Complete mitochondrial genome of the yellow-spotted grayling Thymallus flavomaculatus (Salmoniformes, Salmonidae).

The complete mitochondrial genome was sequenced in two individuals of yellow-spotted grayling Thymallus flavomaculatus. The genome sequences are 16,659 bp in size, and the gene arrangement, composition and size are very similar to the salmonid fish genomes published previously. The low level of sequence divergence detected between the genome of Th. flavomaculatus and the GenBank complete mitochondrial genomes of the Th. yaluensis (KJ866484) and Th. grubii (KF649073) may likely be due to recent divergence of the species and/or historical hybridization and interspecific replacement of mtDNA.

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

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.

[Genetic divergence of chars of the genus Salvelinus from Kronotsky Lake (Kamchatka Peninsula)].

Chars from the genus Salvelinus, inhabiting lakes and lake-river systems, belong to morphologically and ecologically different forms whose taxonomic status is under dispute. In the present work, we have examined genetic variation and divergence in various chars from the Kronotsky lake basin: the lacustrine chars (white, nose, and long-head) and Dolly Varden char Salvelinus malma. The study was conducted using analysis of allozyme and microsatellite loci, myogens, RAPD, and restriction analysis of two mtDNA segments. The estimates of heterozygoisty at allozyme and microsatellite loci were similar to the corresponding parameters in populations of northern Dolly Varden and Arctic char. Heterozygote deficit was recorded in both samples of individual forms, and in the combined sample of all chars from Kronotsky Lake. For both markers, appreciable genetic differentiation among the samples of different char forms was found, which was comparable to that among the spatially isolated populations of northern Dolly Varden. This result indicates reproductive isolation among the char forms examined. However, this isolation is not complete, because no fixed differences between the forms by any of the genetic systems analyzed was found. The genetic differentiation among different forms of lacustrine chars, which corresponds to the interpopulation rather than interspecies level, is thought to be explained by their comparatively recent divergence.

[Far Eastern mullet Mugil soiuy Basilewsky (Mugilidae, Mugiliformes): the genetic structure of populations and its change under acclimatization]. / Dal'nevostochnyi pilengas Mugil soiuy Basilewsky (Mugilidae, Mugiliformes): geneticheskaia struktura populiatsii i ee izmeneniia pri akklimatizatsii.

The introduction of Far Eastern mullet (pilengas) in the Azov Sea in the 1970s-1980s has resulted in the formation of a self-reproducing commercial population. We have carried out a comparative population-genetic analysis of the mullet from the native (Primorye, the Sea of Japan basin) and the new (The Azov Sea basin) ranges. Genetic characteristics of three Primorye and three Azov local samples were studied using electrophoretic analysis of 15 enzymes encoded by 21 gene loci. In the Azov mullet, the initial heterozygosity characteristic of the donor population was preserved while the genotype and the allele compositions changed; the changes included a 1.9-fold reduction in the percentage of polymorphic loci and 1.5-fold reduction in the mean number of alleles per locus. The genetic differences between the Azov and the Primorye sample groups were highly significant. In the native range, no genetic differentiation among the mullet samples from different areas was found (Gst = 0.42%), whereas in the Azov Sea basin, the samples from spatially isolated populations (ecological groups) exhibited genetic differences (Gst = 1.38). The genetic divergence of the subpopulations and the excess of heterozygotes at some loci in the Azov mullet suggest selection processes that formed genetically divergent groups associated with the areas of different salinity in the new range. The salinity level is assumed to be the most probable factor of local differentiating selection during fast adaptation and naturalization of the introduced mullet.