STUDY OF THE GENETIC STRUCTURE OF THE POPULATION OF THE UKRAINIAN INDIGENOUS LEBEDYN BREED OF COWS

Abstract

The article presents the results of the study of structural genes in the population of the Ukrainian indigenous Lebedyn breed of cows, which are associated with milk productivity: CSN2 (betacasein), CSN3 (kappa-casein), BLG (beta-lactoglobulin). These genes encode milk proteins and are important genetic factors that influence the quality and composition of cows’ milk. Studying the genetic structure of aboriginal breeds of cattle is important for understanding the evolution and distribution of the animal gene pool. This can be useful for the conservation of these breeds, as well as for improving their performance and adaptation to environmental changes. A total of 3 gene polymorphisms (CSN2, CSN3, BLG) were investigated. For the research, 32 samples of DNA isolated from the venous blood of Swan breed cows using the "DNA Sorb-B" kit (AmpliSens) were used. Genotyping was performed using polymerase chain reaction (PCR-PCR) polymorphism analysis of restriction fragment lengths. The amplified fragment of CSN2 (121 bp) was treated with DdeI restriction enzyme. A feature of the allelic spectrum of the beta-casein gene in the studied animals is the significant predominance of the A1 allele (0.75). No animals with the A2A2 genotype were found. For the CSN3 gene, an amplified fragment with a size of 273 bp. treated with HinfI restriction enzyme. The absence of animals with the CSN3BB genotype and a high frequency of the A allele (0.81) were established. When studying the BLG gene, the amplification product (247 bp) was treated with the restriction enzyme HaeIII. It was found that allele B (0.77) and genotype BLGVV (0.7) were more common. Features of the allelic spectrum of CSN2 (А2-0.25), CSN3 (А-0.81), BLG (В-0.77) genes, which are characteristic of the studied population of the Ukrainian indigenous Lebedyn breed of cows, were revealed. The results of the study are valuable in connection with the sharp reduction in the number of local indigenous populations and the threat of extinction of the own genetic resources of agricultural species.