BoLA-DRB3 gene as a marker of sensitivity of the white-headed Ukrainian cattle to mastitis

Abstract

Mastitis in cows is an important problem in the milk industry. Major histocompatibility complex (MHC), also called bovine lymphocyte antigen (BoLA), is attracting attention due to its association with host immunity. The BoLA system has some equally operating genes that provide antigen presentation by MHC system molecules followed by an immune response to pathogens. Exon 2 of the BoLA-DRB3 gene is the most important and highly polymorphic. Alleles that had a close connection with mastitis have been detected and are considered DNA markers. These play a decisive role in the breeding of cattle to create herds resistant to diseases. Polymorphism of the BoLA-DRB3 gene (exon 2) of the White-Headed Ukrainian cattle breed was studied by PCR-RFLP to search for DNA markers associated with mastitis. In the general sample and group of resistance cows, 28 alleles were found, and in the group of animals prone to mastitis – 21 BoLA-DRB3.2 alleles. The most common variant was BoLA-DRB3.2*24 (12.3%). It also dominated among cows susceptible to mastitis (25.9%). Allele *22 (13%) maximally showed the animal’s resistance to the disease. Based on relative risk, it has been reliably established that there are at least two mastitis-sensitive alleles: variant BoLA-DRB3.2*22 (p<0.05) associated with resistance, and *24 – with a susceptibility to the disease (p<0.001). It was also established that the genotype DRB3.2*11/*24 (p<0.01) can be used as a DNA marker of mastitis resistance after additional verification. The obtained results will be useful in the formation of herds of dairy cows resistant to mastitis.

Keywords

• dna
• allele
• selection
• cow
• disease resistance