INVESTIGATION OF GENE GH<sub>O</sub> POLYMORPHISM in TUva short-fat tailed sheeps
Genotyping data of Tuva short-fat tailed sheeps on the growth hormone gene ( GHo ) are presented. Tuva short-fat tailed sheep is a unique local breed that is widespread in the territory of the modern Tuva Region and in some adjacent regions, including mountain and steppe inter-breed types, characterized by excellent meat qualities. Currently, the sheep industry in this region is of an extensive nature and, for possible intensification and improvement of economic efficiency, the possibility of using DNA marking at some stages of breeding and breeding work is being considered. The growth hormone ( GHo ) gene is currently being considered as a marker of the economic benefits of sheep in terms of growth, overall development and live weight. In the course of the research, information was obtained on the presence of A and B allelic variants of the GHo gene from the sheep-producers of the mountain intra-breed type of the Tuvan short-fat-tailed breed of the agricultural organization of the GUP RT “Malchyn” of Mongun-Taiginsky district of the Republic of Tuva. All possible genotypes were found: AA, AB and BB. The frequency of occurrence of the identified genotypes in the representatives of the breed studied was AA - 0.490, AB - 0.370 and BB - 0.140, respectively. In the breed there is a predominance of the GHo<sup>A</sup> allele (frequency of occurrence is 0.675). According to the results obtained, 86% of the sheep-producers are carriers of the A allele of the growth hormone gene in its genotype. Identified VV genotype is the rarest in the occurrence in the studied group of animals, however, 51% of the sheep-producers are carriers of B allele in their genotype. The incidence of allele GHo<sup>B</sup> was 0.325. Thus, the nature of the manifestation of polymorphic variants of the growth hormone gene in sheep-producers of the mountain in-breed type of Tuvan short-fat tailed sheeps suggests the potential convenience of further use of this marker gene for organizing studies aimed at revealing the relationship between the level of sheep productivity with certain genotypes.