Analysis of microsatellite DNA polymorphisms in rockfish Sebastes thompsoni and application to population genetics studies.

Population differentiation and relationships among 6 natural rockfish populations collected from northern coastal seas around Japan were assayed using microsatellite DNA loci. Seven loci examined were polymorphic in all populations. The number of alleles per locus ranged from 6.7 to 9.3, and the average of observed and expected heterozygosity ranged from 0.63 to 0.68, and from 0.66 to 0.69, respectively. The observed genotype frequencies at each locus were almost in agreement with Hardy-Weinberg expectations with two exceptions (P <.05). The allele frequencies of 16 population pairs were significantly different (P <.05). Genetic distance (D(A)) between 6 populations ranged from 0.03 to 0.08. According to a neighbor-joining tree generated from the D(A) values, the 6 populations fell into 3 clusters. These clusters were correlated with the geographical positions of each population; larval dispersions due to water current were also found to have an effect on these results.