Author:

Keywords:

population size, genetic distance, gobiidae, marine fish, northeastern atlantic, microsatellites, sex-biased dispersal, cod gadus-morhua, pomatoschistus-minutus, sand goby, microsatellite loci, genetic-structure, linkage disequilibrium, mitochondrial-dna, mediterranean sea, baltic sea, Science & Technology, Life Sciences & Biomedicine, Ecology, Evolutionary Biology, Genetics & Heredity, Environmental Sciences & Ecology, Northeastern Atlantic, SEX-BIASED DISPERSAL, POMATOSCHISTUS-MINUTUS, SAND GOBY, GENETIC-STRUCTURE, MITOCHONDRIAL-DNA, LINKAGE DISEQUILIBRIUM, MICROSATELLITE MARKERS, PATAGONIAN TOOTHFISH, COMPUTER-PROGRAM, ATLANTIC-OCEAN, Animals, Cell Nucleus, DNA, Mitochondrial, Europe, Evolution, Molecular, Female, Genetic Variation, Genotype, Male, Microsatellite Repeats, Molecular Sequence Data, Oceans and Seas, Perciformes, Phylogeny, 0603 Evolutionary Biology, 0604 Genetics, 3104 Evolutionary biology, 3105 Genetics

Abstract:

An increasing number of phylogeographic studies on marine species shows discordant patterns in the degree of population differentiation between nuclear and mitochondrial markers. To understand better which factors have the potential to cause these patterns of discordance in marine organisms, a population genetic study was realized on the sand goby Pomatoschistus minutus (Pallas 1770; Gobiidae, Teleostei). Sand gobies from eight European locations were genotyped at eight microsatellite markers. Microsatellites confirmed the global phylogeographical pattern of P. minutus observed with mitochondrial DNA (mtDNA) markers and nuclear allozyme markers. Three groups consistent with the mitochondrial lineages were defined (the Mediterranean, Iberian and North Atlantic groups) and indications of a recent founder event in the northern Baltic Sea were found. Nevertheless, differences in the degree of population differentiation between the nuclear and mitochondrial markers were large (global F-ST-values for microsatellites = 0.0121; for allozymes = 0.00831; for mtDNA = 0.4293). Selection, sex-biased dispersal, homoplasy and a high effective population size are generally accepted as explanations for this mitonuclear discrepancy in the degree of population differentiation. In this study, selection on mtDNA and microsatellites, male-biased dispersal and homoplasy on microsatellite markers are unlikely to be a main cause for this discrepancy. The most likely reason for the discordant pattern is a recent demographical expansion of the sand goby, resulting in high effective population sizes slowing down the differentiation of nuclear DNA. Heredity (2010) 105, 532-542; doi:10.1038/hdy.2010.9; published online 10 February 2010