Аннотация
The search and identification of genes responsible for economically useful traits of cattle is relevant. Dairy productivity as a complex quantitative trait, is controlled by a large number of genes and their transcription factors taking into account the physiology of the animal. The dynamics of dairy productivity depends on a number of factors, since the secretory activity of the mammary gland is controlled by a complex of hormones, genes, transcription factors and enzymes. The studied gene Pit-1 (POU1F1) is an informative marker in determining milk and meat productivity. The genotype of an individual determines its productivity potential and the norm of reaction to environmental conditions. Genotypes of the studied gene are identified by polymerase chain reaction and restriction fragment length polymorphism (PCR-PDRP) analysis. When analyzing the data, the chi-square test is used to determine the genotype, allele frequencies and Hardy-Weinberg equilibrium. The object of research – DNA of blood of red steppe, simmental breeds of cattle of Pavlodar region of Kazakhstan. According to the results of amplification of Pit-1 gene fragment the PCR product with the size of 451 bp was obtained. According to the results of amplicon splitting the genotypes AA (451 bp), AB (451, 207, 244 bp) and BB (207, 244 bp) were obtained. In the considered farms of the region genotypes BB, AB prevail. In the studied groups of animals of the region high frequency of allele B is observed; in red steppe – 0.689, simmentals – 0.549; frequency of allele A – 0.312; 0.451 respectively. Genetic equilibrium is not disturbed; the criteria of reliability of the empirical distribution to the theoretical one in red steppe breed – 0.04, in simmentals – 0.16. The revealed associations of Pit-1 gene polymorphism can be used for selection and selecting parental pairs at directed breeding.