Polymorphisms in TLR4 gene associated with risks of bovine mastitis development

Introduction . Inflammatory mammary diseases in cows remain the most common challenge in dairy industry, notwithstanding the improved preventive measures and treatment schemes. One of the methods to prevent mastitis in dairy cows is the genetic selection of the most disease-resistant individuals. Toll-like receptor 4 ( TLR4 ) plays a central role in the innate immune response. There are publications about TLR4 significance for mastitis development, its genetic polymorphisms associated with somatic cell counts. Objective . Determination of genetic diversity and association with the development of clinical mastitis for three polymorphic locuses of TLR4 . Materials and methods . To achieve the objective cattle health history ( n = 421) was used, subclinical mastitis was diagnosed using rapid test for somatic cell counting in milk, TaqMan real-time polymerase chain reaction was used for genotyping of cattle for rs8193046, rs8193060, rs29017188 polymorphisms. Results. Association studies established that rs8193046 и rs29017188 polymorphisms are the most promising candidates to be used in selection programs aimed at mastitis risk mitigation in the Ural populations. For rs8193060 no reliable results of association tests are obtained, though risk of mastitis in GCG haplotype-animals (for SNP rs8193046, rs8193060, rs29017188 alleles) is statistically lower. Conclusion . It is noted that the abovementioned polymorphisms can be used for marker-assisted selection of cattle to prevent risks of mastitis in the populations in the Ural.