Polymorphism of the CAST gene in sheep of different breeds of the North Caucasus

Advances in animal genetics and breeding technologies have led to the widespread use of molecular markers to improve and select economically valuable traits in sheep farming. This article presents the material on DNA testing by PCR- RFLP of sheep of different breeds (Stavropol, Manych merino, North Caucasian meat and wool, Dagestan mountain, Russian meat merino, Kalmyk kurdyuchnaya, Kalmyk kurdyuchnaya (crossbreeds with a bloodline of ? Kalmyk kurdyuchnaya + ? Charolais), Dzhalginsky and Chernozemelsky merino), bred in conditions of various farms in the North Caucasus. In all the studied breeds, the frequency of the СASTМ allele significantly exceeded the frequency of the CASTN allele and was in the range from 0.78 to 0.90, therefore, the frequency of the CASTN allele was in the range from 0.22 to 0.10. The homozygous СASTММ genotype prevails in the genetic structure of sheep of different breeds according to the СAST gene. The heterozygous СASTMN genotype in the studied sheep samples ranged from 14.0 to 36.0 %, whereas the frequency of occurrence of the desired homozygous СASTNN genotype in all studied breeds was low and ranged from complete absence (0.0 %) to 7.0 %.