Single nucleotide polymorphism in TLR1 and TNFá genes and their association with susceptibility to bovine tuberculosis

Identification of genetic predispositions to susceptibility towards bovine tuberculosis (bTB) for the purpose of improving herd resistance to bTB through marker/genomic selection has been one of the thrust areas of research in animal production. Immune response genes, such as Toll Like Receptors (TLRs) which are involved in mycobacterial recognition and activation of innate and adaptive immune responses and Tumor Necrosis Factor alpha (TNFa) which is a vital pro-inflammatory cytokine with pleiotropic roles in immune response that enables mounting of a strong microbicidal action, are potential strong candidates for exploring genetic basis of resistance. Present investigation was aimed at exploring the association of three SNPs (rs43702940, rs68343175 and rs55617317) in TLR1 gene and one SNP (rs109967811) in TNFa gene with susceptibility to bTB infection in cattle. In a case-control population of bTB established using single intradermal tuberculin test, three of the investigated SNPs were found to be polymorphic while rs43702940 revealed monomorphism. SNP loci rs109967811 in TNFa gene was found to be significantly (P < 0.01) associated with susceptibility to bTB in the study population. These findings suggest that SNPs rs109967811 located in exonic region of TNFa can likely serve as a potential marker against bTB infection in cattle upon validation in independent, larger resource population.