Whole genome SNP scanning of snow sheep (Ovis nivicola).

This is the first report performing the whole genome SNP scanning of snow sheep (Ovis nivicola). Samples of snow sheep (n = 18) collected in six different regions of the Republic of Sakha (Yakutia) from 64° to 71° N. For SNP genotyping, we applied Ovine 50K SNP BeadChip (Illumina, United States), designed for domestic sheep. The total number of genotyped SNPs (call rate 90%) was 47796 (88.1% of total SNPs), wherein 1006 SNPs were polymorphic (2.1%). Principal component analysis (PCA) showed the clear differentiation within the species O. nivicola: studied individuals were distributed among five distinct arrays corresponding to the geographical locations of sampling points. Our results demonstrate that the DNA chip designed for domestic sheep can be successfully used to study the allele pool and the genetic structure of snow sheep populations.

[Dynamics of morphofunctional changes in aging bovine ova during the prolonged culture in vitro].

In the absence of activating stimuli, aging processes are initiated in matured mammalian oocytes, which negatively affect the quality of ova and their capacity for further development. On the model of the prolonged culture of bovine oocytes, the dynamics of a number of morphofunctional changes associated with the postovulatory aging was investigated in the present work. In cumulus-enclosed oocytes, migration of the first polar body relative to metaphase II chromosomes started between 18 and 22 h of maturation. The angle of the body deviation from the metaphase plate rose as the culture time increased to 30 h. By 32 h of culture, a gain in the rate of ova with the abnormal chromosome morphology was observed that continued up to 56 h. Furthermore, after 56 h, signs of spontaneous parthenogenetic activation were revealed in 16 percent of matured oocytes. During the prolonged culture of oocytes deprived of cumulus cells after 20 h of maturation, an increase in the frequency of chromosomal abnormalities was found only by 44 h. At the same time the cumulus elimination did not affect the maintenance of the meiosis II blockade in aging ova. Meanwhile, destructive chromosomal changes in oocytes were attended by a gradual rise in the level of apoptotic degeneration and reduction in the proliferative activity of surrounding cumulus cells. The results obtained point to the various temporal dynamics of distinct morphofunctional changes and to the participation of cumulus cells in modulation of the speed of metaphase chromosome destructive modifications in aging bovine ova.

[Role of protein kinases in prolactin signaling in bovine oocyte-cumulus complexes].

Mechanisms of prolactin signal transduction in generative and somatic cells of mammalian ovarian follicles have been studied only to a small extent. In the present work, the involvement oftyrosine kinases and protein kinase C in mediating of the previously revealed modulating effects of prolactin on the nuclear maturation of bovine oocytes and the morphologic-functional state of surrounding cumulus cells was investigated in vitro. Tyrosine kinase inhibitor, genistein, was found to suppress the stimulating action of prolactin on the completion of oocyte nuclear maturation and cumulus expansion, whereas protein kinase C inhibitor, calpostin C, did not affect these hormonal effects. Furthermore, both genistein and calpostin C inhibited the inducing influence of prolactin on the proliferative activity of cumulus cells. At the same time the retarding action ofprolactin on destructive processes in cumulus cells was blocked only in the presence of calpostin C. The results of the study suggest that the stimulatory influence of prolactin on oocyte nuclear maturation and attendant cumulus expansion is achieved with the participation of tyrosine kinases, whereas the modulating action of the hormone on the functional state of cumulus cells depends on activation of not only tyrosine kinases, but also protein kinase C.

[Interaction of signal cascades induced by cAMP and prolactin in bovine oocyte-cumulus complexes].

Prolactin (PRL) is one of the pituitary hormones participating in the control of mammalian folliculo- and oogenesis. In the present study, the joint effect of PRL (50 ng/ml) and dibutyryl cAMP (dbcAMP, 1 mM) on oocyte maturation and the morphologic-functional state of surrounding cumulus cells was investigated in vitro. It has been shown that PRL totally suppresses the braking impact of dbcAMP on meiosis reinitiation and the completion of oocyte nuclear maturation. Furthermore, PRL partly inhibited cumulus expansion induced by dbcAMP, although it exerted the opposite effect in the control medium. In the presence of PRL, the inhibitory impact of dbcAMP on the proliferative activity of cumulus cells and on the PRL-elicited braking of destructive processes in the cells has been found. In cumulus cells, mRNA expression of PRL receptor long isoform was revealed by the RT-PCR method. The data obtained suggest an interaction of signal cascades induced by PRL and cAMP in bovine oocyte-cumulus complexes, with the coupling site of these cascades in oocytes being apparently different from that in cumulus cells.

[Cytogenetic and immunological specificity of mammalian hybrid cell lines].

Karyotypes of the hybrid cell lines NS-RL-3 (TK- -sheep kidney cells and rabbit lymphocytes) and betaCR-NS (TK- -rabbit beta-cells and TK- -sheep kidney cells) were investigated. It was shown that both hybrid cell lines were characterized by presence of both sheep and rabbit chromosomes, which number and structure varies depending on the cell type and the number of passages. In some cases the aberrant chromosomes were identified. It was observed, that 40-50% of the NS-RL-3 cells survived in culture in the presence of the human blood serum, and also were identified during 7-28 days after their introduction into the organism of the animal. Thus, the partial immunological tolerance of the hybrid cell lines has been suggested.

[Retroviral-mediated gene transfer as an effective tool for the in vitro genetic transformation of chicken embryonic cells and production of transgenic chickens].

The data on the in vitro and in vivo (into embryonic disk) retroviral-mediated transfer of genetic information into chicken embryonic cells are presented. The estimated transformation frequency of the cultured target cells constituted 8 x 10(-4) to 5 x 10(-3). A transgenic rooster, carrying recombinant DNA in blood, heart, liver, and intestine cells, was obtained.

[Dynamics of spermatogenesis in rabbits Oryctolagus cuniculus].

The rabbit spermatogenesis was investigated in dynamics with morphology of testicular tissues being analysed. Allocation characteristic of spermatogenous epithelium cells in spermatic ductules was examined for 19 age groups of rabbit males aged from 10 days to 12 months. The availability of three types of spermatogonia A, intermediate and B was analysed. In has been determined that the age from 10 days to 4 weeks is optimal for isolation of testis stem cells, when rabbit spermatogonia are represented by spermatogonia of A-type only.

[Development of the mammary gland of rabbits].

Mammogenesis of rabbits was studied in dynamics, including periods of sexual maturity (3-6 months old), pregnancy, lactation and involution. A characteristic of histological structure of mammary gland of rabbits in different physiological periods was done. Variation in maintenance of glandular tissue of mammary gland during mammogenesis was analyzed. It has been shown that the share of parenchyma tissue is increased with the pregnancy onset and achieves its maximum value by the 25-30 th days of pregnancy. The increase in densities of mammocyte nucleus in this period and also in the period preceding the sexual maturity was observed that is associated with the active proliferation of cells. It is shown that an in vitro cell culture, derived during the period preceding the sexual maturity, has a great grown potential, whereas a culture devired in the course of lactogenesis is characterized by the presence of highly specific lactocytes and has a low proliferative activity.

[Functional status of the intima and thrombocytic hemostasis in patients with symptoms of atherosclerosis of the cerebral and peripheral vessels]. / Funktsional'noe sostoianie intimy i trombotsitarnogo gemostaza u bol'nykh s proiavleniiami ateroskleroza mozgovykh i perifericheskikh sosudov.

The indices characterizing the state of lipid metabolism, endothelium of arteries and thrombocytic hemostasis were investigated. It was shown that in the zone of atherosclerotic stenosis of the arteries there were marked transformations of the endothelium followed by a decrease of their anticoagulatory properties. The cause and effect relationship between the disturbed thrombocytic hemostasis and lesions of the endothelium in atherosclerosis was confirmed. It is these factors which are the cause of frequent thromboembolic complications, especially in patients with lesions of the cerebral arteries. It is necessary to include methods of correction of the disturbed thrombocytic hemostasis in the complex treatment of patients with atherosclerosis.

[Obtaining eggs and the transplantation of microinjected zygotes in rabbits]. / Poluchenie iaitsekletok i peresadka mikroin''etsirovannykh zigot u krolikov.

A system of preparation of donors and recipients, providing for the optimal reaction of donors to superovulation, good survival of zygotes after transplantation, and high degree of fertility of the recipients, is characterized within the framework of gene and embryo transfer programs in rabbits. The technique of laparoscopy a fast and efficient method of nonsurgical transplantation of zygotes in rabbits, is described.