A repetitive DNA sequence, MS2, was isolated from EcoRI-digested genomic DNA of the vole, Microtus subarvalis. The fragment was cloned and sequenced. Sequence analysis of this 1194-bp fragment revealed a 156-bp region demonstrating a 55% homology with the mouse B1 repeat. The remaining MS2 sequence shows no significant homology with other known GenBank sequences. The results of in situ hybridization of MS2 on vole metaphase chromosomes indicate the fragment is confined to heterochromatin blocks of the sex chromosomes in all but one species (M. arvalis). Distribution of MS2 sequences provides evidence for heterogeneity of the giant heterochromatin blocks of the XY Chromosomes (Chrs) in voles, for the unique cluster-like localization of MS2 within these blocks.

Integration sites for HTLV-1 and HIV-1proviruses were detected by FISH on the chromosomes of HTHIV27 cells persistently infected by HIV-1 (strain IIIB). HTLV-1 signals were found on 9 loci of chromosomes 4, 6, 9, 15 and 16. Integration sites of GC-rich HTLV-1 provirus are located in GC-rich isochores, confirming an 'isopycnic' integration, namely an integration in which the GC level of the host sequences around the integration site match the GC level of the provirus. This conclusion is not only derived from the compositional map of human chromosomes, but also from HTLV-1 hybridization on compositional fractions of human DNA. Integration of GC-poor HIV-1 provirus was found on 4 loci of chromosomes 2, 7, 17 and 19. One copy of a complete HIV-1 provirus, which is active, was integrated in H1 isochores, whereas other defective copies were located in GC-poor L isochores. These results are discussed in terms of regional integration of retroviral sequences.

The article analyzes the state and development of small business in the federal districts of the Russian Federation: dynamics and structure of the number of enterprises, the average number of employees, product turnover. The role of small enterprises in the Russian economy has been established. The data on the sectoral structure of this form of entrepreneurship and the distribution of small enterprises according to the assessment of investment in fixed assets are given. The problems that hinder the development of small business have been identified.

The North Caucasian Federal District lags behind other administrative-territorial units of the country in the development of small businesses (low population density, the smallest territory, lack of access to the world ocean), as evidenced by the studied indicators, but it has regions with attractive market segments based on resources and specifics of local markets. In particular, in the Stavropol Territory, the top three industries include the manufacturing industry with a high share of trade turnover (2018% in 48,1). In this regard, this paper proposes three scenarios for the development of small business in the manufacturing industry: inertial, moderately optimistic and accelerated.

The maximum value of the indicator of the photosynthetic potential was fixed at sowing in the third decade of April, 12-13 flowering leaves in the interphase period-1189-1686 thousand m 2 /ha. The ripeness group of the hybrid influenced the formation of the photosynthetic potential. The highest values of the indicator were established during all the sowing periods of the midseason of the Kahovski Hoghbroide, which were in the period of 12-13 leaves-flowering of the rockers in the range of 1375-1686 thousand m 2 /ha.