[Phylogeny of charrs of the genus Salvelinus based on mitochondrial DNA data].

Charrs of the genus Salvelinus (including Salvethymus) represent a monophyletic group of salmonid fishes that diverged from the common ancestor without subdivision into subgenera. The phylogenesis of the genus is characterized by four cycles of mitochondrial genome divergence. The first one, belonging to the Late Miocene--the border between Miocene and Pliocene (6 to 4 million years ago)--was associated with the consecutive divergence of the S. fontinalis, S. namaycush, S. levanidovi, and S. leucomaenis basal branches. Two divergence events, including separation of the ancestral lineage of western Pacific group of S. m. krascheninnikovi and the following segregation of the common ancestor into two mitochondrial phyla, happened within the period of 3 to 2 million years ago. The next cycle is attributed to the time interval of about 1 million years ago and includes the divergence of both phyla. In one phylum, a relatively quick isolation of Arctic and eastern Pacific phylogroups, along with the divergence of the latter phylogroup into S. confluentus and S. m. lordi lineages, took place. At the same time, the second phylum diverged into the S. m. malma and S. alpinus phylogenetic groups. At the final stage (Middle to Late Pleistocene), differentiation of the taxa within the phylogenetic groups took place.

[Genetic Differentiation of Pacific Smelt Osmerus mordax dentex Inferred from the Data of Mitochondrial DNA Analysis].

The population genetic structure of Pacific smelt Osmerus mordax dentex from 25 locations in the Sea of Japan, Okhotsk Sea, Bering Sea, Kara Sea, Barents Sea, and White Sea was examined based on mitochondrial DNA variability. The genetic structuring of O. m. dentex over the larger part of the examined Eurasian range was weakly expressed, despite the high level of haplotype diversity (0.770 +/- 0.154). Hierarchical analysis of molecular variance (AMOVA) showed that the majority of molecular diversity (89%) was found within the populations. The most considerable differentiation of geographical populations for those grouped by their association with sea basins was observed for the Sea of Japan; with mean phi(ST) values of 0.114 (based on data from restriction fragment length polymorphism (RFLP) analysis) and 0.115 (based on sequencing data) (p < 0.01).

[Intraspecific polymorphism of mtDNA in Sakhalin taimen Parahucho perryi].

The intraspecific polymorphism of Sakhalin taimen Parahucho perryi (Brevoort, 1856), Salmonidae, was assessed via the RFLP analysis of mitochondrial DNA fragments that contain Cytb, the control region (D-loop), and the genes for the NADH dehydrogenase subunits 1-4, as well as the sequencing of the mitochondrial DNA COI gene. The statistically significant differentiation of the populations from the mainland coast of the Sea of Japan and the eastern and western coasts of Sakhalin Island was demonstrated. The higher level of haplotype diversity in Sakhalin populations compared to Primorye populations and the structure of haplotype genealogies suggested that all populations of Parahucho perryi originated from a common ancestor, which probably lived on the western coast of the Sakhalin Island.

[Population genetic structure of northern Dolly Varden char Salvelinus malma malma in Asia and North America].

The level of genetic differentiation of northern Dolly Varden char Salvelinus malma malma from Asia and North America was evaluated using the data on mtDNA variation (regions ND1/ND2, ND5/ND6, and Cytb/D loop) obtained by means of PCR-RFLP analysis. For S. m. malma, the mean values of haplotype and nucleotide diversity were 0.5261 +/- 0.00388 and 0.001558, respectively. The mean estimate of the population nucleotide divergence constituted 0.055%. It was demonstrated that S. m. malma on the most part of the species range examined (drainages of the Beaufort Sea, Chukotka Sea, Bering Sea, and the Sea of Okhotsk) was characterized by the population genetic structure with the low level of genetic differentiation and divergence. At the same time, populations from the Pacific Ocean Gulf of Alaska demonstrated marked genetic differentiation, supported by the high pairwise phi(ST) values (from 0.4198 to 0.5211) and nucleotide divergence estimates (mean divergence, 0.129%), from Asian and North American populations. Nested analysis of molecular variance (AMOVA) showed that most of the mtDNA variation in S. m. malma fell in the intrapopulation component (72.5%). At the same time, the differences between the populations (21.1%) and between the regions (6.4%) made lower contribution to the total variation.

[Genetic divergence and relationships among smelts of the genus Osmerus from the Russian waters].

Smelts of the genus Osmerus, O. eperlanus and O. mordax dentes, inhabiting the basins of the Atlantic, Arctic, and Pacific oceans were investigated using RFLP analysis of the mitochondrial DNA segments A8/A6/COIII/ND3 and ND3/ND4, and sequencing of the cytb and COI genes (mtDNA), and intron 1 of the rpS7 gene (nDNA). A total of 14 samples from the populations from most part of the Russian range were examined. The mean values of haplotype and nucleotide diversity constituted 0.5997 +/- 0.11264 and 0.003201 for O. m. dentex, and 0.3086 +/- 0.09892 and 0.000431 for O. eperlanus, respectively. The high level of interspecific diversity (12.94%) along with the low level of intraspercific diversity (0.049% for O. m. dentex, and 0.001% for O. eperlanus was observed. The dendrograms (UPGMA, NJ, MP, and BA) constructed using the data of RFLP analysis of mtDNA, along with the sequencing data of mitochondrial and nuclear genes were congruent. The representatives of O. eperlanus and O. m. dentex formed steady clusters in accordance with their species affiliation, albeit without subdivision into local populations depending on their geographic locality.

[Genetic divergence of mitochondrial DNA in white char Salvelinus albus and northern Dolly Varden char Salvelinus malma malma].

Comparative analysis of mitochondrial DNA variation was performed in white char Salvelinus albus and in its putative ancestor species, northern Dolly Varden char Salvelinus malma malma. Highly statistically significant differentiation of S. albus and S. m. malma in the areas of sympatric (Kamchatka River basin) and allopatric (Kronotskoe Lake and Kronotskaya River) residence was demonstrated. The mtDNA divergence between S. albus and S. m. malma did not exceed the range ofintraspecific variation in the populations of northern Dolly Varden char. At the same time, clusterization pattern of the Salvelinus chars provides hypothesis on the common origin of two allopatric populations of white char. Genealogical analysis of haplotypes indicates that S. albus and S. m. malma currently demonstrate incomplete radiation of mitochondrial lineages. The low nucleotide divergence estimates between S. albus and S. m. malma reflect the short time period since the beginning of the radiation of ancestral lineages. These estimates are determined by ancestral polymorphism and haplotype exchange between the diverged phylogenetic groups as a result of introgressive hybridization.

[Phylogeography of southern Asian Dolly Varden char Salvelinus malma krascheninnikovi: genealogical analysis of mitochondrial DNA].

Phylogeography of southern Asian Dolly Varden char was studied using the data on mtDNA variation (regions ND1/ND2, ND5/ND6, and Cytb/D loop) obtained using PCR-RFLP analysis. Analysis of contemporary population genetic structure showed that S. m. krascheninnikovi throughout the whole species range was characterized by high population differentiation in combination with rather small differences between the populations from remote regions. The genealogy of mtDNA haplotypes was reconstructed and nested clade analysis of geographical distances was performed. Geographical distribution of mtDNA haplotypes of S. m. krascheninnikovi was explained by population genetic processes (restricted gene flow), as well as by historical demographic events (range expansion and fragmentation). It was demonstrated that the main demographic events were associated with cyclic processes of the geological formation of the Sea of Japan and adjacent territories. Furthermore, genealogical tree of S. m. krascheninnikovi contained the traces of secondary contact between isolated phylogeographical lineages.

[Phylogenetic analysis of smelts (Osmeridae) based on the variation of cytochrome b gene].

Putative phylogenetic relationships between all smelt species inhabiting Russian waters were studied using RFLP and the data on divergence between nucleotide sequences of the mitochondrial gene encoding cytochrome b. All types of phylogenetic trees (NJ, MP, and Bayesian) displayed stable clustering into isolated groups corresponding to the division of the subfamily Osmerinae into three genera, Mallotus, Osmerus, and Hypomesus. It was demonstrated that the Mallotus phylum was the first to diverge from a hypothetical common ancestor of the smelts. Later, it divided into two clusters corresponding to the modern subspecies Mallotus villosus villosus and M. v. catervarius. The phylum of the genus Osmerus diverged later than the genus Mallotus and also divided into two clusters, one including O. mordax of the Pacific (Sea of Japan) and Arctic (Kara and Barents Seas) basins and the other, anadromous and resident ecotypes of the O. eperlanus from the Baltic Sea basin. The smelts of the genus Hypomesus is the youngest phylogenetic group among the taxa studied; it forms three individual clusters matching the species H. olidus, H. nipponensis, and H. japonicus. The proposed phylogenetic hypothesis is discussed from the standpoint of its compliance with the phylogenetic constructions based on the external morphological and osteological traits.

[Erratic divergent evolution in fish from the Northern Pacific].

The mtDNA divergence was examined in some families of anadromous and semi-anadromous fish. Heterogeneous distribution of the divergence values along the scale was demonstrated. Statistically significantly higher number of the species pairs were characterized by divergence values ranging from 2 to 4% and 5 to 12% of nucleotide substitutions. These results suggest that in different monophyletic groups occupying common historical ranges, divergence-associated speciation often happened within similar time intervals. Comparison of the species divergence time calculated using the molecular clock pointed to the coincidence of the radiation periods in the taxa with paleogeological and paleoclimatic global changes in the history of Northern Pacific.

[Phylogenetic relationships of Sakhalin taimen Parahucho perryi inferred from PCR-RFLP analysis of mitochondrial DNA].

RFLP analysis of three amplified mtDNA fragments (Cytb/D-loop, ND1/ND2, and ND3/ND4L/ND4) was performed in the following taxa: Parahucho perryi, Hucho taimen, Brachymystax lenok, B. tumensis, Salmo salar, Salvelinus leucomaenis, and S. levanidovi. For mtDNA of P. perryi, a substantial decrease in the haplotype and nucleotide diversity was observed as a result of random genetic drift, caused by a reduction in the effective population size. Nucleotide divergence estimates between the mtDNA haplotypes were determined. Sakhalin taimen P. perryi was found to be approximately equally diverged from S. salar and from the charrs of the genus Salvelinus, by 11.0 and 10.0%, respectively. The divergence between P. perryi and H. taimen constituted 14.6%, between P. perryi and lenoks of the genus Brachymystax, 14.2%, and between H. taimen and Brachymystax, 7.7%. The analysis of possible phylogenetic relationships of the mtDNA from P. perryi among the group of taxa examined confirmed validity of the genus Parahucho. Phylogenetic reconstructions performed showed that robustness of the trees constructed for the complex of phylogenetically informative characters over three mtDNA fragments was considerably higher than that of the trees constructed for individual genes.

[Mitochondrial DNA variation in Pacific capelin (Mallotus villosus catervarius) from the Sea of Okhotsk, inferred from PCR-RFLP analysis].

Four population samples of Pacific capelin Mallotus villosus catervarius (Pennant, 1784) from geographically distant localities in the Sea of Okhotsk, Tauy Bay and the eastern coast of the Sakhalin Island, were examined using PCR-RFLP analysis of three mitochondrial DNA regions (A8/A6/COIII/ND3, ND3/ND4L/ND4, and ND5/ND6). The nucleotide divergence of mtDNA sequences among the samples, as well as the analysis of geographic heterogeneity of the haplotype frequencies and quantitative estimation of genetic differentiation performed by means of AMOVA, showed that the samples examined belonged to one panmictic population. Genealogic analysis of the mtDNA variation structure was carried out. It was demonstrated that the high level of haplotype diversity (0.9639 +/- 0.00015) along with the low level of nucleotide diversity (0.003818 +/- 0.0000003) pointed to the exponential rate of population growth of the capelin from the Sea of Okhotsk, which rather recently in its evolutionary history faced the bottleneck effect.

[Genetic divergence of sympatric charrs of the genus Salvelinus from Nachikinskoe Lake (Kamchatka)].

We studied genetic differentiation of two charr species, Dolly Varden Salvelinus malma malma Walbaum and resident lacustrine charr Salvelinus sp., which sympatrically inhabit Nachikinskoe Lake (the Bol'shaya River basin) in southwestern Kamchatka Peninsula. Using restriction analysis (RFLP), three mitochondrial DNA fragments (ND1/ND2, ND5/ND6, and Cytb/D loop) amplified in polymerase chain reaction (PCR) were compared. The divergence of the mtDNA sequences between Salvelinus sp. and S. malma malma was 2.8%; Salvelinus sp. and S. taranetzi, 0.36%; Salvelinus sp. and S. krogiusae, 0.21%; Salvelinus sp. and S. alpinus, 3.0%. These results point to reproductive isolation of charrs in Nachikinskoe Lake and support the earlier suggestion on a close relationship between Salvelinus sp., S. taranetzi, and S. krogiusae.

[Effect of isolation on the genetic characteristics of populations in charrs of the genus Salvelinus].

To study the effect of isolation on the genetic variation of mDNA, Salvelinus malma krascheninnikovi and S. malma malma nonanadromous populations from different model ecosystems were examined by RT-PCR. The haplotype and nucleotide diversities of mtDNA were significantly decreased in three isolated populations as a result of random gene drift. The genealogy of mtDNA haplotypes was reconstructed. The formation of the modem structure of the isolated populations is discussed in terms of phylogeography.

[Differentiation of Dolly Varden char Salvelinus malma from Asia and North America inferred from PCR-RFLP analysis of mitochondrial DNA].

Genetic differentiation of Dolly Varden char Salvelinus malma Walbaum from the Asian and North American Pacific coasts was studied. We examined restriction fragment length polymorphism of three mitochondrial DNA (mtDNA) fragments amplified in polymerase chain reaction, which encoded four NADH dehydrogenase subunits, the cytochrome b gene, and a D-loop segment. The mtDNA haplotypes were shown to form three phylogenetic groups, whose geographic distribution corresponded to three Dolly Varden subspecies: S. malma malma, S. malma krascheninnikovi, and S. malma lordi. The nucleotide sequence divergence between S. malma malma and S. malma krascheninnikovi was 3.8%; between S. malma malma and S. malma lordi, 3.1%; and between S. malma krascheninnikovi and S. malma lordi, 2.5%. The northern Dolly Varden S. malma malma from Asia was shown to be genetically identical to that from North America.

[Restriction analysis of the mitochondrial genome of Salmonid fishes of the family Salmonidae]. / Restriktaznyi analiz mitokhondrial'nogo genoma lososevykh ryb semeistva Salmonidae.

Based on comparative restriction analysis of mitochondrial DNA, genetic divergence between 11 species belonging to four genera of the family Salmonidae was estimated. About 2% of the mitochondrial genome (304 np) was examined using 16 restrictases that recognize 6-nucleotide sites. Nucleotide difference estimates ranged from 0-5.17 +/- 1.07% in chars of the genus Salvelinus to 2.05 +/- 0.71%-8.64 +/- 1.14% in the Pacific salmon species of the genus Oncorhynchus. The greatest divergence was found between the genera Oncorhynchus and Parahucho (9.42 +/- 1.31%-13.08 +/- 1.24%), and between Oncorhynchus and Salvelinus (12.50 +/- 1.00%). The divergence between the Pacific salmon and trout species was equal to 8.17 +/- 1.17. The generic status of Parahucho and Parasalmo is confirmed.

[Differentiation of Salvelinus malma charr and Taranetz Charr Salvelinus taranetzi from PCR-RFLP analysis of mitochondrial DNA]. / Differentsiatsiia mal'my Salvelinus malma i gol'tsa tarantsa Salvelinus taranetzi po dannym PCR-RFLP-analiza mitokhondrial'noi DNK.

Genetic differentiation of two sympatric charr species, the Dolly Varden charr (Salvelinus malma Walbaum) and the Taranetz charr (S. taranetzi Kaganovski), has been studied. Restriction fragment length polymorphism (RFLP) analysis has been used to compare three mitochondrial DNA (mtDNA) fragments (ND1/ND2, ND5/ND6, and Cytb/D-loop) amplified via polymerase chain reaction (PCR). The divergence between S. malma and S. taranetzi inferred from mtDNA nucleotide sequences is 2.8%; between S. leucomaenis and S. taranetzi, 7.1%; and between S. malma and S. leucomaenis, 7.5%. The absence of common haplotypes and the degree of divergence indicate that the Dolly Varden charr and the Taranetz charr are genetically isolated and confirm that S. taranetzi may be regarded as a separate species.

[Genetic differentiation of three sympatric charr species from genus Salvelinus inferred from PCR-RFLP analysis of mitochondrial DNA]. / Geneticheskaia differentsiatsiia trekh simpatrichnykh vidov gol'tsov roda Salvelinus po dannym PCR-RFLP-analiza mitokhondrial'noi DNK.

We examined differentiation of three sympatric charr species Dolly Varden charr Salvelinus malma Walbaum, white-spotted charr S. leucomaenis Pallas, and Levanidov charr S. levanidovi Chereshnev, Scopetz, Gudkov. Using restriction fragment length polymorphism analysis (RFLP), three mitochondrial DNA fragments (ND1/ND2, ND5/ND6, and Cytb/D-loop) amplified in PCR were compared. The divergence of mtDNA nucleotide sequences between S. levanidovi and S. leucomaenis was about 9.7%, between S. levanidovi and S. malma, 8.7%, and between S. malma and S. laecomaenis, 7.5%. These results indicate genetic isolation of the species examined and support the earlier suggestion on closeness of Levanidov charr to the common ancestor of the genus Salvelinus.

[The divergence of the dolly varden char Salvelinus malma in Asian Northern Pacific populations inferred from the PCR-RFLP analysis of the mitochondrial DNA]. / Divergentsiia mal'my Salvelinus malma v Aziatskoi chasti Severnoi Patsifiki po dannym PCR-RFLP-analiza mitochondrial'noi DNK.

Genetic differentiation of the dolly varden char Salvelinus malma Walbaum was studied in five populations from the western part of the Northern Pacific. Using restriction analysis (RFLP), we examined polymorphism of three mitochondrial DNA (mtDNA) fragments amplified in polymerase chain reaction (PCR). MtDNA haplotypes were shown to fall into two phylogenetic groups, which probably reflect the existence of two previously described subspecies of Asian dolly varden, S. malma malma and S. malma krascheninnikovi. The divergence of mtDNA nucleotide sequences in the dolly varden subspecies (about 4%) corresponds to the differences between the valid char species from the genus Salvelinus.