GENETIC STRUCTURE OF HORSES POPULATION FOR THE GENES OF SCID AND HYPP

Objective: identification of carrier animals of the hereditary anomaly SCID and HYPP of the population of horses bred on breeding horse farms of the Republic of Belarus. Methods: genetic, biological. DNA diagnosis of genotypes in the gene severe combined immunodeficiency (SCID) and hyperkaliemic periodic paralysis (HYPP) was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) in the research laboratory «DNA Technology» of educational establishment «Grodno State Agrarian University». We tested 50 horses of different breeds, kept on different breeding horse farms of Belarus. DNA was isolated from buccal epithelium by perchlorate method with double purification (according to the method of Zinovieva). A study of the genetic structure of the horse population for hereditary anomalies of severe combined immunodeficiency and hyperkalemic periodic paralysis was performed using modern equipment. Amplification was carried out using the C1000 Touch thermal cycler (BioRad, USA). The visualization of the gel was carried out using the gel-documenting system Gel Doc XR + (Bio- Rad, USA). Main results. The use of modern methods for the genetic diagnosis of hereditary diseases of agricultural animals not only at birth to exclude from the process of reproduction of animal carriers of hereditary anomalies, but also reduces funding for their maintenance and cultivation. In the studies we used the PCR method based on the use of specific oligonucleotides with which the amplification of the necessary fragment of the 163 gene occurs in healthy individuals and 158 in the mutation carriers, which makes it possible to identify the hereditary SCID disease. We tested 50 animals of the upper and Arabian breeds, as well as horses with an admixture of Arabian blood, among which no carriers of the hereditary anomaly were found. In studies, the PCR-RFLP analysis method was used, based on the use of distinctive primers due to which the necessary fragment of the gene is amplified, which makes it possible to identify the hereditary HYPP disease. Amplified fragments were subjected to the action of restriction enzymes, with the help of which it is possible to determine the genotype of the animal under study. We tested 50 animals of the upper and Arabian breeds, as well as horses with an admixture of Arabian blood, among which no carriers of the hereditary anomaly were found. Conclusions. Severe combined immunodeficiency (SCID) is an autosomal recessive disease that occurs in humans, mice, horses and dogs. Carriers of this hereditary disease are born without visible anomalies, but after 2 weeks they become ill from any infection and die, since they can not develop an antigen-specific immune response. Hyperkaliemic periodic paralysis (HYPP) is an autosomal dominant disease that occurs in horses at the age of 2, when the animal begins, is strengthened to exercise. Symptoms of this disease are weakness of the muscles, periodic spasms, paralysis, which can lead to death. Presumably, there were no carriers of severe combined immunodeficiency in the Republic of Belarus, since breeding farms for breeding horses did not use biological material of Arabian and local breeds of horses for insemination. With subsequent importation of Arabian horses, as well as breeds that have an admixture of Arab blood, it is necessary to conduct DNA testing for the presence of severe combined immunodeficiency (SCID). According to the results of the conducted studies to identify the hereditary disease of hyperkalemic periodic paralysis (HYPP) in the horse population, no carriers were found, as well as sick animals. Presumably, there were no carriers of this disease on the territory of the republic, as evidenced by parallel studies conducted in other European countries, where no carrier or sick animal was found. This suggests that the disease was localized during the time, and also did not leave the territory of the American continent.