FN Archimer Export Format PT J TI Evolutionary processes and cellular functions underlying divergence in Alexandrium minutum BT AF LE GAC, Mickael METEGNIER, Gabriel CHOMERAT, Nicolas MALESTROIT, Pascale QUERE, Julien BOUCHEZ, Olivier SIANO, Raffaele DESTOMBE, Christophe GUILLOU, Laure CHAPELLE, Annie AS 1:1;2:1,2;3:3;4:1;5:1;6:4;7:1;8:2;9:5;10:1; FF 1:PDG-ODE-DYNECO-PELAGOS;2:PDG-ODE-DYNECO-PELAGOS;3:PDG-ODE-LITTORAL-LERBO;4:PDG-ODE-DYNECO-PELAGOS;5:PDG-ODE-DYNECO-PELAGOS;6:;7:PDG-ODE-DYNECO-PELAGOS;8:;9:;10:PDG-ODE-DYNECO-PELAGOS; C1 IFREMER, DYNECO PELAGOS, F-29280 Plouzane, France. Sorbonne Univ, Univ Paris 06, Stn Biol Roscoff, CNRS,PUCCh,UACH,UMI 3614,Evolutionary Biol & Ecol, Pl Georges Teissier,CS90074, F-29688 Roscoff, France. IFREMER, Stn Biol Marine, F-29900 Concarneau, France. INRA Auzeville, GeT PlaGe, Genotoul, Castanet Tolosan, France. Sorbonne Univ, Univ Paris 06, Stn Biol Roscoff, CNRS,UMR 7144, Pl Georges Teissier CS90074, F-29688 Roscoff, France. C2 IFREMER, FRANCE UNIV PARIS 06, FRANCE IFREMER, FRANCE INRA, FRANCE UNIV PARIS 06, FRANCE SI BREST CONCARNEAU SE PDG-ODE-DYNECO-PELAGOS PDG-ODE-LITTORAL-LERBO IN WOS Ifremer jusqu'en 2018 copubli-france copubli-p187 copubli-univ-france IF 6.086 TC 23 UR https://archimer.ifremer.fr/doc/00347/45857/45529.pdf LA English DT Article DE ;Dinoflagellates;harmful algal blooms;Populations Genomics;Pseudocryptic species;speciation AB Understanding divergence in the highly dispersive and seemingly homogeneous pelagic environment for organisms living as free drifters in the water column remains a challenge. Here, we analyzed the transcriptome wide mRNA sequences, as well as the morphology of 18 strains of Alexandrium minutum, a dinoflagellate responsible for Harmful Algal Blooms worldwide, to investigate the functional bases of a divergence event. Analysis of the joint site frequency spectrum (JSFS) pointed toward an ancestral divergence in complete isolations followed by a secondary contact resulting in gene flow between the two diverging groups, but heterogeneous across sites. The sites displaying fixed SNPs were associated with a highly restricted gene flow and a strong over-representation of non-synonymous polymorphism, suggesting the importance of selective pressures as drivers of the divergence. The most divergent transcripts were homologs to genes involved in calcium/potassium fluxes across the membrane, calcium transduction signal and saxitoxin production. The implication of these results in terms of ecological divergence and build-up of reproductive isolation are discussed. Dinoflagellates are especially difficult to study in the field at the ecological level due to their small size and the dynamic nature of their natural environment, but also at the genomic level due to their huge and complex genome and the absence of closely related model organism. This study illustrates the possibility to identify traits of primary importance in ecology and evolution starting from high throughput sequencing data, even for such organisms. PY 2016 PD OCT SO Molecular Ecology SN 0962-1083 PU Wiley-blackwell VL 25 IS 20 UT 000385611300010 BP 5129 EP 5143 DI 10.1111/mec.13815 ID 45857 ER EF