@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 {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 {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 {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 {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 {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 {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 {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}
}
