[Composition and distribution of the mitochondrial lineages of gray whales (Eschirichtius robustus) in the far eastern seas of Russia].

The frequency of occurrence of the mitotypes (control region, cytochrome b gene, and DN2 gene) has been studied for groups of gray whales feeding and growing along Chukotka Peninsula, Koryak Coast, eastern Kamchatka, and Sakhalin Island. The number of the mitotypes decreased dramatically from the northern waters southwards; however, the dominant mitotypes remained the same. Both mitochondrial lineages known for this species might be found for the whales gathering in the reproductive area along the Californian Coast in accordance with the comparison of the published and original data on the haplotypes of the control region.

[Genetic structure of sable (Martes zibellina L.) from Eurasia based on distribution of mitochondrial lineages].

The phylogeography of the sable, which is a commercially valuable species, is extremely complicated and poorly investigated. Specifically, the effects of factors such as the range dynamics of the sable during the Pleistocene Epoch, the localization of glacial refugia, species distribution pattern in Holocene, and recent dramatic population decline, along with massive reacclimatization measures, on the species phylogeography remain unclear. Based on the sequence analysis of the control region of mitochondrial DNA from sables that inhabit different parts of the species range, a suggestion was made of the considerably high Pleistocene genetic diversity in sable, which was subsequently lost.

[The mountain weasel Mustela kathiah (Carnivora: Mustelidae): molecular and karyological data].

The karyotype of Mustela kathiah was first described. Its structure is most similar to the karyotype of M. altaica, differing inthe morphological peculiarites of five pairs of large chromosomes.

[Karyotypes divergence in superspecies complex Cricetulus barabensis sensu lato and their interrelationships in natural contact zones].

Interrelationships between three chromosomal forms of striped hamsters belonging to the superspecies complex Cricetulus barabensis sensu lato (Cricetidae, Rodentia), namely 'barabensis', 'pseudogriseus', and 'griseus', are examined from the standpoint of different biological/genetic species concepts. Craniometric data suggest that differences between the karyotypes are rather of subspecies level. Cytogenetic differences between the karyotypes are also not great and correspond to the level of chromosomal races within a single species.

[Decorative forms of hamsters Phodopus (Mammalia, Cricetinae): an analysis of genetic lines distribution and peculiarities of hair changes].

Three species of dwarf hamsters (genus Phodopus, family Cricetidae) inhabit some regions of Russia, Kazakhstan, Mongolia, and China, each having quite extensive range. In recent decades, the dwarf hamsters became widely spread all over the world, initially as laboratory animals and later as popular pets. By now, there is lot of decorative breed lines and colored forms of these animals.

[Analysis of genetic diversity of the Roborovski hamster (Phodopus roborovskii) in the northern part of its habitat].

An analysis of sequences of the cytochrome b gene and control region of mitochondrial DNA of 30 Roborovski hamsters (Phodopus roborovskii; Rodentia: Cricetinae) captured at ten geographical points from Zaisanskaya Depression (Kazakhstan) in the northwest to the Shilin-Gol area (China) in the southeast was conducted. The absence of a connection between the similarity of the discovered haplotypes and their geographical distribution allows us to assume that the modern genetic diversity of the species on the studied territory formed owing to migration waves from more southern areas.

[Genetic analysis of sympatric sable (Martes zibellina) and Marten (M. martes) populations in the northern urals].

Analysis of nucleotide sequences of the mitochondrial DNA (mtDNA) control region (495 bp) of sables (Martes zibellina) and martens (M. martes) from allopatric parts of the species ranges has shown a considerable interspecific genetic distance (3%). In sympatric populations of these species in the northern Urals, differences between two species-specific mtDNA lineages are still large; however, classification of each individual nucleotide sequence with one of the two lineages is not correlated with whether the given animal is phenotypically a sable, a marten, or a potential hybrid (the so-called kidas).

[Molecular genetic study of the beluga (Delphinapterus leucas: Cetacea, Monodontidae) summering in the southern Sea of Okhotsk as compared to North American populations].

The structure of the left part of the mtDNA control region has been studied in Delphinapterus leucas captured in summer in the southern Sea of Okhotsk. The data have been compared with published results of similar studies on D. leucas at different sites along the American coast.

[Nitrogen requirements of Microtus rossiaemeridionalis].

Total nitrogen requirements in the small herbivorous rodent Microtus rossiaemeridionalis were studied. When provided with two kinds of standard laboratory food (about 20 and 0% digestible protein, respectively) ad libitum (cafeteria diet), the voles chose a diet of 14% protein. The total daily (with urine and faeces) nitrogen losses were, in this case, determined as 3.

[Effect of deficiency of dietary nitrogen on cellulose digestibility and nitrogen-fixing flora activity in the sibling vole Microtus rossiaemeridionalis].

The effect of food composition on nitrogen-fixing activity of the symbionts living in the digestive tract of the sibling vole Microtus rossiaemeridionalis was experimentally studied. In the control, the rodents were allowed to select any of three food mixes: protein-rich, protein-free with low cellulose content, and protein-free with high cellulose content. The voles consumed the food in a proportion corresponding to 16% of protein and about 6% of cellulose.

[Water and energy metabolism in representatives of the genus Martes and Mustela (Mammalia: Mustelidae)].

The quantities of consumed food and water, quantity and moisture content of faeces, as well as quantity and concentration of excreted urine were determined in representatives of Martes--marten (M. martes) and sable (M. zibellina)--as well as in polecat (Mustela putorius).

[Nitrogen fixation--new fenomenon in rodent feeding].

We have conducted a series of experiments in order to test hypothesis about the possible use of nitrogen fixation by small phytophagous mammals as a way to supplement their nitrogen balance. Two groups of red voles Clethrionomys rutilis were kept on rations with different protein nitrogen content. Three days later, the rate of nitrogen fixation was determined in different regions of the digestive tract.

[The characteristics of water metabolism and the resistance to dehydration of representatives of the family of mustelids (Carnivora: Mustelidae)].

Food consumption, total water intake, urine volume and concentration, and water content in feces were determined under the conditions of free access to drinking water and in its absence in some mustelids that inhabit territories with different water accessibility: Mustela putorius, M. eversmanni, M. lutreola, and M.

[A comparative study of the osmoregulating system in the hamsters Phodopus roborovskii and Phodopus sungorus].

The hamster Phodopus roborovskii is adapted to live in desert, Phodopus sungorus in less arid regions. Hamsters of both species have rather close values of blood serum osmolality and ion concentration, after dehydration the value of urine osmolality is found to be equally high. The microdissection of the kidney did not reveal any difference in the structure and arrangement of nephrons in cortex and medulla.

[The functional capacities of the kidneys in hamsters of the genus Phodopus].

Studies have been made on total osmolarity and concentration of Na and K in the urine, as well as on the level of diuresis in three species of the hamsters (Phodopus sungorus, Ph. campbelli, Ph. roborovskii) under the conditions of presence or absence of wet food and during water and salt loading.