title: Divergence with gene flow between Ponto-Caspian refugia in an anadromous cyprinid Rutilus frisii revealed by multiple gene phylogeography.
abstract: The Black and Caspian Seas have experienced alternating periods of isolation and interconnection over many Milankovitch climate oscillations and most recently became separated when the meltwater overflow from the Caspian Sea ceased at the end of the last glaciation. Climate-induced habitat changes have indisputably had profound impacts on distribution and demography of aquatic species, yet uncertainties remain about the relative roles of isolation and dispersal in the response of species shared between the Black and Caspian Sea basins. We examined these issues using phylogeographical analysis of an anadromous cyprinid fish Rutilus frisii. Bayesian coalescence analyses of sequence variation at two nuclear and one mitochondrial genes suggest that the Black and Caspian Seas supported separate populations of R. frisii during the last glaciation. Parameter estimates from the fitted isolation-with-migration model showed that their separation was not complete, however, and that the two populations continued to exchange genes in both directions. These analyses also suggested that majority of migrations occurred during the Pleistocene, showing that the variation shared between the Black and Caspian Seas is the result of ancient dispersal along the temporary natural connections between the basins, rather than of incomplete lineage sorting or recent human-mediated dispersal. Gene flow between the refugial populations was therefore an important source of genetic variation, and we suggest that it facilitated the evolutionary response of the populations to changing climate.
authors.affiliation: Department of Vertebrate Evolutionary Biology and Genetics, Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, CZ-27721 Libéchov, Czech Republic. kotlik@iapg.cas.cz
authors.forename: Petr
authors.initials: P
authors.lastname: Kotlík
authors.forename: Silvia
authors.initials: S
authors.lastname: Marková
authors.forename: Lukás
authors.initials: L
authors.lastname: Choleva
authors.forename: Nina G
authors.initials: NG
authors.lastname: Bogutskaya
authors.forename: F Guler
authors.initials: FG
authors.lastname: Ekmekçi
authors.forename: Petya P
authors.initials: PP
authors.lastname: Ivanova
mesh_terms: D000818:Animals; D001483:Base Sequence; D003530:Cyprinidae / Q000235:genetics*; D045303:Cytochromes b / Q000235:genetics; D005618:Fresh Water; D051456:Gene Flow; D014644:Genetic Variation; D005843:Geography; D007438:Introns; D025261:Mitochondrial Proton-Translocating ATPases / Q000235:genetics; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D010802:Phylogeny; D021122:Protein Subunits / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D021122:Protein Subunits; D012269:Ribosomal Proteins; C037442:ribosomal protein S7; D045303:Cytochromes b; D025261:Mitochondrial Proton-Translocating ATPases