Polymorphism of the BoLA-DRB3 gene in bull sires of the Kostroma breed as genetic factor of the resistance to leukemia
Allelic polymorphism of the second exon of the BoLA-DRB3 gene in groups of bull sires of the Kostroma breed with different relationships by blood related to the Brown Swiss (BS) breed was analyzed. When BS blood relationship was increasing the frequencies of alleles causing resistance to the bovine leukemia virus were decreasing and amounted to: in the group of thoroughbred bulls of the Kostroma breed - 0,300, in the group of bulls with the BS blood relationship equals to 50 % or less - 0,185, in the group of bulls with the BS blood relationship more than 50 % - 0,154. On the whole, 17 alleles were identified in the studied sample indicating moderate level of allelic diversity.