Population genetic differentiation of white-spotted char Salvelinus leucomaenis (Pallas) in Russian Far East

Abstract

The genetic structure of the populations in white-spotted char Salvelinus leucomaenis (family Salmonidae) was determined based on variations in ten microsatellite DNA loci in samples from different parts of the species range in the Russian Far East. In a number of samples, variations in 21 allozyme loci were examined, of which five loci were found to be polymorphic. The overall diversity level in the examined markers was comparable to that observed in a closely related char species, Dolly Varden. The estimates of interpopulation genetic differentiation were highly statistically significant in most of the pairwise comparisons amongthe samples. The overall evaluation of the spatial genetic differentiation in white-spotted char constituted F(ST) = 0.203 and R(ST) = 0.202. Cluster analysis and multidimensional scaling based on microsatellite allele frequencies indicated the possible subdivision of the examined samples into two main groups, i.e., northern (represented by the regions of the north of Khabarovsk krai, Kamchatka, Yama Bay) and southern (with regions including Sakhalin, Primorye, and the Kuril Islands). The allozome data demonstrated a similar pattern of differentiation. The level of intra- and interpopulation genetic diversity in the southern group was higher than in the northern group. The isolation-by-distance test did not identify a significant correlation between genetic and geographic distances among the samples. The data obtained enabled the suggestion that the genetic structure of the population of white-spotted char was shaped by the influence of historical geological climatic rearrangements of its range and the genetic drift, because of determined by relatively low population number and limited in the extent of the migration activity of its anadromous form.