@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 {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 {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 {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 {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.} } @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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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 {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} }