Vol 31, No 4 (2016)

This paper reviews how mammalian genomes are utilized in modern genetics for the detection of genes and polymorphisms (mutations) within domesticated animal (mostly livestock) genomes that are related to traits of economic importance to humans. Examples are given of how genetic analysis allows to determine key genes associated with the quality and quantity of milk in cattle and key genes for meat production. Various questions are reviewed, such as how contemporary methods of genome sequencing allow to maximise the effective detection of coding and regulatory DNA polymorphisms within the genomes of major domesticated mammals (cattle, sheep and pigs) and the history of their formation from the standpoint of genetics.

Recombinant bone morphogenetic protein-2 (rhBMP-2) has pronounced osteoinductive properties, as evidenced by the results of experimental and clinical practices. This applies to both the protein produced in eukaryotic cells and the protein synthesized in bacterial cells. In eukaryotic expression systems, production of the protein is extremely low and, consequently, the cost of materials on its basis is very high. Therefore, optimization of heterologous expression systems for rhBMP-2 production represents an important task. In the present work, optimization of codon composition of the rhBMP-2 gene nucleotide sequence and secondary structure of the transcript, as well as strain selection for efficient gene expression, were carried out. The producing strain based on Escherichia coli BL-21(DE3) provides a high level of rhBMP-2 synthesis (about 57% of total cell proteins). Biological activity of rhBMP-2 dimeric forms purified from the obtained producing strain was measured by induction of alkaline phosphatase activity in C2C12 cells. It is comparable with that of commercial rhBMP-2 expressed in E. coli (R&D Systems, United States). Purified rhBMP-2 does not contain impurities of E. coli endotoxin and can be used in experimental studies of osteoinduction in laboratory animals.

In this article, the role of group B streptococcus in the development of nosocomial infection in maternity hospitals is discussed. Its features, prevalence, and infection risk factors, as well as various forms of bacterial infection in infants, pregnant women, and women in childbirth are considered. World data and the data from own research on the role of group B streptococcus in obstetrics and perinatology are presented.

Vaccinia virus (VACV) possesses a natural oncolytic activity, for the enhancement of which genes encoding various effector molecules, for example, those inducing apoptotic death of tumor cells, are introduced into the virus genome. One such transgene is the gene encoding apoptin protein. The aim of the current work was to study antitumor activity of the apoptin-producing recombinant VACV strain VVdGF-ApoS24/2 in a syngenic murine tumor model. An Ehrlich carcinoma was implanted subcutaneously or intraperitoneally into C57B1 line mice. After tumor development, mice were intratumorally injected with 10⁷ PFU/mouse of VVdGF-ApoS24/2 virus in a single dose, while control mice received 0.9% NaCl solution. Animals were sacrificed at different times after VACV injection. Tumor samples and ascetic fluid cells were fixed in 4% paraformaldehyde and further studied by light microscopy, immunohistochemistry, and electron microscopy. Virus titers in tumor cells were determined by the PFU method. VVdGF-ApoS24/2 VACV strain caused a significant reduction in the volumes of both solid and ascites Ehrlich carcinomas compared to the tumors in the control group of mice, although the virus reproduction rate in the tumor cells was rather low. The antitumor effect of VVdGF-ApoS24/2 could neither be attributed to virus-induced destruction, necrosis, or apoptosis of tumor cells nor to accumulation of the immune-effector cells in the tumors. A decrease in the number of tumor cells undergoing mitosis was observed when examining carcinoma sections, while counting Ki-67 and PCNA positive cells and analysis of their numbers showed that VVdGF-ApoS24/2 strain arrests cell cycle in the S-phase, thereby blocking tumor-cell division and slowing down tumor growth. The obtained results indicate that the insertion of the gene encoding apoptin into the genome of the original L-IVP VACV strain improved the ability of the virus to arrest the cell cycle in Ehrlich carcinoma cells.