[Cytogenetics of albinism in polecats of the genus Putorius (Carnivora, Mustelidae)]. / Tsitogenetika al'binizma u khor'kov roda Putorius (Carnivora, Mustelidae).

Karyotypes of two ferret species, Putorius eversmanni (2n = 38) and P. putorius (2n = 40), differ in a single Robertsonian rearrangement, resulting in decreased chromosome number in P. eversmanni. Interspecific hybrids from crosses between P. eversmanni and domesticated albino ferret P. putorius furo are fertile. Hybrid individuals have a chromosome set 2 = 39. Analysis of offspring from crosses of these hybrids showed that albinism is a recessive character. Offspring obtained from crosses between interspecific hybrid ferrets and between these hybrids and parental species was subjected to chromosome analysis. A statistically significant correlation was observed between the chromosome number and albinism. As a rule, albino hybrids have a chromosome number 2n = 40. This suggests that the locus, controlling albinism, is located at one of the two pairs of acrocentric chromsomes involved in Robertsonian rearrangement. The rare occurrence of albino hybrids with 2n = 39 may be attributed to recombination. According to our data, recombination probability is less than 0.5 which indicates that the albinism locus located near the centromere. Possible extrapolation of the data obtained for ferrets to other Mustelidae is discussed.

[Phylogenetic relations of closely related species of Mustelidae. Interspecies variability of localization of restriction sites of BamHI-repeats]. / Filogeneticheskie otnosheniia blizkorodstvennykh vidov semeistva kunitseobraznykh. Mezhvidnaia izmenchivost', lokalizatsii restriktsionnykh saitov BamHI-povtorov.

The patterns of blot-hybridization of cloned BamHI repeats to genome DNAs were applied for estimation of phylogenetic relationships of closely related species (Mustela (L.) lutreola, M. (P.) putorius, M. (K.) sibirica, M. (M.) erminea, M. (L.) vision, Vormela peregusna). On the basis of information about interspecific distribution of the blot-hybridization bands (+, -) of BamHI repeats, phylogenetic tree was constructed, after selection of compatible characters, which revealed essential rate ununiformity during mustelids' evolution.

[EcoRI- and BamHI-families of repeated sequences in mustelids]. / EcoRI- i BamHI-semeistva povtorov kunitseobraznykh.

The restriction enzymes EcoRI and BamHI digest the genomic DNAs from six mustelids species Mustela lutreola, M. vision, M. erminea, M. sibirica, Vormela peregusna, producing repeated fragments varying in length. Some fragments were hybridized to chromosomes and restriction digests of DNAs from some mustelids and other mammals. The 0.7 kb EcoRI repeats from DNA of M. erminea are dispersed over chromosomes of carnivors. The 1.35, 1.9 and 2.7 kb BamHI repeats from DNA of polecat M. putorius furo are specific for mustelids. These repeats demonstrate interspecific variation in length and the number of copies. All BamHI repeats have no strict tandem organization. The 1.9 kb BamHI repeats are concentrated in the heterochromatic pericentromeric regions and additional chromosome arms. The 1.35 kb BamHI repeats are only located in the centromeric regions of chromosomes of five species and are absent in Vormela peregusna.

[Effect of cryopreservation on the morphology of blastocysts of the ferret Mustela eversmanni]. / Vliianie kriokonservatsii na morfologiiu blastotsist svetlogo khor'ka Mustela eversmanni.

In this study, we have undertaken an attempt to use the technique of cryopreservation of a mustelid embryo-sing Mustela eversmanni as the experimental model. Ferret blastocysts were frozen with glycerol or DMSO. Characteristic feature of blastocyst morphology, as well as changes in their ultrastructure after freezing and cryopreservation have been examined by techniques of light and electron microscopy. When glycerol was used, damage of ferret blastocysts induced by freezing was more significant than with DMSO as a cryoprotector. In all cases, structural alterations in inner cell mass after cryopreservation were much more significant than in the cells of the trophoblast. We discuss possible use of cryopreservation of embryos for the conservation of Mustelid species.

[Superovulation induced by the administration of PMSG to mustelids]. / Superovuliatsiia, vyzvannaia vvedeniem GSZhK u kunitseobraznykh.

In this paper, we have attempted to use the technique of superovulation in mustelids. Ermine (Mustela erminea) and several species of ferret (Mustela eversmanni, Mustela putorius, Mustela putorius furo [correction of hamster (Putorius eversmanni, Putorius putorius, Putorius putorius furo)] have been used as experimental models. We have conducted a detailed study of superovulation and early embryonic development in animals of these species treated with PMSG [correction of GPMS]. We have shown that superovulatory response is produced only in the right, but not in the left ovary of hormonally treated animals. Embryonic development in hormonally stimulated animals was accelerated as compared with animals that were reproducing under natural conditions. Perspectives and limitations in the use of hormonal treatment with the purpose to induce superovulation in mammals are discussed.

[The preimplantation embryonic development of 2 species of mammals from the family Mustelidae (Mustela erminea and Mustela vison)]. / Doimplantatsionnoe razvitie zarodyshei dvukh vidov mlekopitaiushchikh iz semeistva kunitseobraznykh (Mustela erminea i Mustela vison).

The preimplantation development of common weasel and American mink embryos was studied using light microscopy. Oocytes and blastomeres of these embryos are rich with lipids synthesized during oogenesis. Apparently, most lipids are utilized during the trophoblast formation. Large spherical blastomeres protecting zona pellucida are formed by the stage of implantation. The shape of the blastocyst, as well as central superficial implantation, are typical for carnivores and distinguish the studied order from other ones (e.g., from rodents or artiodactyls). Several aspects of evolution of mammals are discussed. A suggestion is made that differences between orders in the shape of the blastocyst and ways of their implantation reflect poly-phyletic origin of mammals.

[Reproductive physiology of the European mink: progesterone profile during pregnancy].

Reproductive physiology of the European mink, an endangered mustelid species, has been so far scarcely investigated. This study confirms that in European mink embryo implantation occurs on the day 12 of pregnancy. Progesterone profile during pregnancy has been compared in European mink and domestic ferret. In both species, progesterone increases at peri-implantation period, i. e. on day 8 and day 12 after mating. However, toward the end of pregnancy, on day 40 after mating, progesterone concentration in faeces of the ferrets decreases and does not differ from the initial level. In contrast, increase of progesterone during first 12 days of pregnancy in European mink is not as rapid as in ferrets, but in this species, there is no visible decrease of progesterone at the end of pregnancy. Peak levels of progesterone in faeces (day 8, 12) are lower in European mink than in ferret.