Molecular analysis of TLR4 gene and its association with intra-mammary infections in Sahiwal cattle and Murrah buffaloes

267-273Toll-like receptors (TLRs) are a multigene family of pathogen recognition and play a central role in the initiation of inflammation response and subsequent adaptive immune system. In the present study, genotypes of TLR4 variants were analysed in mastitic cattle and buffaloes. Genome of selected animals (n=218) comprising of Sahiwal (n=110) cattle and Murrah (n=108) buffaloes on the basis of their health history as well as on the causative agents screening, were analysed for polymorphisms in TLR4 using PCR-RFLP. Molecular analysis of TLR4 gene revealed two alleles (A and B) and three genotypes (<i style="mso-bidi-font-style: normal">AA, BB & AB) in both the breeds. Incidence of mastitis showed significant association of TLR4 variants with non-staphylococci microbes. Genotype BB (Sahiwal, 0.613; Murrah, 0.703) was found significantly associated with the mastitis irrespective of microbial or other factors, whereas AB predominated (Sahiwal, 0.714; Murrah, 0.772) in unaffected cases. Statistically, association between polymorphism of TLR4 variant and mastitis in both the populations emphasized that genotype<i style="mso-bidi-font-style: normal"> AA were significantly lower than <i style="mso-bidi-font-style: normal">BB (P AA genotype remained prevalent only in case of mixed microbial infection in Murrah, and streptococcal and mixed microbial infection in case of Sahiwal. Allele A might be favourable for mastitis resistance. Chi square test revealed that the two loci of both the populations were in Hardy-Weinberg equilibrium. The observations of present may be helpful in identifying markers of natural resistance against mastitis that could contribute in its containment programme in cattle and buffaloes