Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Marine Ecology Progress Series 243-261 Microsatellites Mitochondrial DNA Gene flow Demography Mediterranean Sea Mugilidae Bayesian clustering Bayesian skyline plot MEDITERRANNEE MER NOIRE 2013 fdi:010058975 ENG Marine Ecology Progress Series 0171-8630 ISI:000314368600019 10.3354/meps10080 https://www.documentation.ird.fr/hor/fdi:010058975 https://www.documentation.ird.fr/intranet/publi/2013/03/010058975.pdf 474 Horizon (IRD) The population structure and evolutionary history of Mugil cephalus were investigated across 18 sampling sites in the NE Atlantic Ocean, Mediterranean and Black Seas, using 2 classes of genetic markers: sequence polymorphism of an 857 bp fragment of mitochondrial (mtDNA) cytochrome b, and allele size variation at 7 nuclear loci. The level of nucleotide diversity recovered with the mtDNA marker was very low (similar to 0.6% divergence), indicating the presence of a single clade over the entire area. Mismatch distribution, Bayesian skyline plots and associated statistics revealed a recent demographic crash followed by population expansion, but nuclear data indicated population constancy in the area covered in this study. While a single clade was detected, significant mtDNA genetic differentiation was, however, observed between the samples from the Black Sea and the samples from other (sub-) basins (Phi(ST) = 0.17; p = 0.029). The nuclear loci also revealed significant genetic differentiation and isolation-by-distance in M. cephalus. Patterns of genetic structure were, however, significantly more pronounced with nuclear than with mtDNA markers; the former indicated the presence of 3 (Bayesian clustering) to 6 (Monmonnier's method) populations. The highest levels of genetic heterogeneity at nuclear markers occurred at the well-known Almeria-Oran Front, but also in the Bosporus Strait. Thus, both sets of markers revealed the importance of this strait as a barrier to gene flow, probably during the Pleistocene. The results also revealed genetic heterogeneity in the eastern Mediterranean basin, and suggested that the population expanded from this sub-basin towards the Atlantic Ocean and Black Sea. 036 ; 020 UR238 / UR226 Tunisie