@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 {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 {bendif_repeated_2019,
	title = {Repeated species radiations in the recent evolution of the key marine phytoplankton lineage Gephyrocapsa},
	journal = {Nature Communications},
	volume = {10},
	number = {1},
	year = {2019},
	pages = {4234},
	abstract = {Abstract Phytoplankton account for nearly half of global primary productivity and strongly affect the global carbon cycle, yet little is known about the forces that drive the evolution of these keystone microscopic organisms. Here we combine morphometric data from the fossil record of the ubiquitous coccolithophore genus Gephyrocapsa with genomic analyses of extant species to assess the genetic processes underlying Pleistocene palaeontological patterns. We demonstrate that all modern diversity in Gephyrocapsa (including Emiliania huxleyi ) originated in a rapid species radiation during the last 0.6 Ma, coincident with the latest of the three pulses of Gephyrocapsa diversification and extinction documented in the fossil record. Our evolutionary genetic analyses indicate that new species in this genus have formed in sympatry or parapatry, with occasional hybridisation between species. This sheds light on the mode of speciation during evolutionary radiation of marine phytoplankton and provides a model of how new plankton species form.},
	keywords = {RCC1253, RCC1296, RCC3370, RCC3711, RCC4028, RCC4030, RCC4032, RCC4033, RCC4034},
	issn = {2041-1723},
	doi = {10.1038/s41467-019-12169-7},
	url = {https://www.nature.com/articles/s41467-019-12169-7},
	author = {Bendif, El Mahdi and Nevado, Bruno and Wong, Edgar L. Y. and Hagino, Kyoko and Probert, Ian and Young, Jeremy R. and Rickaby, Rosalind E. M. and Filatov, Dmitry A.}
}
@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 {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}
}
