Genetic delineation between and within the widespread coccolithophore morpho-species Emiliania huxleyi and Gephyrocapsa oceanica (Haptophyta)

• Published in: Journal of Phycology
• Main Authors: Bendif, El Mahdi, Probert, Ian, Carmichael, Margaux, Romac, Sarah, Hagino, Kyoko, de Vargas, Colomban
• Other Authors: Evolution des Protistes et Ecosystèmes Pélagiques (EPEP), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff Roscoff (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff Roscoff (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Okayama University, European Research Council under the European Community's Seventh Framework Programme (EC-FP7) through the European Project on Ocean Acidification (EPOCA) 211384, Marie Curie Intra-European Fellowship FP7-PEOPLE-2012-IEF, ASSEMBLE 227 799, Interreg IV program MARINEXUS the EU Era-Net BiodivERsA program, ``Investissements d'Avenir'' project wOrld oCEAN biOressources, biotechnologies, and Earth-systeM servICeS (OCEANOMICS, CdV), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2014
• Subjects: coccolithophore; DNA barcoding; Emiliania huxleyi; Gephyrocapsa oceanica; phylogeny; species complex; [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology; [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics; Phylogenetics and taxonomy; Ocean acidification
• Online Access: https://hal.science/hal-01258218; https://hal.science/hal-01258218/document; https://hal.science/hal-01258218/file/bendif2014.pdf; https://doi.org/10.1111/jpy.12147

International audience Emiliania huxleyi and Gephyrocapsa oceanica are abundant coccolithophore morpho-species that play key roles in ocean carbon cycling due to their importance as both primary producers and cal-cifiers. Global change processes such as ocean acidification impact these key calcifying species. The physiology of E.huxleyi, a developing model species, has been widely studied, but its genetic delineation from G.oceanica remains unclear due to a lack of resolution in classical genetic markers. Using nuclear (18S rDNA and 28S rDNA), mitochondrial (cox1, cox2, cox3, rpl16, and dam), and plastidial (16S rDNA, rbcL, tufA, and petA) DNA markers from 99 E.huxleyi and 44 G.oceanica strains, we conducted a multigene/multistrain survey to compare the suitability of different markers for resolving phylogenetic patterns within and between these two morpho-species. The nuclear genes tested did not provide sufficient resolution to discriminate between the two morpho-species that diverged only 291Kya. Typical patterns of incomplete lineage sorting were generated in phylogenetic analyses using plastidial genes. In contrast, full morpho-species delineation was achieved with mitochondrial markers and common intra-morpho-species phylogenetic patterns were observed despite differing rates of DNA substitution. Mitochondrial genes are thus promising barcodes for distinguishing these coccolithophore morpho-species, in particular in the context of environmental monitoring.