[Microsatellite loci variation and investigation of gene flow between two karyoforms of Cricetulus barabensis sensu lato (Rodentia, Cricetidae)].

We examine the diversity of six microsatellite loci and partial RAG1 exon of "barabensis" and "pseudogriseus" karyoforms in Cricetulus barabensis sensu lato species complex. A total of 435 specimens from 68 localities ranging from Altai to the Far East are investigated. The results of the population structure analysis (factor analysis and NJ tree based on Nei genetic distances) support subdivision into two well-differentiated clusters corresponding to the two karyoforms. These karyoforms are also well differentiated by the level of microsatellite variability. In several "barabensis" specimens, we found microsatellite alleles that are common in "pseudogriseus" populations but are otherwise absent in "barabensis." Most of these specimens originate from a single population in one of the zones of potential contact between karyoforms, Kharkhorin in Central Mongolia. These molecular results are consistent with previously published karyological data in suggesting that rare hybridization events between the two chromosomal races occur in nature.

[Features of the B chromosome in Korean wood mice Apodemus peninsulae (Thomas, 1906) from Transbaikalia and the Far East identified by the FISH method].

Korean field mice (Apodemus peninsulae) are widely distributed throughout northeastern Asia, including the Russian Far East, northern China, the Korean peninsula, Sakhalin, and Hokkaido. This mouse species is characterized by a high frequency of animals with B chromosomes differing in their number, morphology, and DNA composition in different geographical regions. For the first time a comparative analysis of DNA probes from B chromosomes with metaphase chromosomes of mice from Transbaikalia, the Far East (including the Russian Far East), Japan, and South Korea was conducted by in situ hybridization. B chromosomes in mice from the Russian Far East were shown to exhibit low variability in DNA content; however, the DNA composition of B chromosomes in species from Transbaikalia and Japan were highly variable. B chromosomes in A. peninsulae from the South Korean population demonstrate minor differences from those from the Russian Far East. We discuss the origin of B chromosomes in the studied region in comparison with previously obtained data for mice from Siberia and the Baikal region, as well as the dispersal routes of the Korean field mouse.

[Diversity of the mitochondrial DNA cytochrome B gene of the field mouse Apodemus Agrarius Pallas, 1771 in the south of the Russian far east].

We studied the variability of a fragment of the cytochrome b gene and the corresponding amino acid sequence of the field mouse Apodemus agrarius (Pallas, 1771) in the South of Primorskii krai (Far East of Russia). A significant polymorphism of these traits was detected. High indices of molecular diversity were obtained. The topology of the phylogenetic tree and the median networks suggest that the population of field mice in the south of Primorskii krai originated from three maternal lines. It was noted that clustering of haplotypes on a territorial basis is absent, and the field mouse population in southern Primorskii krai can be considered as one of the key points in maintaining a high genetic diversity of the species.

[Genetic diversity and phylogenetic relationships of the Manchurian zokor Myospalax psilurus (Rodentia, Muridae) according to RAPD-PCR analysis].

The population structuring and low genetic diversity of the Manchurian zokor Myospalax psilurus Milne-Edwards, 1874, an East Asian endemic included in the Red List of Russia, were demonstrated. Two separate geographical groups differing in the level of their genetic diversity were found on the territory of the Primorskii krai. The subpopulation located closest to the main area of this species was determined as ancestral. A subspecies differentiation of the Primorskii krai and Transbaikal M. psilurus populations was shown, as was the monophyletic origin of M. psilurus and its high divergence from M. aspalax. The animals from northern localities are recommended for reintroduction in nature under species recovery programs in Primorskii krai.

[Genetic diversity and phylogenetic relationships in the zokor subfamily Myospalacinae (Rodentia, Muridae) inferred from RAPD-PCR].

Zokors (Myospalacinae) is a group of rodents specialized for underground life, endemics of eastern Asia, which is taxonomically and evolutionarily poorly studied. We examined genetic diversity and phylogenetic relationships among zokors (Myospalax myospalax, Myospalax aspalax, Myospalax armandii, Myospalax psilurus, Myospalax smithii) using RAPD-PCR. The subfamily Myospalacinae was shown to be monophyletic and contain four evolutionary branches: M. myospalax, M. aspalax-M. armandii, M. smithii and M. psilurus. Genetic differences and high differentiation were found among the species and between two geographic forms of Manjurian zokor M. psilurus from the marginal parts of the range, Transbaikalia and Primorye. The psiluris phylogroup was shown to be dichotomically divided into two clades according to the geographical distribution of animals from Transbaikalia and Primorye. The genetic differentiation between the geographic forms of M. psilurus corresponded to the differentiation between morphologically similar species M. aspalax and M. armandii. M. armandii is a sister taxon with regard to M. aspalax. This new evidence on the evolutionary relationships among zokors does not contradict the traditional views inferred from morphological, karyological, and allozyme data, on isolation of M. myospalax and the character of form development in this group. The species status of Myospalax psilurus Milne-Edwards, 1874, M. epsilanus Thomas, 1912, M. armandii Milne-Edwards, 1867, which had been suggested earlier on the basis of biochemical and karyological data, was confirmed.

[Gene-geographical variation and genetic differentiation in red-backed voles of the genus Clethrionomys (Rodentia, Cricetidae) in the Okhotskii region]. / Genogeograficheskaia izmenchivost' i geneticheskaia differentsiatsiia lesnykh polevok roda Clethrionomys (Rodentia, Cricetidae) Priokhot'ia.

Thirteen enzyme systems and three nonenzyme proteins were electrophoretically analyzed in red-backed voles of the genus Clethrionomys. In total, 25 loci were interpreted. Gene-geographic variation was studied and indices of genetic variability and differentiation were determined. By the distribution of electrophoretic variants of hemoglobin, C. rutilus was shown to be divided into two geographical groups (northern and southern). A low level of genetic differentiation was revealed in the island isolates of C. rutilus and C. rufocanus. Separation of C. rufocanus, C. rex, and C. sicotanensis into a superspecies complex was confirmed. A study of differential G- and C-banding on C. rutilus and C. rufocanus chromosomes did not reveal intraspecific variation of autosomes. In these species, karyotypes of voles from Kamchatka Peninsula were studied for the first time. They appeared to be morphologically similar to the karyotypes continental voles by both autosomes and sex chromosomes.

[Chromosomal variability of the field mouse Apodemus agarius (Rodentia, Muridae)]. / Khromosomnaia izmenchivost' polevoi myshi Apodemus agarius (Rodentia, Muridae).

Chromosome sets of 114 Apodemus agrarius mice from 29 localities in Moldova, Ukraine, Siberia, and Far East were studied by means of G-, C-, and NOR-banding. In all populations studied, the Y chromosome was shown to be a medium-size acrocentric chromosome consisting of heterochromatin. Chromosome polymorphism observed in populations from Primorskii krai concerned (1) the morphology of the first two autosome pairs (variants A/A, A/ST, and ST/ST), (2) the number of metacentric chromosomes (from 6 to 8), and (3) heterochromatin localization in the pericentromeric regions of two metacentric chromosome pairs. A karyotype with an additional heterochromatic microchromosome found in all the metaphases studied was described in one mouse from a locality of western Primorye that has not been studied previously. In the karyotype of 15 mice from four populations of Primorye, the pool of nucleolus organizer regions is distributed over three autosome pairs rather than over four, as is the case A. agrarius from Europe. Based on the analysis of literature sources and our own data, the problem of chromosome polymorphism in the field mouse is discussed.

[Chromosome variation and anomalous karyotypes in the red-backed mouse Clethrionomys rufocanus (Rodentia, Microtinae)]. / Khromosomnaia izmenchivost' i anomal'nye kariotipy u krasno-seroi polevki Clthrionomys rufocanus (Rodentia, Microtinae).

G-banding and C-banding of chromosomes were studied in populations of the red-backed mouse Clethrionomys rufocanus from 11 localities of eastern Russia. Intrapopulation polymorphism of autosome 3 caused by the deletion-duplication of the short-arm heterochromatin (2n = 56; NFa = 56-58) was demonstrated. The karyotype of Cl. rufocanus from continental populations and Sakhalin Island was shown to have a large subtelocentric chromosome of pair 3 (NFa = 58), whereas in the population from Kunashir Island, chromosomes of this pair were acrocentric (NFa = 56). One animal from the population of the Kedrovaya Pad' Reserve (Primorsk krai) had a pericentric inversion (acrocentric morphology) of the Y chromosome. In two animals, a female from the Ussuriiskii Reserve (Primorsk krai) and a male captured near the Tomari Settlement (Sakhalin Island), a pericentric inversion of one chromosome of pair 6 was found (NFa = 59). The inversion detected in the animal from the Sakhalin population was accompanied by the loss of the centromeric heterochromatin. In contrast, the inversion of the chromosome pair 6, which was found in the mouse from the Primorsk krai population, did not involve the loss of centromeric heterochromatin. Analysis of our results and data from the literature showed that the karyotype of Cl. rufocanus is not constant, as was thought earlier. The percentage of animals with abnormal karyotype (1.6%) was higher than in other groups of red-backed mice studied (0.12-0.7%).

[Genetic differentiation of Caucasian wood mice: comparison of isozymic, chromosomal and molecular divergence]. / Geneticheskaia differentsiatsiia lesnykh myshei Kavkaza: sravnenie izozimnoi, khromosomnoi i molekuliarnoi divergentsii.

Data on the complex genetic analysis of three sympatric species of Caucasian wood mice, Apodemus ponticus, A. fulvipectus, and A. uralensis are presented. A high degree of genetic differentiation at the isozymic, karyological and molecular (nuclear DNA) levels was revealed. The genetic distances between each pair of species varied significantly within a wide range depending on the analyzed level of the organization of genetic material. Mean values of genetic divergence from one species to another were also variable. These findings indicated that evolution of chromosomes was slower than that of isozymes, and the degree of species divergence was similar on cytogenetic and molecular levels. They also suggested that the rates of species evolution could vary in different phyletic lineages and on different levels of organization. Some phyletic lineages of Apodemus could be distinguished by different directions of evolution.