Diversity and evolution of phycobilisomes in marine Synechococcus spp. - a comparative genomics study}, journal = {Genome Biology}, volume = {8}, year = {2007}, note = {tex.mendeley-tags: 2007,rcc,sbr?hyto?app}, pages = {R259}, keywords = {2007, rcc, SBR$_\textrmP$hyto, sbr?hyto?app}, doi = {10.1186/gb-2007-8-12-r259}, author = {Six, C and Thomas, J.-C. and Garczarek, L and Ostrowski, M and Dufresne, A and Blot, N and Scanlan, D J and Partensky, F} } @article {Waters2007, title = {Evolutionary analysis of the small heat shock proteins in five complete algal genomes}, journal = {Journal of Molecular Evolution}, volume = {65}, number = {2}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {162{\textendash}174}, abstract = {Small heat shock proteins (sHSPs) are chaperones that are crucial in the heat shock response but also have important nonstress roles within the cell. sHSPs are found in all three domains of life (Bacteria, Archaea, and Eukarya). These proteins are particularly diverse within land plants and the evolutionary origin of the land plant sHSP families is still an open question. Here we describe the identification of 17 small sHSPs from the complete genome sequences of five diverse algae: Chlamydomonas reinhardtii, Cyanidioschyzon merolae, Ostreococcus lucimarinus, Ostreococcus tauri, and Thalassiosira pseudonana. Our analysis indicates that the number and diversity of algal sHSPs are not correlated with adaptation to extreme conditions. While all of the algal sHSPs identified are members of this large and important superfamily, none of these sHSPs are members of the diverse land plant sHSP families. The evolutionary relationships among the algal sHSPs and homologues from bacteria and other eukaryotes are consistent with the hypothesis that the land plant chloroplast and mitochondrion sHSPs did not originate from the endosymbionts of the chloroplast and mitochondria. In addition the evolutionary history of the sHSPs is very different from that of the HSP70s. Finally, our analysis of the algal sHSPs sequences in light of the known sHSP crystal structures and functional data suggests that the sHSPs possess considerable structural and functional diversity.}, keywords = {*Evolution, *Genome, algae, Algae/classification/*genetics, Algal Proteins/*genetics, Amino Acid Sequence, Animals, Chlamydomonas reinhardtii/genetics, Diatoms/genetics, Green/genetics, Heat-Shock Proteins, Molecular, Molecular Sequence Data, phylogeny, Protein, rcc, Red/genetics, Sequence Alignment, Sequence Analysis, Small/*genetics, Species Specificity}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=17684698}, author = {Waters, E R and Rioflorido, I} } @article {Lobanov2007, title = {Evolutionary dynamics of eukaryotic selenoproteomes: large selenoproteomes may associate with aquatic life and small with terrestrial life}, journal = {Genome Biology}, volume = {8}, number = {9}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {R198}, abstract = {BACKGROUND: Selenocysteine (Sec) is a selenium-containing amino acid that is co-translationally inserted into nascent polypeptides by recoding UGA codons. Selenoproteins occur in both eukaryotes and prokaryotes, but the selenoprotein content of organisms (selenoproteome) is highly variable and some organisms do not utilize Sec at all. RESULTS: We analyzed the selenoproteomes of several model eukaryotes and detected 26 and 29 selenoprotein genes in the green algae Ostreococcus tauri and Ostreococcus lucimarinus, respectively, five in the social amoebae Dictyostelium discoideum, three in the fly Drosophila pseudoobscura, and 16 in the diatom Thalassiosira pseudonana, including several new selenoproteins. Distinct selenoprotein patterns were verified by metabolic labeling of O. tauri and D. discoideum with 75Se. More than half of the selenoprotein families were shared by unicellular eukaryotes and mammals, consistent with their ancient origin. Further analyses identified massive, independent selenoprotein losses in land plants, fungi, nematodes, insects and some protists. Comparative analyses of selenoprotein-rich and -deficient organisms revealed that aquatic organisms generally have large selenoproteomes, whereas several groups of terrestrial organisms reduced their selenoproteomes through loss of selenoprotein genes and replacement of Sec with cysteine. CONCLUSION: Our data suggest many selenoproteins originated at the base of the eukaryotic domain and show that the environment plays an important role in selenoproteome evolution. In particular, aquatic organisms apparently retained and sometimes expanded their selenoproteomes, whereas the selenoproteomes of some terrestrial organisms were reduced or completely lost. These findings suggest a hypothesis that, with the exception of vertebrates, aquatic life supports selenium utilization, whereas terrestrial habitats lead to reduced use of this trace element due to an unknown environmental factor.}, keywords = {rcc}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=17880704}, author = {Lobanov, A V and Fomenko, D E and Zhang, Y and Sengupta, A and Hatfield, D L and Gladyshev, V N} } @article {Probert2007a, title = {Light and electron microscope observations of Algirosphaera robusta (Prymnesiophyceae)}, journal = {Journal of Phycology}, volume = {43}, year = {2007}, note = {tex.mendeley-tags: 2007,rcc}, pages = {319{\textendash}332}, keywords = {2007, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.1111/j.1529-8817.2007.00324.x}, author = {Probert, I and Fresnel, J and Billard, C and Geisen, Markus and Young, J R} } @article {Kettler2007, title = {Patterns and implications of gene gain and loss in the evolution of Prochlorococcus}, journal = {PLoS genetics}, volume = {3}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {e231}, keywords = {rcc}, doi = {10.1371/journal.pgen.0030231}, author = {Kettler, G and Martiny, A C and Huang, K and Zucker, J and Coleman, M L and Rodrigue, S and Chen, F and Lapidus, A and Ferriera, S and Johnson, J and Steglich, C and Church, G and Richardson, P and Chisholm, S W} } @article {Dimier2007, title = {Photophysiological properties of the marine picoeukaryote Picochlorum RCC 237 (Trebouxiophyceae, Chlorophyta)}, journal = {Journal of Phycology}, volume = {43}, number = {2}, year = {2007}, note = {ISBN: 0022-3646 tex.mendeley-tags: RCC,rcc}, pages = {275{\textendash}283}, abstract = {The photophysiological properties of strain RCC 237 belonging to the marine picoplanktonic genus Picochlorum, first described by Henley et al., were investigated under different photon flux densities (PFD), ranging from 40 to 400 mu mol photons. m(-2).s(-1), mainly focusing on the development of the xanthophyll cycle and its relationship with the nonphotochemical quenching of fluorescence (NPQ). The functioning of the xanthophyll cycle and its photoprotective role was investigated by applying a progressive increase of PFD and using dithiotreitol and norflurazon to block specific enzymatic reactions in order to study in depth the relationship between xanthophyll cycle and NPQ. These two processes were significantly related only during the gradually increasing light periods and not during stable light periods, where NPQ and zeaxanthin were decoupled. This result reveals that NPQ is a photoprotective process developed by algae only when cells are experiencing increasing PFD or in response to stressful light variations, for instance after a sudden light shift. Results showed that the photobiological properties of Picochlorum strain RCC 237 seem to be well related to the surface water characteristics, as it is able to maintain its photosynthetic characteristics under different PFDs and to quickly activate the xanthophyll cycle under high light.}, keywords = {A FLUORESCENCE, CHLAMYDOMONAS-REINHARDTII, DIATOM PHAEODACTYLUM-TRICORNUTUM, ENERGY-DISSIPATION, fluctuating light, fluorescence quantum yield, MANTONIELLA-SQUAMATA, nonphotochemical quenching of fluorescence, photoacclimation, PHOTOSYNTHETIC APPARATUS, picoplankton, POOL SIZE, rcc, VIOLAXANTHIN DE-EPOXIDASE, Xanthophyll cycle, XANTHOPHYLL-CYCLE, zeaxanthin}, doi = {10.1111/j.1529-8817.2007.00327.x}, author = {Dimier, C and Corato, F and Saviello, G and Brunet, C} } @article {Khan2007, title = {Plastid genome sequence of the cryptophyte alga Rhodomonas salina CCMP1319: lateral transfer of putative DNA replication machinery and a test of chromist plastid phylogeny}, journal = {Molecular Biology and Evolution}, volume = {24}, number = {8}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1832{\textendash}1842}, abstract = {Cryptophytes are a group of unicellular algae with chlorophyll c-containing plastids derived from the uptake of a secondary (i.e., eukaryotic) endosymbiont. Biochemical and molecular data indicate that cryptophyte plastids are derived from red algae, yet the question of whether or not cryptophytes acquired their red algal plastids independent of those in heterokont, haptophyte, and dinoflagellate algae is of long-standing debate. To better understand the origin and evolution of the cryptophyte plastid, we have sequenced the plastid genome of Rhodomonas salina CCMP1319: at 135,854 bp, it is the largest secondary plastid genome characterized thus far. It also possesses interesting features not seen in the distantly related cryptophyte Guillardia theta or in other red secondary plastids, including pseudogenes, introns, and a bacterial-derived gene for the tau/gamma subunit of DNA polymerase III (dnaX), the first time putative DNA replication machinery has been found encoded in any plastid genome. Phylogenetic analyses indicate that dnaX was acquired by lateral gene transfer (LGT) in an ancestor of Rhodomonas, most likely from a firmicute bacterium. A phylogenomic survey revealed no additional cases of LGT, beyond a noncyanobacterial type rpl36 gene similar to that recently characterized in other cryptophytes and haptophytes. Rigorous concatenated analysis of 45 proteins encoded in 15 complete plastid genomes produced trees in which the heterokont, haptophyte, and cryptophyte (i.e., chromist) plastids were monophyletic, and heterokonts and haptophytes were each other{\textquoteright}s closest relatives. However, statistical support for chromist monophyly disappears when amino acids are recoded according to their chemical properties in order to minimize the impact of composition bias, and a significant fraction of the concatenate appears consistent with a sister-group relationship between cryptophyte and haptophyte plastids.}, keywords = {*DNA Replication, *Gene Transfer, *Genome, Bacteria/*genetics, Cryptophyta/*genetics, DNA, evolution, genes, Horizontal, Molecular, phylogeny, Plant, Plastids/*genetics, rcc, Sequence Analysis, symbiosis}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=17522086}, author = {Khan, H and Parks, N and Kozera, C and Curtis, B A and Parsons, B J and Bowman, S and Archibald, J M} } @article {Piganeau2007, title = {Screening the Sargasso Sea metagenome for data to investigate genome evolution in Ostreococcus (Prasinophyceae, Chlorophyta)}, journal = {Gene}, volume = {406}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {184{\textendash}190}, abstract = {The Sargasso Sea water shotgun sequencing unveiled an unprecedented glimpse of marine prokaryotic diversity and gene content. The sequence data was gathered from 0.8 ??m filtered surface water extracts, and revealed picoeukaryotic (cell size {\textexclamdown} 2 ??m) sequences alongside the prokaryotic data. We used the available genome sequence of the picoeukaryote Ostreococcus tauri (Prasinophyceae, Chlorophyta) as a benchmark for the eukaryotic sequence content of the Sargasso Sea metagenome. Sequence data from at least two new Ostreococcus strains were identified and analyzed, and showed a bias towards higher coverage of the AT-rich organellar genomes. The Ostreococcus nuclear sequence data retrieved from the Sargasso metagenome is divided onto 731 scaffolds of average size 3917 bp, and covers 23\% of the complete nuclear genome and 14\% of the total number of protein coding genes in O. tauri. We used this environmental Ostreococcus sequence data to estimate the level of constraint on intronic and intergenic sequences in this compact genome.}, keywords = {rcc}, doi = {10.1016/j.gene.2007.09.015}, author = {Piganeau, G and Moreau, H} } @article {Medlin2007, title = {A taxonomic review of the genus Phaeocystis}, journal = {Biogeochemistry}, volume = {83}, number = {1-3}, year = {2007}, note = {ISBN: 0085-4417 tex.mendeley-tags: rcc3541}, pages = {3{\textendash}18}, abstract = {Phaeocystis is recognized both as a nuisance and as an ecologicallyphytoplankton species. Its polymorphic life cycle with bothand flagellated cells causes many taxonomic problems. Sequenceamong 22 isolates representing a global distribution of thehas been compared using three molecular markers. The-1,5-bisphosphate carboxylase/oxygenase (RUBISCO) spacer is tooto resolve species. The most conserved 18S ribosomalacid (rDNA) analysis suggests that an undescribedPhaeocystis sp. (isolate PLY559) is a sister taxon to theunicellular Phaeocystis jahnii; this clade branched priorthe divergence of all other Phaeocystis species, including theones. The internal transcribed spacer (ITS) region showsvariation that some spatial population structure can be, at least in P. antarctica. P. globosa and P. pouchetii havedifferent ITS copies, suggestive of cryptic species that areable to hybridize. A molecular clock has been constructed thatthe divergence of the cold water colonial forms from the-water colonial forms to be about 30 Ma and the divergence of P.and P. pouchetii to be about 15 Ma. A short description ofcolonial stage and the flagellated stage for each formallyspecies is provided. Morphological information is alsoon a number of undescribed species. These include the strain559, consisting of non-colonial cells with peculiar tubular, a second non-colonial species from the north westernSea producing a lot of mucus, and a colonial species with-less flagellates found in Italian waters. In addition, threemorphotypes with scales different from those of P.were reported in the literature from Antarctic waters. Theemerging from both molecular and morphological data is that theof species in the genus is still underestimated and that crypticpseudocryptic diversity requires a sound assessment in futureof this genus. Based on all published observations, an emendedof the genus is provided.}, keywords = {Molecular clock, P. cordata, P. globosa, P. jahnii, P. pouchetii, P. scrobiculata, Phaeocystis antarctica, rcc3541, rDNA analysis}, issn = {01682563}, doi = {10.1007/s10533-007-9087-1}, author = {Medlin, Linda and Zingone, Adriana} } @article {Palenik2007, title = {The tiny eukaryote \textit{Ostreococcus provides genomic insights into the paradox of plankton speciation}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {104}, number = {18}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {7705{\textendash}7710}, abstract = {The smallest known eukaryotes, at approximately 1-mum diameter, are Ostreococcus tauri and related species of marine phytoplankton. The genome of Ostreococcus lucimarinus has been completed and compared with that of O. tauri. This comparison reveals surprising differences across orthologous chromosomes in the two species from highly syntenic chromosomes in most cases to chromosomes with almost no similarity. Species divergence in these phytoplankton is occurring through multiple mechanisms acting differently on different chromosomes and likely including acquisition of new genes through horizontal gene transfer. We speculate that this latter process may be involved in altering the cell-surface characteristics of each species. In addition, the genome of O. lucimarinus provides insights into the unique metal metabolism of these organisms, which are predicted to have a large number of selenocysteine-containing proteins. Selenoenzymes are more catalytically active than similar enzymes lacking selenium, and thus the cell may require less of that protein. As reported here, selenoenzymes, novel fusion proteins, and loss of some major protein families including ones associated with chromatin are likely important adaptations for achieving a small cell size.}, keywords = {rcc}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=17460045}, author = {Palenik, B and Grimwood, J and Aerts, A and Rouz{\'e}, P and Salamov, A and Putnam, N and Dupont, C and Jorgensen, R and Derelle, E and Rombauts, S and Zhou, K and Otillar, R and Merchant, S S and Podell, S and Gaasterland, T and Napoli, C and Gendler, K and Manuell, A and Tai, V and Vallon, O and Piganeau, G and Jancek, S and Heijde, M and Jabbari, K and Bowler, C and Lohr, M and Robbens, S and Werner, G and Dubchak, I and Pazour, G J and Ren, Q and Paulsen, I and Delwiche, C and Schmutz, J and Rokhsar, D and Van de Peer, Y and Moreau, H and Grigoriev, I V} } @article {Countway2006, title = {Abundance and distribution of Ostreococcus sp in the San Pedro Channel, California, as revealed by quantitative PCR}, journal = {Applied and Environmental Microbiology}, volume = {72}, number = {4}, year = {2006}, note = {tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {2496{\textendash}2506}, abstract = {Ostreococcus is a genus of widely distributed marine phytoplankton which are picoplanktonic in size ({\textexclamdown} 2 mu m) and capable of rapid growth. Although Ostreococcus has been detected around the world, little quantitative information exists on its contribution to planktonic communities. We designed and implemented a genus-specific TaqMan-based quantitative PCR (qPCR) assay to investigate the dynamics and ecology of Ostreococcus at the USC Microbial Observatory (eastern North Pacific). Samples were collected from 5 m and the deep chlorophyll maximum (DCM) between September 2000 and August 2002. Ostreococcus abundance at 5 m was generally {\textexclamdown} 5.0 X 10(3) cells ml(-1), with a maximum of 8.2 X 10(4) cells ml(-1). Ostreococcus abundance was typically higher at the DCM, with a maximum of 3.2 X 10(5) cells ml(-1). The vertical distribution of Ostreococcus was examined in March 2005 and compared to the distribution of phototrophic picoeukaryotes (PPE) measured by flow cytometry. The largest contribution to PPE abundance by Ostreococcus was similar to 70\% and occurred at 30 m, near the DCM. Despite its relatively low abundance, the depth-integrated standing stock of Ostreococcus in March 2005 was similar to 30 mg C m(-2). Our work provides a new technique for quantifying the abundance of Ostreococcus and demonstrates the seasonal dynamics of this genus and its contribution to picoeukaryote biomass at our coastal sampling station.}, keywords = {16s-ribosomal-rna, Biology-, english-channel, eukaryotic-picoplankton, in-situ-hybridization, marine-ecosystems, microbial-populations, microbiology-, Micromonas, pfiesteria-piscicida, rcc, Real-time-pcr, sp-nov, tauri-chlorophyta}, doi = {10.1128/AEM.72.4.2496-2506.2006}, author = {Countway, P D and Caron, D A} } @article {Fuller2006, title = {Analysis of photosynthetic picoeukaryote diversity at open ocean sites in the Arabian Sea using a PCR biased towards marine algal plastids}, journal = {Aquatic Microbial Ecology}, volume = {43}, year = {2006}, note = {tex.mendeley-tags: 2006,rcc,sbr?hyto$_\textrmd$ipo}, pages = {79{\textendash}93}, keywords = {2006, PICOCEAN, PICODIV, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo}, doi = {10.3354/ame043079}, author = {Fuller, Nicholas J and Campbell, Colin and Allen, David J and Pitt, Frances D and Le Gall, F and Vaulot, Daniel and Scanlan, David J} } @article {Everroad2006, title = {Biochemical bases of Type IV chromatic adaptation in marine Synechococcus spp.}, journal = {Journal of Bacteriology}, volume = {188}, year = {2006}, note = {tex.mendeley-tags: 2006,rcc,sbr?hyto?app}, pages = {3345{\textendash}3356}, keywords = {2006, rcc, SBR$_\textrmP$hyto, sbr?hyto?app}, doi = {10.1128/JB.188.9.3345-3356.2006}, author = {Everroad, C and Six, C and Partensky, F and Thomas, J C and Holtzendorff, J and Wood, A M} } @article {Derelle2006, title = {Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {103}, number = {31}, year = {2006}, note = {tex.mendeley-tags: RCC745}, pages = {11647{\textendash}11652}, abstract = {The green lineage is reportedly 1,500 million years old, evolving shortly after the endosymbiosis event that gave rise to early photosynthetic eukaryotes. In this study, we unveil the complete genome sequence of an ancient member of this lineage, the unicellular green alga Ostreococcus tauri (Prasinophyceae). This cosmopolitan marine primary producer is the world{\textquoteright}s smallest free-living eukaryote known to date. Features likely reflecting optimization of environmentally relevant pathways, including resource acquisition, unusual photosynthesis apparatus, and genes potentially involved in C4 photosynthesis, were observed, as was downsizing of many gene families. Overall, the 12.56-Mb nuclear genome has an extremely high gene density, in part because of extensive reduction of intergenic regions and other forms of compaction such as gene fusion. However, the genome is structurally complex. It exhibits previously unobserved levels of heterogeneity for a eukaryote. Two chromosomes differ structurally from the other eighteen. Both have a significantly biased G+C content, and, remarkably, they contain the majority of transposable elements. Many chromosome 2 genes also have unique codon usage and splicing, but phylogenetic analysis and composition do not support alien gene origin. In contrast, most chromosome 19 genes show no similarity to green lineage genes and a large number of them are specialized in cell surface processes. Taken together, the complete genome sequence, unusual features, and downsized gene families, make O. tauri an ideal model system for research on eukaryotic genome evolution, including chromosome specialization and green lineage ancestry.}, keywords = {rcc, RCC745, SBR$_\textrmP$hyto}, doi = {10.1073/pnas.0604795103}, url = {http://www.pnas.org/cgi/content/abstract/103/31/11647}, author = {Derelle, Evelyne and Ferraz, Conchita and Rombauts, Stephane and Rouze, Pierre and Worden, Alexandra Z and Robbens, Steven and Partensky, Fr{\'e}d{\'e}ric and Degroeve, Sven and Echeynie, Sophie and Cooke, Richard and Saeys, Yvan and Wuyts, Jan and Jabbari, Kamel and Bowler, Chris and Panaud, Olivier and Piegu, Benoit and Ball, Steven G and Ral, Jean-Philippe and Bouget, Fran{\c c}ois-Yves and Piganeau, Gwenael and De Baets, Bernard and Picard, Andr{\'e} and Delseny, Michel and Demaille, Jacques and Van de Peer, Yves and Moreau, Herv{\'e}} } @article {Palenik2006, title = {Genome sequence of Synechococcus CC9311: Insights into adaptation to a coastal environment}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {103}, number = {36}, year = {2006}, note = {tex.mendeley-tags: RCC,rcc}, pages = {13555{\textendash}13559}, abstract = {Coastal aquatic environments are typically more highly productive and dynamic than open ocean ones. Despite these differences, cyanobacteria from the genus Synechococcus are important primary producers in both types of ecosystems. We have found that the genome of a coastal cyanobacterium, Synechococcus sp. strain CC9311, has significant differences from an open ocean strain, Synechococcus sp. strain WH8102, and these are consistent with the differences between their respective environments. CC9311 has a greater capacity to sense and respond to changes in its (coastal) environment. It has a much larger capacity to transport, store, use, or export metals, especially iron and copper. In contrast, phosphate acquisition seems less important, consistent with the higher concentration of phosphate in coastal environments. CC9311 is predicted to have differences in its outer membrane lipopolysaccharide, and this may be characteristic of the speciation of some cyanobacterial groups. In addition, the types of potentially horizontally transferred genes are markedly different between the coastal and open ocean genomes and suggest a more prominent role for phages in horizontal gene transfer in oligotrophic environments.}, keywords = {rcc}, doi = {10.1073/pnas.0602963103}, url = {http://www.pnas.org/cgi/content/abstract/103/36/13555}, author = {Palenik, Brian and Ren, Qinghu and Dupont, Chris L and Myers, Garry S and Heidelberg, John F and Badger, Jonathan H and Madupu, Ramana and Nelson, William C and Brinkac, Lauren M and Dodson, Robert J and Durkin, A Scott and Daugherty, Sean C and Sullivan, Stephen A and Khouri, Hoda and Mohamoud, Yasmin and Halpin, Rebecca and Paulsen, Ian T} } @article {palenik_genome_2006, title = {Genome sequence of Synechococcus CC9311: Insights into adaptation to a coastal environment}, journal = {Proceedings of the National Academy of Sciences}, volume = {103}, number = {36}, year = {2006}, note = {Publisher: National Academy of Sciences Section: Biological Sciences}, pages = {13555{\textendash}13559}, abstract = {Coastal aquatic environments are typically more highly productive and dynamic than open ocean ones. Despite these differences, cyanobacteria from the genus Synechococcus are important primary producers in both types of ecosystems. We have found that the genome of a coastal cyanobacterium, Synechococcus sp. strain CC9311, has significant differences from an open ocean strain, Synechococcus sp. strain WH8102, and these are consistent with the differences between their respective environments. CC9311 has a greater capacity to sense and respond to changes in its (coastal) environment. It has a much larger capacity to transport, store, use, or export metals, especially iron and copper. In contrast, phosphate acquisition seems less important, consistent with the higher concentration of phosphate in coastal environments. CC9311 is predicted to have differences in its outer membrane lipopolysaccharide, and this may be characteristic of the speciation of some cyanobacterial groups. In addition, the types of potentially horizontally transferred genes are markedly different between the coastal and open ocean genomes and suggest a more prominent role for phages in horizontal gene transfer in oligotrophic environments.}, keywords = {cyanobacteria, genomics, Marine, RCC1086}, issn = {0027-8424, 1091-6490}, doi = {10.1073/pnas.0602963103}, url = {https://www.pnas.org/content/103/36/13555}, author = {Palenik, Brian and Ren, Qinghu and Dupont, Chris L. and Myers, Garry S. and Heidelberg, John F. and Badger, Jonathan H. and Madupu, Ramana and Nelson, William C. and Brinkac, Lauren M. and Dodson, Robert J. and Durkin, A. Scott and Daugherty, Sean C. and Sullivan, Stephen A. and Khouri, Hoda and Mohamoud, Yasmin and Halpin, Rebecca and Paulsen, Ian T.} } @article {Slapeta2006, title = {Global dispersal and ancient cryptic species in the smallest marine eukaryotes}, journal = {Molecular Biology and Evolution}, volume = {23}, number = {1}, year = {2006}, note = {tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {23{\textendash}29}, abstract = {Small eukaryotic species ({\textexclamdown}1 mm) are thought to behave as prokaryotes in that, lacking geographical barriers to their dispersal due to their tiny size, they are ubiquitous. Accordingly, the absence of geographical insulation would imply the existence of a relatively small number of microeukaryotic species. To test these ideas, we sequenced and compared several nuclear, mitochondrial, and chloroplast genes from the isolates of a marine picoeukaryotic alga ([\~]2 microm), Micromonas pusilla, collected worldwide. Independent and combined phylogenetic analyses demonstrate that this traditional single morphospecies actually comprises several independent lineages, some of which are shown to be ubiquitous in oceans. However, while some lineages group closely related strains, others form distant clusters, revealing the existence of cryptic species. Moreover, molecular dating using a relaxed clock suggests that their first diversification may have started as early as during the Late Cretaceous ([\~]65 MYA), implying that "M. pusilla" is the oldest group of cryptic species known to date. Our results illustrate that global dispersal of a picoeukaryote is possible in oceans, but this does not imply a reduced species number. On the contrary, we show that the morphospecies concept is untenable because it overlooks a large genetic and species diversity and may lead to incorrect biological assumptions.}, keywords = {Micromonas, rcc}, doi = {10.1093/molbev/msj001}, url = {http://mbe.oxfordjournals.org/cgi/content/abstract/23/1/23}, author = {Slapeta, Jan and L{\'o}pez-Garc{\'\i}a, P and Moreira, David} } @article {Farinas2006, title = {Natural synchronisation for the study of cell division in the green unicellular alga Ostreococcus tauri}, journal = {Plant Molecular Biology}, volume = {60}, number = {2}, year = {2006}, note = {tex.mendeley-tags: RCC745}, pages = {277{\textendash}292}, abstract = {Ostreococcus tauri (Prasinophyceae) is a marine unicellular green alga which diverged early in the green lineage. The interest of O. tauri as a potential model to study plant cell division is based on its key phylogenetic position, its simple binary division, a very simple cellular organisation and now the availability of the full genome sequence. In addition O. tauri has a minimal yet complete set of cell cycle control genes. Here we show that division can be naturally synchronised by light/dark cycles and that organelles divide before the nucleus. This natural synchronisation, although being only partial, enables the study of the expression of CDKs throughout the cell cycle. The expression patterns of OtCDKA and OtCDKB were determined both at the mRNA and protein levels. The single OtCDKA gene is constantly expressed throughout the cell cycle, whereas OtCDKB is highly regulated and expressed only in S/G2/M phases. More surprisingly, OtCDKA is not phosphorylated at the tyrosine residue, in contrast to OtCDKB which is strongly phosphorylated during cell division. OtCDKA kinase activity appears before the S phase, indicating a possible role of this protein in the G1/S transition. OtCDKB kinase activity occurs later than OtCDKA, and its tyrosine phosphorylation is correlated to G2/M, suggesting a possible control of the mitotic activity. To our knowledge this is the first organism in the green lineage which showed CDKB tyrosine phosphorylation during cell cycle progression.}, keywords = {Cyclin-dependent kinases, Green alga, Histone H1 kinase activity, Ostreococcus tauri, Phosphorylation, RCC745, Synchronisation of the cell division}, issn = {01674412}, doi = {10.1007/s11103-005-4066-1}, author = {Farinas, Beno{\^\i}t and Mary, Camille and De O Manes, Carmem Lara and Bhaud, Yvonne and Peaucellier, G{\'e}rard and Moreau, Herv{\'e}} } @article {Worden2006, title = {Picoeukaryote diversity in coastal waters of the Pacific Ocean}, journal = {Aquatic Microbial Ecology}, volume = {43}, number = {2}, year = {2006}, note = {tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {165{\textendash}175}, abstract = {The extraordinary molecular phylogenetic diversity of picoeukaryotes and their contributions to marine processes have been highlighted recently. Herein, picoeukaryotic diversity in the coastal Pacific Ocean is characterized for the first time, Close to full length small subunit ribosomal RNA (ssu rRNA) gene amplicons were cloned and sequenced from size fractionated samples ({\textexclamdown} 2 mu m) taken between September 2000 and October 2001. Sequences belonging to the order Mamiellales were abundant, with Micromonas pusilla-like sequences in all 5 libraries (4 operational taxonomic units, OTUs, at {\textquestiondown}= 99\% sequence similarity), Ostreococcus in 4 (1 OTU) and Bathycoccus in 2 (1 OTU). Phylogenetic reconstruction showed distinct Micromonas clades at this site (although not for other Mamiellales), supporting the idea that the designation M pusilla harbors cryptic species. In combination with picophytoplankton dynamics previously reported for the same period, the data indicates that picoplanktonic primary production at this site is likely to be dominated by prasinophytes. Furthermore, a Micromonas-clade with no cultured representatives was identified bearing highest identity to Sargasso Sea shotgun clone sequences. Comparison of the Pacific sequences with the shotgun clones showed Ostreococcus and Micromonas at 1 Sargasso site with elevated chlorophyll (chl) levels, but not at other Sargasso sites. Other Pacific clones were primarily Novel Alveolate Group II, which were highly diverse based on OTU analyses. Novel Alveolate Group 1, Ciliophora, Cercozoa-like and stramenopile sequences were also retrieved. Although picoeukaryotic diversity has been characterized in only 1 other Pacific Ocean sample (equatorial Pacific), most stramenopile and alveolate sequences corresponded to previously identified phylogenetic clades from studies conducted in other oceans and for which no cultured representatives exist.}, keywords = {18s rdna sequences, 18S rRNA, community structure, diversity, english-channel, eukaryotic picoplankton, global dispersal, Micromonas, north-atlantic, phylogenetic analysis, picoeukaryotes, picophytoplankton, picoplankton, prasinophytes, pusilla, rcc, RIBOSOMAL-RNA GENE, sargasso sea, small subunit, vibrio-cholerae}, doi = {10.3354/ame043165}, author = {Worden, A Z} } @article {Sandaa2006, title = {Seasonal variations in virus-host populations in norwegian coastal waters: Focusing on the cyanophage community infecting marine synechococcus spp.}, journal = {Applied and Environmental Microbiology}, volume = {72}, number = {7}, year = {2006}, note = {ISBN: 0099-2240 tex.mendeley-tags: RCC2035}, month = {jul}, pages = {4610{\textendash}4618}, abstract = {Viruses are ubiquitous components of the marine ecosystem. In the current study we investigated seasonal variations in the viral community in Norwegian coastal waters by pulsed-field gel electrophoresis (PFGE). The results demonstrated that the viral community was diverse, displaying dynamic seasonal variation, and that viral populations of 29 different sizes in the range from 26 to 500 kb were present. Virus populations from 260 to 500 kb and dominating autotrophic pico- and nanoeukaryotes showed similar dynamic variations. Using flow cytometry and real-time PCR, we focused in particular on one host-virus system: Synechococcus spp. and cyanophages. The two groups covaried throughout the year and were found in the highest amounts in fall with concentrations of 7.3 x 10(4) Synechococcus cells ml(-1) and 7.2 x 10(3) cyanophage ml(-1). By using primers targeting the g20 gene in PCRs on DNA extracted from PFGE bands, we demonstrated that cyanophages were found in a genomic size range of 26 to 380 kb. The genetic richness of the cyanophage community, determined by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified g20 gene fragments, revealed seasonal shifts in the populations, with one community dominating in spring and summer and a different one dominating in fall. Phylogenetic analysis of the sequences originating from PFGE and DGGE bands grouped the sequences into three groups, all with homology to cyanomyoviruses present in cultures. Our results show that the cyanophage community in Norwegian coastal waters is dynamic and genetically diverse and has a surprisingly wide genomic size range.}, keywords = {RCC2035}, issn = {0099-2240}, doi = {10.1128/AEM.00168-06}, url = {http://aem.asm.org/cgi/doi/10.1128/AEM.00168-06}, author = {Sandaa, R.-A. and Larsen, Aud} } @article {Bruyant2005, title = {Diel variations in the photosynthetic parameters of Prochlorococcus strain PCC 9511: combined effects of light and cell cycle}, journal = {Limnology and Oceanography}, volume = {50}, year = {2005}, note = {tex.mendeley-tags: 2005,rcc,sbr?hyto}, pages = {850{\textendash}863}, keywords = {2005, rcc, SBR$_\textrmP$hyto, sbr?hyto}, doi = {10.4319/lo.2005.50.3.0850}, author = {Bruyant, F and Babin, M and Genty, B and Prasil, O and Behrenfeld, M J and Claustre, H and Bricaud, A and Holtzendorff, J and Koblizek, M and Garczareck, L and Partensky, F} } @article {Rodriguez2005h, title = {Ecotype diversity in the marine picoeukaryote Ostreococcus (Chlorophyta, Prasinophyceae).}, journal = {Environmental Microbiology}, volume = {7}, year = {2005}, note = {tex.mendeley-tags: RCC113,RCC143,RCC343,RCC356,RCC371,RCC393,RCC410,RCC420,RCC434,RCC501,RCC658,RCC745,Rcc141}, pages = {853{\textendash}859}, keywords = {rcc, RCC113, Rcc141, RCC143, RCC343, RCC356, RCC371, RCC393, rcc410, RCC420, RCC434, rcc501, RCC658, RCC745, SBR$_\textrmP$hyto$_\textrmD$PO}, doi = {10.1111/j.1462-2920.2005.00758.x}, author = {Rodriguez, F and Derelle, E and Guillou, L and Le Gall, F and Vaulot, D and Moreau, H} } @article {Robbens2005, title = {Genome-wide analysis of core cell cycle genes in the unicellular green alga Ostreococcus tauri}, journal = {Molecular Biology and Evolution}, volume = {22}, number = {3}, year = {2005}, note = {tex.mendeley-tags: RCC745}, pages = {589{\textendash}597}, abstract = {The cell cycle has been extensively studied in various organisms, and the recent access to an overwhelming amount of genomic data has given birth to a new integrated approach called comparative genomics. Comparing the cell cycle across species shows that its regulation is evolutionarily conserved; the best-known example is the pivotal role of cyclin-dependent kinases in all the eukaryotic lineages hitherto investigated. Interestingly, the molecular network associated with the activity of the CDK-cyclin complexes is also evolutionarily conserved, thus, defining a core cell cycle set of genes together with lineage-specific adaptations. In this paper, we describe the core cell cycle genes of Ostreococcus tauri, the smallest free-living eukaryotic cell having a minimal cellular organization with a nucleus, a single chloroplast, and only one mitochondrion. This unicellular marine green alga, which has diverged at the base of the green lineage, shows the minimal yet complete set of core cell cycle genes described to date. It has only one homolog of CDKA, CDKB, CDKD, cyclin A, cyclin B, cyclin D, cyclin H, Cks, Rb, E2F, DP, DEL, Cdc25, and Wee L We have also added the APC and SCF E3 ligases to the core cell cycle gene set. We discuss the potential of genome-wide analysis in the identification of divergent orthologs of cell cycle genes in different lineages by mining the genomes of evolutionarily important and strategic organisms.}, keywords = {Anaphase Promoting Complex, Arabidopsis Thaliana, Cdk Activity, cell division cycle, Chlorophyta, cyclin, cyclin dependant kinase, Green alga, Kinase, Ostreococcus tauri, Plant, Prasinophyceae, rcc, RCC745, Retinoblastoma Protein, Saccharomyces Cerevisiae, Yeast}, doi = {10.1093/molbev/msi044}, author = {Robbens, S and Khadaroo, B and Camasses, A and Derelle, E and Ferraz, C and Inze, D and Van, de Peer Y and Moreau, H} } @article {Zhu2005, title = {Mapping of picoeucaryotes in marine ecosystems with quantitative PCR of the 18S rRNA gene}, journal = {FEMS Microbiology Ecology}, volume = {52}, number = {1}, year = {2005}, note = {tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {79{\textendash}92}, abstract = {A quantitative PCR (QPCR) assay based on the use of SYBR Green I was developed to assess the abundance of specific groups of picoeukaryotes in marine waters. Six primer sets were designed targeting four different taxonomic levels: domain (Eukaryota), division (Chlorophyta), order (Mamiellales) and genus (Bathycoccus, Micromonas, and Ostreococcus). Reaction conditions were optimized for each primer set which was validated in silico, on agarose gels, and by QPCR against a variety of target and non-target cultures. The approach was tested by estimating gene copy numbers for Micromonas, Bathycoccus, and Ostreococcus in seawater samples to which cultured cells were added in various concentrations. QPCR was then used to determine that rRNA gene (rDNA) copy number varied from one to more than 12,000 in 18 strains of phytoplankton. Finally, QPCR was applied to environmental samples from a Mediterranean Sea coastal site and the results were compared to those obtained by Fluorescent in situ hybridization (FISH). The data obtained demonstrate that Chlorophyta and more specifically Mamiellales were important in these waters, especially during the winter picoplankton bloom. The timing of major abundance peaks of the targeted species was similar by QPCR and FISH. When used in conjunction with other techniques such as FISH or gene clone libraries, QPCR appears as very promising to quickly obtain data on the ecological distribution of important phytoplankton groups. Data interpretation must take into account primer specificity and the varying rRNA gene copy number among eukaryotes. ?? 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.}, keywords = {Coastal ecosystems, Ecology, Fluorescent in situ hybridization, Micromonas, picoplankton, prasinophytes, Quantitative PCR, rcc}, author = {Zhu, Fei and Massana, Ramon and Not, Fabrice and Marie, Dominique and Vaulot, Daniel} } @article {Six2005a, title = {New insights into the nature and phylogeny of prasinophyte antenna proteins: Ostreococcus tauri, a case study}, journal = {Molecular Biology and Evolution}, volume = {22}, number = {11}, year = {2005}, note = {tex.mendeley-tags: RCC113,RCC114,RCC745: RCC417}, pages = {2217{\textendash}2230}, abstract = {The basal position of the Mamiellales (Prasinophyceae) within the green lineage makes these unicellular organisms key to elucidating early stages in the evolution of chlorophyll a/b{\textendash}binding light-harvesting complexes (LHCs). Here, we unveil the complete and unexpected diversity of Lhc proteins in Ostreococcus tauri, a member of the Mamiellales order, based on results from complete genome sequencing. Like Mantoniella squamata, O. tauri possesses a number of genes encoding an unusual prasinophyte-specific Lhc protein type herein designated "Lhcp". Biochemical characterization of the complexes revealed that these polypeptides, which bind chlorophylls a, b, and a chlorophyll c{\textendash}like pigment (Mg-2,4-divinyl-phaeoporphyrin a5 monomethyl ester) as well as a number of unusual carotenoids, are likely predominant. They are retrieved to some extent in both reaction center I (RCI){\textendash} and RCII-enriched fractions, suggesting a possible association to both photosystems. However, in sharp contrast to previous reports on LHCs of M. squamata, O. tauri also possesses other LHC subpopulations, including LHCI proteins (encoded by five distinct Lhca genes) and the minor LHCII polypeptides, CP26 and CP29. Using an antibody against plant Lhca2, we unambiguously show that LHCI proteins are present not only in O. tauri, in which they are likely associated to RCI, but also in other Mamiellales, including M. squamata. With the exception of Lhcp genes, all the identified Lhc genes are present in single copy only. Overall, the discovery of LHCI proteins in these prasinophytes, combined with the lack of the major LHCII polypeptides found in higher plants or other green algae, supports the hypothesis that the latter proteins appeared subsequent to LHCI proteins. The major LHC of prasinophytes might have arisen prior to the LHCII of other chlorophyll a/b{\textendash}containing organisms, possibly by divergence of a LHCI gene precursor. However, the discovery in O. tauri of CP26-like proteins, phylogenetically placed at the base of the major LHCII protein clades, yields new insight to the origin of these antenna proteins, which have evolved separately in higher plants and green algae. Its diverse but numerically limited suite of Lhc genes renders O. tauri an exceptional model system for future research on the evolution and function of LHC components.}, keywords = {rcc, RCC113, RCC114, RCC417, RCC745, SBR$_\textrmP$hyto$_\textrmD$PO}, doi = {10.1093/molbev/msi220}, author = {Six, C and Worden, A Z and Rodriguez, F and Moreau, H and Partensky, F} } @inbook {Marie2005, title = {Phytoplankton cell counting by flow cytometry}, booktitle = {Algal culturing techniques}, year = {2005}, note = {tex.mendeley-tags: 2005,rcc,sbr?hyto}, pages = {253{\textendash}267}, publisher = {Academic Press}, organization = {Academic Press}, keywords = {2005, PICODIV, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto}, author = {Marie, D and Simon, N and Vaulot, D}, editor = {Andersen, R A} } @article {Six2005, title = {Two novel phycoerythrin-associated linker proteins in the marine cyanobacterium synechococcus sp. Strain WH8102}, journal = {Journal of Bacteriology}, volume = {187}, number = {5}, year = {2005}, note = {tex.mendeley-tags: 2005,rcc,sbr?hyto}, pages = {1685{\textendash}1694}, abstract = {The recent availability of the whole genome of Synechococcus sp. strain WH8102 allows us to have a global view of the complex structure of the phycobilisomes of this marine picocyanobacterium. Genomic analyses revealed several new characteristics of these phycobilisomes, consisting of an allophycocyanin core and rods made of one type of phycocyanin and two types of phycoerythrins (I and II). Although the allophycocyanin appears to be similar to that found commonly in freshwater cyanobacteria, the phycocyanin is simpler since it possesses only one complete set of alpha and beta subunits and two rod-core linkers (CpcG1 and CpcG2). It is therefore probably made of a single hexameric disk per rod. In contrast, we have found two novel putative phycoerythrin-associated linker polypeptides that appear to be specific for marine Synechococcus spp. The first one (SYNW2000) is unusually long (548 residues) and apparently results from the fusion of a paralog of MpeC, a phycoerythrin II linker, and of CpeD, a phycoerythrin-I linker. The second one (SYNW1989) has a more classical size (300 residues) and is also an MpeC paralog. A biochemical analysis revealed that, like MpeC, these two novel linkers were both chromophorylated with phycourobilin. Our data suggest that they are both associated (partly or totally) with phycoerythrin II, and we propose to name SYNW2000 and SYNW1989 MpeD and MpeE, respectively. We further show that acclimation of phycobilisomes to high light leads to a dramatic reduction of MpeC, whereas the two novel linkers are not significantly affected. Models for the organization of the rods are proposed.}, keywords = {2005, rcc, SBR$_\textrmP$hyto, sbr?hyto}, doi = {10.1128/JB.187.5.1685-1694.2005}, url = {http://jb.asm.org/cgi/content/abstract/187/5/1685}, author = {Six, Christophe and Thomas, Jean-Claude and Thion, Laurent and Lemoine, Yves and Zal, Frank and Partensky, Fr{\'e}d{\'e}ric} } @article {Romari2004, title = {Composition and temporal variability of picoeukaryote communities at a coastal site of the English Channel from 18S rDNA sequences}, volume = {49}, number = {3}, year = {2004}, note = {Publication Title: Limnology and oceanography ISBN: 0024-3590 tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {784{\textendash}798}, abstract = {Abstract We analyzed picoeukaryote assemblages at a French coastal site of the English Channel by sequencing cloned eukaryotic 18S rRNA genes in eight genetic libraries constructed from environmental samples (seven coastal , one estuarine) collected at different periods of the ...}, keywords = {Micromonas, rcc}, issn = {00243590}, doi = {10.4319/lo.2004.49.3.0784}, author = {Romari, Khadidja and Vaulot, Daniel} } @article {Guillou2004, title = {Diversity of picoplanktonic prasinophytes assessed by direct nuclear SSU rDNA sequencing of environmental samples and novel isolates retrieved from oceanic and coastal marine ecosystems}, journal = {Protist}, volume = {155}, year = {2004}, note = {tex.mendeley-tags: 2004,rcc,sbr?hyto}, pages = {193{\textendash}214}, keywords = {2004, PICODIV, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto, SOMLIT}, doi = {10.1078/143446104774199592}, author = {Guillou, Laure and Eikrem, W and Chr{\'e}tiennot-Dinet, M.-J. and Le Gall, F and Massana, R and Romari, K and Pedr{\'o}s-Ali{\'o}, C and Vaulot, D} } @article {Henley2004, title = {Phylogenetic analysis of the Nannochloris-like{\textquoteright} algae and diagnoses of Picochlorum oklahomensis gen. et sp nov (Trebouxiophyceae, Chlorophyta)}, journal = {Phycologia}, volume = {43}, number = {6}, year = {2004}, note = {tex.mendeley-tags: 2004,rcc,sbr?hyto}, pages = {641{\textendash}652}, abstract = {A broadly halotolerant new isolate of a small asexual coccoid chlorophyte and six new, related freshwater isolates provided the impetus for a phylogenetic analysis of the so-called {\textquoteright}Nannochloris-like{\textquoteright} algae within the Trebouxiophyceae. Previous taxonomic disagreements concerning this group had not been rigorously tested with molecular phylogenetic analyses. We show with 18S ribosomal DNA (rDNA) sequence phylogeny that 19 of 22 isolates previously assigned to either Nannochloris or Nanochlorum fall within a diverse sister clade to a clade including the four {\textquoteright}true{\textquoteright} Chlorella species sensu loto. In addition, Marvania geminata, Gloeotila contorta, Chlorella sp. Yanaqocha RA1, Koliella spiculiformis, {\textquoteright}Chlorella minutissima{\textquoteright} C-1.1.9. and new Koliella, Gloeotila and Marvania isolates were included in the Nannochloris-like clade. Distinct freshwater and marine or saline lineages comprise at least three major subclades, generally corresponding to cell division pattern. Seven of 14 marine or saline isolates are known (and the others presumed) to divide by autosporulation. Eight freshwater isolates divide by binary fission, including two Koliella, two Gloeotila, N. bacillaris, Chlorella sp. Yanaqocha RA1, and two new unassigned isolates. Four freshwater isolates divide by budding or autosporulation (three Marvania, including CCAP 251/1b. previously assigned to N. coccoides). The autosporic taxa N. eucaryotum UTEX 2502 (marine) and C. minutissima C-1.1.9 (freshwater), which have nearly identical 18S rDNA sequences, are deeper-branching than the freshwater and marine or saline lineages. We propose including the 13 marine or saline, autosporic taxa (excluding N. eucaryotum UTEX 2502) in the new genus Picochlorum until distinctive morphological or biochemical characters are identified that would indicate multiple genera corresponding to subclades. Such characters exist in the freshwater lineages, supporting retention of Koliella, Gloeotila, Marvania and Nannochloris as distinct genera, although each is currently represented by few isolates. Nannochloris at this time may be restricted to N. bacillaris and Chlorella sp. Yanaqocha RA1. We also describe halotolerant P. oklahomensis Hironaka sp. nov. Based on 18S rDNA sequence and lack of chlorophyll b, Nannochloris sp. UTEX 2379 should be reassigned to the Eustigmatophyceae.}, keywords = {18s-, 2004, Aquatic-sciences, cell-wall, chlorella-, green-alga, life-cycle, marvania-geminata, morphology-, Nanochlorum-eucaryotum, position-, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto, SEQUENCES}, doi = {10.2216/i0031-8884-43-6-641.1}, author = {Henley, W J and Hironaka, J L and Guillou, L and Buchheim, M A and Buchheim, J A and Fawley, M W and Fawley, K P} } @article {Latasa2004, title = {Pigment suites and taxonomic groups in Prasinophyceae}, journal = {Journal of Phycology}, volume = {40}, number = {6}, year = {2004}, note = {tex.mendeley-tags: 2004,rcc,sbr?hyto}, month = {dec}, pages = {1149{\textendash}1155}, keywords = {2004, PICODIV, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto}, issn = {00223646}, doi = {10.1111/j.1529-8817.2004.03136.x}, url = {http://doi.wiley.com/10.1111/j.1529-8817.2004.03136.x}, author = {Latasa, Mikel and Scharek, Renate and Gall, Florence Le and Guillou, Laure and Le Gall, F} } @article {Vaulot2004, title = {The roscoff culture collection (RCC): a collection dedicated to marine picoplankton}, journal = {Nova Hedwigia}, volume = {79}, number = {1/2}, year = {2004}, note = {tex.mendeley-tags: 2004,rcc,sbr?hyto}, pages = {49{\textendash}70}, keywords = {10$_\textrmb$est, 2004, PICODIV, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto}, doi = {10.1127/0029-5035/2004/0079-0049}, author = {Vaulot, D and Le Gall, F and Marie, D and Guillou, L and Partensky, F} } @article {Ral2004, title = {Starch division and partitioning. A mechanism for granule propagation and maintenance in the picophytoplanktonic green alga Ostreococcus tauri}, journal = {Plant Physiology}, volume = {136}, number = {2}, year = {2004}, note = {tex.mendeley-tags: RCC745}, pages = {3333{\textendash}3340}, abstract = {Whereas Glc is stored in small-sized hydrosoluble glycogen particles in archaea, eubacteria, fungi, and animal cells, photosynthetic eukaryotes have resorted to building starch, which is composed of several distinct polysaccharide fractions packed into a highly organized semicrystalline granule. In plants, both the initiation of polysaccharide synthesis and the nucleation mechanism leading to formation of new starch granules are currently not understood. Ostreococcus tauri, a unicellular green alga of the Prasinophyceae family, defines the tiniest eukaryote with one of the smallest genomes. We show that it accumulates a single starch granule at the chloroplast center by using the same pathway as higher plants. At the time of plastid division, we observe elongation of the starch and division into two daughter structures that are partitioned in each newly formed chloroplast. These observations suggest that in this system the information required to initiate crystalline polysaccharide growth of a new granule is contained within the preexisting polysaccharide structure and the design of the plastid division machinery.}, keywords = {Adp Glucose Pyrophosphorylase, Amylopectin, Arabidopsis, Bacterial Glycogen, Biogenesis, Biosynthesis, Chlamydomonas Reinhardtii, Enzyme, Prasinophyceae, rcc, RCC745, Synthase}, doi = {10.1104/pp.104.044131}, author = {Ral, J P and Derelle, E and Ferraz, C and Wattebled, F and Farinas, B and Corellou, F and Buleon, A and Slomianny, M C and Delvalle, D and D, Hulst C and Rombauts, S and Moreau, H and Ball, S} } @article {Fuller2003, title = {Clade-specific 16S ribosomal DNA oligonucleotides reveal the predominance of a single marine Synechococcus clade throughout a stratified water column in the Red Sea}, journal = {Applied and Environmental Microbiology}, volume = {69}, number = {5}, year = {2003}, note = {tex.mendeley-tags: 2003,rcc,sbr?hyto}, pages = {2430{\textendash}2443}, abstract = {Phylogenetic relationships among members of the marine Synechococcus genus were determined following sequencing of the 16S ribosomal DNA (rDNA) from 31 novel cultured isolates from the Red Sea and several other oceanic environments. This revealed a large genetic diversity within the marine Synechococcus cluster consistent with earlier work but also identified three novel clades not previously recognized. Phylogenetic analyses showed one clade, containing halotolerant isolates lacking phycoerythrin (PE) and including strains capable, or not, of utilizing nitrate as the sole N source, which clustered within the MC-A (Synechococcus subcluster 5.1) lineage. Two copies of the 16S rRNA gene are present in marine Synechococcus genomes, and cloning and sequencing of these copies from Synechococcus sp. strain WH 7803 and genomic information from Synechococcus sp. strain WH 8102 reveal these to be identical. Based on the 16S rDNA sequence information, clade-specific oligonucleotides for the marine Synechococcus genus were designed and their specificity was optimized. Using dot blot hybridization technology, these probes were used to determine the in situ community structure of marine Synechococcus populations in the Red Sea at the time of a Synechococcus maximum during April 1999. A predominance of genotypes representative of a single clade was found, and these genotypes were common among strains isolated into culture. Conversely, strains lacking PE, which were also relatively easily isolated into culture, represented only a minor component of the Synechococcus population. Genotypes corresponding to well-studied laboratory strains also appeared to be poorly represented in this stratified water column in the Red Sea.}, keywords = {2003, PICODIV, rcc, SBR$_\textrmP$hyto, sbr?hyto}, issn = {0099-2240}, doi = {10.1128/AEM.69.5.2430-2443.2003}, url = {http://aem.asm.org/cgi/content/abstract/69/5/2430}, author = {Fuller, Nicholas J and Marie, Dominique and Partensky, Fr{\'e}d{\'e}ric and Vaulot, Daniel and Post, Anton F and Scanlan, David J} } @article {Palenik2003, title = {The genome of a motile marine Synechococcus}, journal = {Nature}, volume = {424}, number = {6952}, year = {2003}, note = {tex.mendeley-tags: 2003,rcc,sbr?hyto}, pages = {1037{\textendash}1042}, abstract = {Marine unicellular cyanobacteria are responsible for an estimated 20-40\% of chlorophyll biomass and carbon fixation in the oceans(1). Here we have sequenced and analysed the 2.4-megabase genome of Synechococcus sp. strain WH8102, revealing some of the ways that these organisms have adapted to their largely oligotrophic environment. WH8102 uses organic nitrogen and phosphorus sources and more sodium-dependent transporters than a model freshwater cyanobacterium. Furthermore, it seems to have adopted strategies for conserving limited iron stores by using nickel and cobalt in some enzymes, has reduced its regulatory machinery (consistent with the fact that the open ocean constitutes a far more constant and buffered environment than fresh water), and has evolved a unique type of swimming motility. The genome of WH8102 seems to have been greatly influenced by horizontal gene transfer, partially through phages. The genetic material contributed by horizontal gene transfer includes genes involved in the modification of the cell surface and in swimming motility. On the basis of its genome, WH8102 is more of a generalist than two related marine cyanobacteria(2).}, keywords = {2003, Cyanobacterium Synechococcus, Degradation, Ecology, Gene, IDENTIFICATION, Polypeptide, Prochlorococcus, rcc, SBR$_\textrmP$hyto, sbr?hyto, SEQUENCE, Sp Pcc7942, Strains}, doi = {10.1038/nature01943}, author = {Palenik, B and Brahamsha, B and Larimer, F W and Land, M and Hauser, L and Chain, P and Lamerdin, J and Regala, W and Allen, E E and McCarren, J and Paulsen, I and Dufresne, A and Partensky, F and Webb, E A and Waterbury, J} } @article {Biegala2003, title = {Quantitative assessment of picoeucaryotes in the natural environment using taxon specific oligonucleotide probes in association with TSA-FISH (Tyramide Signal Amplification - Fluorescent In Situ Hybridization) and flow cytometry}, journal = {Applied and Environmental Microbiology}, volume = {69}, year = {2003}, note = {tex.mendeley-tags: 2003,rcc,sbr?hyto}, pages = {5519{\textendash}5529}, keywords = {2003, PICODIV, rcc, SBR$_\textrmP$hyto, sbr?hyto, SOMLIT}, doi = {10.1128/AEM.69.9.5519-5529.2003}, author = {Biegala, I C and Not, F and Vaulot, D and Simon, N} } @article {Toledo2003, title = {A Synechococcus serotype is found preferentially in surface marine waters}, journal = {Limnology and Oceanography}, volume = {48}, number = {5}, year = {2003}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1744{\textendash}1755}, abstract = {In marine ecosystems, gradients of light, temperature, and nutrients occur horizontally (coastal to offshore) and vertically. The extent to which microorganisms acclimate or speciate in response to these gradients is under active investigation. Strain isolation data (e.g., site or depth), environmental DNA clone libraries, and preliminary physiology experiments have indicated that marine Synechococcus strain CC9605 might be adapted to the surface oligotrophic ocean. In the present work, we used an immunofluorescent approach to detect the CC9605 serotype in the California Current during September 1998. At two offshore stations, samples were collected along vertical profiles. The relative abundance of the CC9605 serotype was significantly higher in shallow depths within the mixed layer than in deeper depths at the two stations, with maximum values (+/- standard deviation) of 10.3\% +/- 6.4 and 28.7\% +/- 9.5. Surface samples along an offshore-inshore transect showed higher abundance in the most oligotrophic site (8\% +/- 3), compared with almost 1\% inshore, but one coastal site also had high relative abundance of the CC9605 serotype (7\% +/- 0.5). These data indicate that Synechococcus strains are not uniformly distributed and that some strains, such as CC9605, are more abundant in the mixed layer of the euphotic zone than below the mixed layer.}, keywords = {Aquatic-sciences, california-current, cyanobacteria-, diversity-, flow-cytometry, immunofluorescence-, North-atlantic-ocean, phytoplankton-, prochlorococcus-populations, rcc, sargasso-sea, strains-}, doi = {10.4319/lo.2003.48.5.1744}, author = {Toledo, G and Palenik, B} } @article {OKelly2003, title = {A transient bloom of {\textexclamdown}i{\textquestiondown}Ostreococcus{\textexclamdown}/i{\textquestiondown} (chlorophyta, prasinophyceae) in west neck bay, long island, new york}, journal = {Journal of Phycology}, volume = {39}, number = {5}, year = {2003}, note = {tex.mendeley-tags: RCC,rcc}, pages = {850{\textendash}854}, abstract = {The smallest known eukaryote, Ostreococcus tauri Courties et Chretiennot-Dinet, was first reported as the dominant picoplankter in a French lagoon known for its diverse phytoplankton community and high oyster productivity. Long-term seasonal blooms of this picoeukaryote were observed in association with stable plankton communities. On 5 June 2001, a distinctive monotypic picoplankton bloom was detected by flow cytometry as part of an ongoing study of "brown tide" (Aureococcus anophagefferens) bloom initiation in Long Island bays. The bloom reached a concentration of 5 x 10(5) cells.mL(-1) in West Neck Bay and lasted less than 2 weeks. Epifluorescence microscopy and TEM indicated that the bloom organism was an Ostreococcus-like picoalga, the first ever observed in a Long Island bay. Many cells of this alga contained numerous virus-like particles. The Ostreococcus-like picoalga, which resembles O. tauri, was rare in samples collected the following week. Instead, a substantial increase in the Synechococcus population was observed. Such rapid population changes have not previously been reported for Ostreococcus. Viral lysis and grazing by heterotrophic nanoflagellates may have contributed to the rapid decline of the Ostreococcus-like cells in West Neck Bay.}, keywords = {Aureococcus Anophagefferens Pelagophyceae, bloom dynamics, Gen, Microalga, Ostreococcus, picoalgae, picoplankton, rcc}, doi = {10.1046/j.1529-8817.2003.02201.x}, author = {O{\textquoteright}Kelly, C J and Sieracki, M E and Thier, E C and Hobson, I C} } @article {Not2002, title = {Application of fluorescent in situ hybridization coupled with tyramide signal amplification (FISH-TSA) to assess eukaryotic picoplankton composition}, volume = {28}, year = {2002}, note = {Publication Title: Aquatic microbial ecology tex.mendeley-tags: RCC,rcc}, pages = {157{\textendash}166}, abstract = {Photosynthetic picoeukaryotes (phytoplankton cells with a diameter smaller than 2 to 3 ??m) contribute significantly to both biomass and primary production in the oligotrophic open ocean and coastal waters, at certain times of the year. The identification of these organisms is difficult because of their small size and simple morphology, therefore hindering detailed ecological studies of their distribution and role. In this paper, we demonstrate the use of oligonucleotide probes specific to algal classes or to lower order taxa in combination with fluorescent in situ hybridization and tyramide signal amplification (FISH-TSA) to determine eukaryotic picophytoplankton diversity. Target cells were detected and enumerated using epifluorescence microscopy. The sensitivity of the technique and the specificity of the probes were tested on pure and mixed picoplanktonic strains, as well as on natural samples from the English Channel. In these samples, the community was dominated by cells belonging to the division Chlorophyta. Haptophyta, Bolidophyceae and Pelagophyceae were also detected at low abundance. The FISH-TSA method is readily applicable to the study of picoplankton diversity in natural communities.}, keywords = {rcc}, issn = {0948-3055}, doi = {10.3354/ame028157}, author = {Not, F and Simon, N and Biegala, IC and Vaulot, D} } @article {Derelle2002, title = {DNA libraries for sequencing the genome of Ostreococcus tauri (Chlorophyta, Prasinophyceae): The smallest free-living eukaryotic cell}, journal = {Journal of Phycology}, volume = {38}, number = {6}, year = {2002}, note = {tex.mendeley-tags: RCC745}, pages = {1150{\textendash}1156}, abstract = {Ostreococcus tauri is a marine photosynthetic picoeukaryote presenting a minimal cellular organization with one nucleus, one chloroplast, and one mitochondrion. It has the smallest genome described among free-living eukaryotic cells, and we showed by pulsed-field gel electrophoresis (PFGE) that it is divided between 15 bands ranging from 1.2 to 0.15 Mb, giving a total size of 9.7 Mb. A Bacterial Artificial Chromosome (BAC) library was prepared from genomic DNA extracted from a culture of O. tauri. A total of 2457 clones was obtained with an average insert size of around 70 kb, representing an 18-fold coverage of the genome. The library was spotted on high density filters, and several probes of coding sequences were hybridized to both the high density BAC library filters and directly to the dried PFGE gels of the O. tauri genomic DNA. These hybridizations allowed a preliminary organization of the library and the localization of several markers on the chromosomes. Randomly selected fragments were also sequenced, representing 12\% of the O. tauri genome. Many sequences showed significant similarities in data banks, mainly with plant and algae sequences. About 1000 coding sequences could be identified. These data confirmed the position of O. tauri in the green lineage and the hypothesis of a very compact organization of its genome.}, keywords = {Pico$_\textrmR$eview, rcc, RCC745}, doi = {10.1046/j.1529-8817.2002.02021.x}, url = {c:\%5CDV\%5CPapers reprints\%5CPhytoplankton Physiology\%5CDerelle Ostreococcus DNA libraries JPhycol 02.pdf}, author = {Derelle, E and Ferraz, C and Lagoda, P and Eychenie, S and Cooke, R and Regad, F and Sabau, X and Courties, C and Delseny, M and Demaille, J and Picard, A and Moreau, H} } @article {Laloui2002, title = {Genotyping of axenic and non-axenic isolates of the genus Prochlorococcus and the OMF-{\textquoteright}Synechococcus{\textquoteright} clade by size, sequence analysis or RFLP of the Internal Transcribed Spacer of the ribosomal operon}, journal = {Microbiology}, volume = {148}, number = {2}, year = {2002}, note = {tex.mendeley-tags: 2002,rcc,sbr?hyto}, pages = {453{\textendash}465}, abstract = {PCR amplicons of the Internal Transcribed Spacer (ITS) of the rrn operon of three axenic OMF (oceanic, marine and freshwater) strains of {\textquoteright}Synechococcus{\textquoteright} (wH7803, PCC 7001 and PCC 6307, respectively) differ greatly in length from that of the axenic Prochlorococcus marinus subsp. pastoris PCC 9511(T), although these four cyanobacteria cluster relatively closely in phylogenetic trees inferred from 165 rRNA gene sequences. The ITSs of three strains (PCC 9511(T), PCC 6307 and PCC 7001) were sequenced and compared with those available for strains Prochlorococcus MED4 (CCMP 1378) and MIT9313 from genome sequencing projects. In spite of large differences in length, sequence and mean DNA base composition, conserved domains important for transcriptional antitermination and folding of the rRNA transcripts were identified in all ITSs. A new group-specific primer permitted ITS amplification even with non-axenic isolates of Prochlorococcus and one OMF-{\textquoteright}Synechococcus{\textquoteright} strain. Prochlorococcus isolates of the high-light-adapted clade (HL) differed from representatives of the low-light-adapted Glade (LL) by the length of their ITS. Restriction fragment length polymorphism (RFLP) of the ITS amplicons revealed three subclusters among the HL strains. Size, sequence data and RFLP of the ITS amplicons will therefore be valuable markers for the identification of different Prochlorococcus genotypes and for their discrimination from other cyanobacterial relatives with which they often co-exist in oceanic ecosystems.}, keywords = {2002, Blue Green Alga, Chlorophyll B, community structure, cyanobacteria, Escherichia Coli, Marine Prokaryote, Multiple Evolutionary Origins, North Atlantic Ocean, Pacific Ocean, rcc, Rna Operon, SBR$_\textrmP$hyto, sbr?hyto}, doi = {10.1099/00221287-148-2-453}, author = {Laloui, W and Palinska, K A and Rippka, R and Partensky, F and de Marsac, N T and Herdman, M and Iteman, I} } @article {Rocap2002, title = {Resolution of Prochlorococcus and Synechococcus ecotypes by using 16S-23S ribosomal DNA internal transcribed spacer sequences}, journal = {Applied and Environmental Microbiology}, volume = {68}, number = {3}, year = {2002}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1180{\textendash}1191}, abstract = {Cultured isolates of the marine cyanobacteria Prochlorococcus and Synechococcus vary widely in their pigment compositions and growth responses to light and nutrients, yet show greater than 96\% identity in their 16S ribosomal DNA (rDNA) sequences. In order to better define the genetic variation that accompanies their physiological diversity, sequences for the 16S-23S rDNA internal transcribed spacer (ITS) region were determined in 32 Prochlorococcus isolates and 25 Synechococcus isolates from around the globe. Each strain examined yielded one ITS sequence that contained two tRNA genes. Dramatic variations in the length and G+C content of the spacer were observed among the strains, particularly among Prochlorococcus strains. Secondary-structure models of the ITS were predicted in order to facilitate alignment of the sequences for phylogenetic analyses. The previously observed division of Prochlorococcus into two ecotypes (called high and low-B/A after their differences in chlorophyll content) were supported, as was the subdivision of the high-B/A ecotype into four genetically distinct clades. ITS-based phylogenies partitioned marine cluster A Synechococcus into six clades, three of which can be associated with a particular phenotype (motility, chromatic adaptation, and lack of phycourobilin). The pattern of sequence divergence within and between clades is suggestive of a mode of evolution driven by adaptive sweeps and implies that each clade represents an ecologically distinct population. Furthermore, many of the clades consist of strains isolated from disparate regions of the world{\textquoteright}s oceans, implying that they are geographically widely distributed. These results provide further evidence that natural populations of Prochlorococcus and Synechococcus consist of multiple coexisting ecotypes, genetically closely related but physiologically distinct, which may vary in relative abundance with changing environmental conditions.}, keywords = {Divinyl Chlorophyll a, genetic diversity, Marine Cyanobacterium Synechococcus, Multiple Evolutionary Origins, North Atlantic, Nucleotide Sequence, rcc, Region, Rna Operon, sargasso sea, Water Column}, doi = {10.1128/AEM.68.3.1180-1191.2002}, author = {Rocap, G and Distel, D L and Waterbury, J B and Chisholm, S W} } @article {Jacquet2001, title = {Cell cycle regulation by light in Prochlorococcus strains}, journal = {Applied and Environmental Microbiology}, volume = {67}, number = {2}, year = {2001}, note = {tex.mendeley-tags: RCC,rcc}, pages = {782{\textendash}790}, abstract = {

The effect of light on the synchronization of cell cycling was investigated in several strains of the oceanic photosynthetic prokaryote Prochlorococcus using flow cytometry. When exposed to a light-dark (L-D) cycle with an irradiance of 25 mu mol of quanta m(-2) s(-1), the low-light-adapted strain SS 120 appeared to be better synchronized than the high-light-adapted strain PCC 9511. Submitting LD-entrained populations to shifts (advances or delays) in the timing of the "light on" signal translated to corresponding shifts in the initiation of the S phase, suggesting that this signal is a key parameter for the synchronization of population cell cycles. Cultures that were shifted from an L-D cycle to continuous irradiance showed persistent diel oscillations of flow-cytometric signals (light scatter and chlorophyll fluorescence) but with significantly reduced amplitudes and a phase shift. Complete darkness arrested most of the cells in the G(1), phase of the cell cycle, indicating that light is required to trigger the initiation of DNA replication and cell division. However, some cells also arrested in the S phase, suggesting that cell cycle controls in Prochlorococcus spp. are not as strict as in marine Synechococcus spp. Shifting Prochlorococcus cells from low to high irradiance translated quasi-instantaneously into an increase of cells in both the S and G(2) phases of the cell cycle and then into faster growth, whereas the inverse shift induced rapid slowing of the population growth rate. These data suggest a close coupling between irradiance levels and cell cycling in Prochloroeoccus spp.

}, keywords = {cyanobacteria, Equatorial Pacific, Gene Expression, Growth, Mediterranean Sea, North Atlantic, Photosynthetic Prokaryote, picoplankton, Populations, rcc, Synechococcus}, doi = {10.1128/AEM.67.2.782-790.2001}, author = {Jacquet, S and Partensky, F and Marie, D and Casotti, R and Vaulot, D} } @article {West2001, title = {Closely related Prochlorococcus genotypes show remarkably different depth distributions in two oceanic regions as revealed by in situ hybridization using 16S rRNA-targeted oligonucleotides}, journal = {Microbiology - UK}, volume = {147}, number = {7}, year = {2001}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1731{\textendash}1744}, abstract = {An in situ hybridization method was applied to the identification of marine cyanobacteria assignable to the genus Procholorococcus using harseradish-peroxidase-labelled 16S rRNA-targeted oligonucleotide probes in combination with tyramide signal amplification (TSA). With this method very bright signals were obtained, in contrast to hybridizations with oligonucleotides monolabelled with fluorochromes, which failed to give positive signals. Genotype-specific oligonucleotides for high light (HL)- and low light (LL)adapted members of this genus were identified by 16S rRNA sequence analyses and their specificities confirmed in whole-cell hybridizations with cultured strains of Prochlorococcus marinus Chisholm et al., 1992, Prochlorococcus sp. and Synechococcus sp. In situ hybridization of these genotype-specific probes to field samples from stratified water bodies collected in the North Atlantic Ocean and the Red Sea allowed a rapid assessment of the abundance and spatial distribution of HL- and LL-adapted Prochlorococcus. In both oceanic regions the LL-adapted Prochlorococcus populations were localized in deeper water whereas the HL-adapted Prochlorococcus populations were not only distinct in each region but also exhibited strikingly different depth distributions, HLI being confined to shallow wafer in the North Atlantic, in contrast to HLII, which was present throughout the water column in the Red Sea.}, keywords = {Escherichia Coli, IDENTIFICATION, Marine Cyanobacterium, Nucleic Acid Probes, Photosynthetic Prokaryote, PICODIV, Populations, rcc, Ribosomal Rna, SEQUENCES, Tyramide Signal Amplification, Whole Cell Hybridization}, doi = {10.1099/00221287-147-7-1731}, author = {West, N J and Schonhuber, W A and Fuller, N J and Amann, R I and Rippka, R and Post, A F and Scanlan, D J} } @article {Jacquet2001a, title = {Diel patterns of growth and division in marine picoplankton in culture}, journal = {Journal of Phycology}, volume = {37}, number = {3}, year = {2001}, note = {tex.mendeley-tags: 2001,rcc,sbr?hyto}, pages = {357{\textendash}369}, abstract = {{The effect of a 12:12-h light:dark (LD) cycle on the phasing of several cell parameters was explored in a variety of marine picophytoplanktonic strains. These included the photosynthetic prokaryotes Pro-chlorococcus (strains MED 4, PCC 9511, and SS 120) and Synechococcus (strains ALMO 03, ROS 04, WH 7803, and WH 8103) and five picoeukaryotes (Bathycoccus prasinos Eikrem et Throndsen, Bolidomonas pacifica Guillou et Chretiennot-Dinet, Micromonas pusilla Manton et Parke, Pelagomonas calceolata Andersen et Saunders, and Pycnococcus provasolii Guillard et al.). Flow cytometric analysis was used to determine the relationship between cell light scatter, pigment fluorescence, DNA (when possible), and the LD cycle in these organisms. Asexpected, growth and division were tightly coupled to the LD cycle for all of these strains. For both Prochlorococcus and picoeukaryotes, chi and intracellular carbon increased throughout the light period as estimated by chi fluorescence and light scatter, respectively. In response to cell division, these parameters decreased regularly during the early part of the dark period, a decrease that either continued throughout the dark period or stopped for the second half of the dark period. For Synechococcus, the decrease of chi and scatter occurred earlier (in the middle of the light period), and for some strains these cellular parameters remained constant throughout the dark period. The timing of division was very similar for all picoeukaryotes and occurred just before the subjective dusk, whereas it was more variable between the different Prochlorococcus and Synechococcus strains. The burst of division for Prochlorococcus SS 120 and PCC 9511 was recorded at the subjective dusk, whereas the MED 4 strain divided later at night. Synechococcus ALMO 03, ROS 04, and WH 7803, which have a low phycourobilin to phycoerythrobilin (PUB:PEB) ratio, divided earlier, and their division was restricted to the light period. In contrast, the high PUB:PEB Synechococcus strain WH 8103 divided preferentially at night. There was a weak linear relationship between the FALS(max):FALS(min) ratio and growth rate calculated from cell counts (r = 0.83}, keywords = {2001, Cell Division, Cyanobacteria Synechococcus, Dividing Cells, Equatorial Pacific, flow cytometry, Mediterranean Sea, Natural Populations, North Pacific Ocean, Photosynthetic Picoplankton, Picophytoplankton Dynamics, rcc, SBR$_\textrmP$hyto, sbr?hyto}, doi = {10.1046/j.1529-8817.2001.037003357.x}, author = {Jacquet, S and Partensky, F and Lennon, J F and Vaulot, D} } @article {Guillou2001, title = {Grazing impact of two small heterotrophic flagellates on Prochlorococcus and Synechococcus}, journal = {Aquatic Microbial Ecology}, volume = {26}, number = {2}, year = {2001}, note = {tex.mendeley-tags: 2001,rcc,sbr?hyto}, pages = {201{\textendash}207}, abstract = {In open oceanic waters, phytoplankton biomass is dominated by organisms below 2 to 3 mum in size (pico- and small nanophytoplankton). The cell concentration of these populations is very stable in time and space as a consequence of nutrient limitation and strong grazing pressure, Although the identity of the organisms that directly graze on picoplankton is largely unknown, they are thought to be very small, i.e. {\textexclamdown}3 to 5 {\textexclamdown}mu{\textquestiondown}m, Here, we analyze the grazing impact of 2 small flagellates, Symbiomonas scintillans and Picophagus flagellatus, upon 2 oceanic cyanobacteria, Prochlorococcus and Synechococcus. S. scintillans does not feed on the 2 cyanobacteria. In contrast, P. flagellatus appears as an active predator capable of drastically reducing prey concentrations. The flagellate displays a substantial division rate of the order of 2 doublings d(-1) when fed on Prochlorococcus cells, but no significant growth is recorded when Synechococcus is used as prey. As the majority ({\textquestiondown} 80\%) of P. flagellatus cells can pass throughout a 2 mum filter, the impact of such tiny predators should be taken into consideration during field experiments that rely on size fractionation to separate grazers from prey.}, keywords = {2001, Algal Class, Equatorial Pacific, Growth Rates, Laboratory Cultures, Marine, Nanoplankton, PICODIV, picoplankton, Prey, rcc, SBR$_\textrmP$hyto, sbr?hyto, Size, Sp Nov}, doi = {10.3354/ame026201}, author = {Guillou, L and Jacquet, S and Chr{\'e}tiennot-Dinet, M.-J. and Vaulot, D} } @article {Dupuy2000, title = {Feeding rate of the oyster Crassostrea gigas in a natural planktonic community of the Mediterranean Thau Lagoon}, journal = {Marine Ecology - Progress Series}, volume = {205}, year = {2000}, note = {ISBN: 0171-8630 Publisher: Inter-Research tex.address: Nordbunte 23, D-21385 Oldendorf Luhe, Germany tex.mendeley-tags: RCC,rcc}, pages = {171{\textendash}184}, abstract = {The Mediterranean Thau Lagoon is an important oyster farming area in Europe. Oyster growth rates are among the highest in France, although chlorophyll a concentration is low. Previous studies have demonstrated that picophytoplankton, nano-microphytoplankton, dinoflagellates and loricate ciliates such as tintinnids are abundant. However, heterotrophic flagellates and aloricate ciliates have not been investigated. The aim of this study was to assess picophytoplankton, protist and zooplankton abundances in the Lagoon and to investigate the particular structure of the microbial food web, which may explain such paradoxical oyster growth. In oligotrophic waters in the Thau Lagoon, the picoeukaryote Ostreococcus tauri is the dominant autotrophic picoplankter, with an abundance maximum in summer. On 17 August 1998, following a rainfall event, pico- and nanophytoplankton abundances were not as high as expected and we observed a high abundance of large diatoms. At this time, the available carbon resources were produced by microphytoplankton (84.5\%), and picoplank-tonic cells represented only 1.27 \% in terms of carbon. Heterotrophic cells were low in abundance and constituted {\textexclamdown}14\% of carbon resources. In order to evaluate the importance of the {\textquoteright}protozoan trophic link{\textquoteright} for energy transfer from the microbial food web to large benthic suspension feeders, the oyster Crassostrea gigas was offered a planktonic community as potential prey. In the grazing experiment, all {\textquestiondown}5 mum flagellates, microphytoplankton, dinoflagellates, ciliates and large zooplankton were retained by the oyster gills. Only flagellates {\textexclamdown}5 pm and O. Tauri were not very well retained (45 and 2\% respectively). The high clearance rates of C. Gigas found in this experiment can be explained by a low concentration of suspended particulate matter (0.65 mg l(-1)). The oysters adapted their retention mechanism when they Lived in oligotrophic waters. These results indicate that, under the given experimental conditions, picophytoplankton did not represent a valuable trophic resource for farmed oysters because (1) C. Gigas cannot retain picoparticles and (2) the picoplankton represented a poor carbon resource capable of being transferred via a weak heterotrophic protist community. In the oyster pens of the Thau Lagoon during this study, microphytoplanktonic primary producers, in particular diatoms, were the main food sources for bivalve suspension feeders.}, keywords = {ABUNDANCE, bivalve, carbon, COASTAL WATERS, EPIFLUORESCENCE MICROSCOPY, FILTRATION-RATE, food source, FOOD-CHAINS, GEUKENSIA-DEMISSA, heterotrophic protist, microbial food web, MYTILUS-EDULIS, oyster, PARTICLE SELECTION, picophytoplankton, rcc, RETENTION, Thau Lagoon, trophic link}, doi = {10.3354/meps205171}, author = {Dupuy, C and Vaquer, A and LamHoai, T and Rougier, C and Mazouni, N and Lautier, J and Collos, Y and LeGall, S} } @article {Fawley2000, title = {Phylogenetic analyses of 18S rDNA sequences reveal a new coccoid lineage of the Prasinophyceae (Chlorophyta)}, journal = {Journal of Phycology}, volume = {36}, number = {2}, year = {2000}, note = {ISBN: 0022-3646 Publisher: Phycological Soc Amer Inc tex.address: 810 East 10Th St, Lawrence, KS 66044, USA tex.mendeley-tags: RCC,rcc}, pages = {387{\textendash}393}, abstract = {Phylogenetic analyses of 18S rDNA sequences from 25 prasinophytes, including 10 coccoid isolates, reveals that coccoid organisms are-found in at least three prasinophyte lineages, The coccoid Ostreococcus tauri is included in the Mamiellales lineage and Pycnococcus provasolii is allied with the f dfellate Pseudoscourfieldia marina. A previously undescribed prasinophyte lineage is comprised of the coccoid Prasinococcus cf. Capsulatus (CCMP 1407) and other isolates tentatively identified as Prasinococcussp. (CCMP 1202, CCMP 1614, and CCMP 1194), as well as three unnamed coccoids (CCMP 1193, CCMP 1413, and CCMP 1220). No flagellate organisms are known from this lineage. Organisms of this new lineage share some characteristics of both the Pycnococcaceae and the Mamiellales, although relationships among these separate lineages were not supported by bootstrap analyses. An additional unnamed coccoid isolate (CCMP 1205) is separate from all major prasinophyte lineages. The analyses did not resolve the relationships among the major prasinophyte lineages, although they support previous conclusions that the Prasinophyceae are not monophyletic.}, keywords = {ALGAL CAROTENOIDS, coccoid algae, EVOLUTIONARY TREES, Gen, GREEN-ALGAE, LIGHT-HARVESTING COMPLEX, MICROMONADOPHYCEAE CHLOROPHYTA, Prasinophyceae, PRASINOXANTHIN, PSEUDOSCOURFIELDIA-MARINA, rcc, RDNA, RIBOSOMAL-RNA SEQUENCES, Sequence Analysis, sp-nov}, doi = {10.1046/j.1529-8817.2000.99105.x}, author = {Fawley, M W and Yun, Y and Qin, M} } @article {Guillou1999, title = {Bolidomonas: a new genus with two species belonging to a new algal class, the Bolidophyceae (Heterokonta)}, journal = {Journal of Phycology}, volume = {35}, year = {1999}, note = {tex.mendeley-tags: 1999,rcc,sbr?hyto}, pages = {368{\textendash}381}, abstract = {A new algal class, the Bolidophyceae (Heterokonta), is described from one genus, Bolidomonas, gen, nov., and two species, Bolidomonas pacifica, sp, nov and Bolidomonas mediterranea, sp, nov., isolated from the equatorial Pacific Ocean and the Mediterranean Sea, respectively. Both species are approximately 1.2 mu m in diameter and have two unequal flagella; the longer flagellum bears tubular hairs, whereas the shorter is smooth. The flagellar basal apparatus is restricted to two basal bodies, and there is no transitional helix. Cells are naked, devoid of walls or siliceous structures. The internal cellular organization is simple with a single plastid containing a ring genophore and a girdle lamella, one mitochondrion with tubular cristae, and one Golgi apparatus close to the basal bodies. The Mediterranean and the Pacific species differ in the insertion angle between their flagella and their pattern of swimming, these differences possibly being linked to each other. Analyses of the SSU rDNA gene place the two strains as a sister group to the diatoms, Moreover, pigment analyses confirm this position, as fucoxanthin is found as the major carotenoid in both lineages. These data strongly suggest that the ancestral heterokont that gave rise to the diatom lineage was probably a biflagellated unicell.}, keywords = {10$_\textrmb$est, 1999, Bolidophyceae, CELL-CYCLE, CHRYSOPHYCEAE, diatoms, DIVINYL-CHLOROPHYLL, FINE-STRUCTURE, FLAGELLAR APPARATUS, Heterokonta, Marine, marine picoeukaryotes, oligotrophic ocean, rcc, RNA, SBR$_\textrmP$hyto, sbr?hyto, SEQUENCE, sp-nov, stramenopiles, ultrastructure}, doi = {10.1046/j.1529-8817.1999.3520368.x}, author = {Guillou, L and Chr{\'e}tiennot-Dinet, M.-J. and Medlin, L K and Claustre, H and Loiseaux-de Go{\"e}r, S and Vaulot, D} } @article {Guillou1999a, title = {Diversity and abundance of Bolidophyceae (Heterokonta) in two oceanic regions}, journal = {Applied and Environmental Microbiology}, volume = {65}, number = {10}, year = {1999}, note = {ISBN: 0099-2240 Publisher: Amer Soc Microbiology tex.address: 1325 Massachusetts Avenue, NW, Washington, DC 20005-4171, USA tex.mendeley-tags: 1999,rcc,sbr?hyto}, pages = {4528{\textendash}4536}, abstract = {The diversity and abundance of the Bolidophyceae (Heterokonta), a newly described picoplanktonic algal class which is a sister group to the diatoms, was assessed in the equatorial Pacific Ocean and in the Mediterranean Sea by culture isolation, molecular biology techniques, and pigment analyses. Eight strains of Bolidophyceae were isolated in culture from different mesotrophic and oligotrophic areas. The corresponding small subunit (SSU) rRNA gene sequences allowed us to design two probes specific for the Bolidophyceae. These probes have been used in natural samples (i) to selectively amplify and detect Bolidophyceae sequences and (ii) to quantify the relative abundance of Bolidophyceae within the picoeukaryote community. Sequences available to date indicate that the class Bolidophyceae comprises at least three different clades, two corresponding to the previously described species Bolidomonas pacifica and Bolidomonas mediterranea and the third one corresponding to a subspecies of B. Pacifica. Amplification of the SSU rRNA gene from natural samples with universal primers and hybridization using a Bolidomonas-specific probe followed by a eukaryote-specific probe allowed us to estimate the contribution of the Bolidophyceae to the eukaryotic DNA in both Pacific and Mediterranean waters to be lower than 1\%. Similarly, high-performance liquid chromatography analyses of fucoxanthin, the major carotenoid present in Bolidophyceae, indicated that less than 4\% of the total chlorophyll a in the picoplanktonic fraction in the equatorial Pacific was due to Bolidophyceae. Consequently, although strains of Bolidophyceae have been isolated from samples collected at several stations, this new class seems to have been a minor component of the natural picoeukaryotic populations in the ecosystems investigated, at least during the periods sampled.}, keywords = {1999, ATLANTIC, BACTERIOPLANKTON, community structure, flow-cytometry, MOLECULAR PHYLOGENY, PACIFIC, phytoplankton, PIGMENT SIGNATURES, rcc, RNA GENE SEQUENCE, SBR$_\textrmP$hyto, sbr?hyto, ULTRAPHYTOPLANKTON}, doi = {10.1128/AEM.65.10.4528-4536.1999}, author = {Guillou, L and Moon-van der Staay, S Y and Claustre, H and Partensky, F and Vaulot, D} } @article {Guillou1999b, title = {Symbiomonas scintillans gen. et sp nov and Picophagus flagellatus gen. et sp nov (Heterokonta): Two new heterotrophic flagellates of picoplanktonic size}, journal = {Protist}, volume = {150}, number = {4}, year = {1999}, note = {ISBN: 1434-4610 Publisher: Urban \& Fischer Verlag tex.address: Branch Office Jena, P O Box No.100 537, D-07705 Jena, Germany tex.mendeley-tags: 1999,rcc,sbr?hyto}, pages = {383{\textendash}398}, abstract = {Two new oceanic free-living heterotrophic Heterokonta species with picoplanktonic size ({\textexclamdown} 2 mu m) are described, Symbiomonas scintillans Guillou et Chretiennot-Dinet gen. Ef sp. Nov, was isolated from samples collected both in the equatorial Pacific Ocean and the Mediterranean Sea. This new species possesses ultrastructural features of the bicosoecids, such as the absence of a helix in the flagellar transitional region (found in Cafeteria roenbergensis and in a few bicosoecids), and a flagellar root system very similar to that of C. Roenbergensis, Acronema sippewissettensis, and Bicosoeca maris. This new species is characterized by a single flagellum with mastigonemes, the presence of endosymbiotic bacteria located close to the nucleus, the absence of a lorica and a R3 root composed of a 6+3+x microtubular structure. Phylogenetical analyses of nuclear-encoded SSU rDNA gene sequences indicate that this species is close to the bicosoecids C. Roenbergensis and Siluania monomastiga. Picophagus flagellatus Guillou et Chretiennot-Dinet gen. Et sp. Nov. Was collected in the equatorial Pacific Ocean, Cells are naked and possess two flagella, This species is characterized by the lack of a transitional helix and lateral filaments on the flagellar tubular hairs, the absence of siliceous scales, two unequal flagella, R1 + R3 roots, and the absence of a rhizoplast. SSU rDNA analyses place this strain at the base of the Chrysophyceae/Synurophyceae lineages.}, keywords = {1999, APPARATUS, DEVELOPAYELLA-ELEGANS, EMPHASIS, MOLECULAR PHYLOGENY, picophytoplankton, PLASTIDS, rcc, RDNA, SBR$_\textrmP$hyto, sbr?hyto, SEQUENCES}, doi = {10.1016/S1434-4610(99)70040-4}, author = {Guillou, L and Chr{\'e}tiennot-Dinet, M.-J. and Boulben, S and Moon-van der Staay, S Y and Vaulot, D} } @article {Courties1998, title = {Phylogenetic analysis and genome size of Ostreococcus tauri (Chlorophyta, Prasinophyceae)}, journal = {Journal of Phycology}, volume = {34}, number = {5}, year = {1998}, note = {tex.mendeley-tags: RCC745}, pages = {844{\textendash}849}, abstract = {Ostreococcus tauri Courties et Chretiennot-Dinet is the smallest described autotrophic eukaryote dominating the phytoplanktonic assemblage of the marine Mediterranean Thau lagoon (France). Its taxonomic position was partly elucidated from ultrastructure and high-pressure liquid chromatography (HLPC) pigment analysis. The sequence analysis of the 18S rDNA gene of O. Tauri measured here is available in EMBL Nucleotide Sequence Database (accession number: Y15814) and allowed to clarify its phylogenetic position. O. Tauri belongs to the Prasinophyceae and appears very close to Mantoniella, a typical scaly Prasinophyceae, morphologically very different from the naked and coccoid Ostreococcus. An electrophoretic analysis of O. Tauri shows that the nucleus contains 10.20 mbp. This small genome fragmented into 14 chromosomes ranging in size from 300 to 1500 kbp, confirms the minimalist characteristics of Ostreococcus tauri.}, keywords = {rcc, RCC745, SBR$_\textrmP$hyto}, doi = {10.1046/j.1529-8817.1998.340844.x}, author = {Courties, C and Perasso, R and Chr{\'e}tiennot-Dinet, M.-J. and Gouy, M and Guillou, L and Troussellier, M} } @article {toledo_synechococcus_1997, title = {Synechococcus diversity in the California current as seen by RNA polymerase (rpoC1) gene sequences of isolated strains.}, journal = {Applied and environmental microbiology}, volume = {63}, number = {11}, year = {1997}, pages = {4298{\textendash}4303}, keywords = {RCC1086}, issn = {0099-2240}, doi = {10.1128/AEM.63.11.4298-4303.1997}, url = {https://AEM.asm.org/content/63/11/4298}, author = {Toledo, G and Palenik, B} } @article {Scanlan1996, title = {High degree of genetic variation in Prochlorococcus (Prochlorophyta) revealed by RFLP analysis}, journal = {European Journal of Phycology}, volume = {31}, number = {1}, year = {1996}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1{\textendash}9}, keywords = {DIVINYL CHLOROPHYLL-A, FAMILY, Marine Synechococcus, Mediterranean Sea, Multiple Evolutionary Origins, north-atlantic, NUCLEOTIDE-SEQUENCE, picoplankton, Prokaryote, rcc, RCC SBR$_\textrmP$hyto, UNICELLULAR CYANOBACTERIUM}, doi = {10.1080/09670269600651131}, author = {Scanlan, D J and Hess, W R and Partensky, F and Newman, J and Vaulot, D} } @article {Shimada1996, title = {Vertical distributions and photosynthetic action spectra of two oceanic picophytoplankers, Prochlorococcus marinus and Synechococcus sp}, journal = {Marine Biology}, volume = {127}, year = {1996}, note = {tex.mendeley-tags: RCC,rcc}, pages = {15{\textendash}23}, keywords = {OPTICAL-PROPERTIES, Photosynthesis, rcc, \#PROCHLOROCOCCUS}, doi = {10.1007/BF00993639}, author = {Shimada, A and Maruyama, T and Miyachi, S} } @article {Moore1995, title = {Comparative physiology of Synechococcus and Prochlorococcus: influence of light and temperature on growth, pigments, fluorescence and absorptive properties}, journal = {Marine Ecology - Progress Series}, volume = {116}, year = {1995}, note = {tex.mendeley-tags: RCC,rcc}, pages = {259{\textendash}275}, keywords = {GROWTH RATE, Light, MARINE OPTICS, rcc, Synechococcus, temperature, \#PROCHLOROPHYTE}, doi = {10.3354/meps116259}, author = {Moore, L R and Goericke, R and Chisholm, S W} } @article {Chretiennot-Dinet1995, title = {A new marine picoeucaryote: Ostreococcus tauri gen. et sp. nov. (Chlorophyta, Prasinophyceae)}, journal = {Phycologia}, volume = {34}, number = {4}, year = {1995}, note = {tex.mendeley-tags: RCC745}, pages = {285{\textendash}292}, keywords = {FRESH-WATER ECOSYSTEMS, morphology, picoplankton, pigments, PROCHLOROCOCCUS-MARINUS, Prokaryote, rcc, RCC745, Size}, doi = {10.2216/i0031-8884-34-4-285.1}, author = {Chr{\'e}tiennot-Dinet, M.-J. and Courties, C and Vaquer, A and Neveux, J and Claustre, H and Lautier, J and Machado, M C} } @article {Simon1994, title = {Characterization of oceanic photosynthetic picoeukaryotes by flow cytometry analysis}, journal = {Journal of Phycology}, volume = {30}, year = {1994}, note = {tex.mendeley-tags: RCC,rcc}, pages = {922{\textendash}935}, keywords = {flow cytometry, hplc, pigments, rcc, RCC SBR$_\textrmP$hyto, \#PICOPLANKTON}, doi = {10.1111/j.0022-3646.1994.00922.x}, author = {Simon, N and Barlow, R G and Marie, D and Partensky, F and Vaulot, D} } @article {Vaulot1994, title = {Phaeocystis spp.: morphology, ploidy, pigment composition and genome size of cultured strains}, journal = {Journal of Phycology}, volume = {30}, year = {1994}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1022{\textendash}1035}, keywords = {rcc, RCC SBR$_\textrmP$hyto}, doi = {10.1111/j.0022-3646.1994.01022.x}, author = {Vaulot, D and Birrien, J.-L. and Marie, D and Casotti, R and Veldhuis, M J W and Kraay, G W and Chr{\'e}tiennot-Dinet, M.-J.} } @article {Partensky1993, title = {Photoacclimation of Prochlorococcus sp. (Prochlorophyta) strains isolated from the North Atlantic and the Mediterranean Sea}, journal = {Plant Physiology}, volume = {101}, year = {1993}, note = {tex.mendeley-tags: RCC,rcc,sbr?hyto}, pages = {295{\textendash}296}, keywords = {hplc, Photosynthesis, Pigment, rcc, RCC SBR$_\textrmP$hyto, sbr?hyto, \#PROCHLOROPHYTE}, doi = {10.1104/pp.101.1.285}, author = {Partensky, F and Hoepffner, N and Li, W K W and Ulloa, O and Vaulot, D} } @article {Morel1993, title = {Prochlorococcus and Synechococcus: a comparative study of their size, pigmentation and related optical properties}, journal = {Journal of Marine Research}, volume = {51}, year = {1993}, note = {tex.mendeley-tags: 1993,rcc,sbr?hyto}, pages = {617{\textendash}649}, keywords = {1993, hplc, OPTICS, Pigment, rcc, SBR$_\textrmP$hyto, sbr?hyto, Synechococcus, \#PROCHLOROPHYTE}, doi = {10.1357/0022240933223963}, author = {Morel, A and Ahn, Y.-W. and Partensky, F and Vaulot, Daniel and Claustre, H} } @article {Chisholm1992, title = {\textit{Prochlorococcus marinus nov. gen. nov. sp.: an oxyphototrophic marine prokaryote containing divinyl chlorophyll a and b}, journal = {Archives of Microbiology}, volume = {157}, year = {1992}, note = {tex.mendeley-tags: RCC,rcc}, pages = {297{\textendash}300}, keywords = {rcc, systematics, \#PROCHLOROPHYTE}, doi = {10.1007/BF00245165}, author = {Chisholm, S W and Frankel, S L and Goericke, R and Olson, R J and Palenik, B and Waterbury, J B and West-Johnsrud, L and Zettler, E R} } @article {Raghu-Kumar1988, title = {Schizochytrium mangrovei sp. nov., a thraustochytrid from mangroves in India}, journal = {Transactions of the British Mycological Society}, volume = {90}, number = {4}, year = {1988}, note = {ISBN: 0007-1536 Publisher: British Mycological Society tex.mendeley-tags: RCC893}, month = {jun}, pages = {627{\textendash}631}, abstract = {Schizochytrium mangrovei sp. nov. on decaying mangrove leaves is described from Goa, India. In sea water/pine pollen cultures, the encysted zoospore divides by repeated binary divisions to form 4, 6, 8 or 12 cells. Instead of forming sporangia as in the other species of Schizochytrium, these cells directly become zoospores. In nutrient liquid media, the developmental stages resemble those of Ulkenia. A key to the species of Schizochytrium is given.}, keywords = {RCC893}, issn = {00071536}, doi = {10.1016/S0007-1536(88)80068-8}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0007153688800688}, author = {Raghu-Kumar, S.} } @inbook {Waterbury1986, title = {Biological and ecological characterization of the marine unicellular cyanobacterium Synechococcus}, booktitle = {Photosynthetic picoplankton}, volume = {214}, year = {1986}, note = {tex.mendeley-tags: Canad. Bull. Fish. Aquatic Sci.,RCC,rcc}, pages = {71{\textendash}120}, keywords = {Canad. Bull. Fish. Aquatic Sci., phytoplankton, rcc, Synechococcus}, author = {Waterbury, J B and Watson, S W and Valois, F W and Franks, D G}, editor = {Platt, T and Li, W K W} } @article {ISI:A1984AAU2400012, title = {Purification and properties of ι-carrageenase from a marine bacterium}, journal = {Canadian Journal of Microbiology}, volume = {30}, number = {12}, year = {1984}, note = {tex.mendeley-tags: RCC5933}, month = {dec}, pages = {1500{\textendash}1506}, keywords = {RCC5933}, issn = {0008-4166}, doi = {10.1139/m84-239}, url = {http://www.nrcresearchpress.com/doi/10.1139/m84-239}, author = {Greer, C. W. and Yaphe, W.} }