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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. [ABSTRACT FROM AUTHOR]

In the present study, polymorphisms at two single nucleotide polymorphisms (SNPs)  and one microsatellite locus of SLC11A1 gene were investigated for finding their association with susceptibility to bovine tuberculosis trait (tuberculin reaction) in Indian cattle. A total of 245 animals were tested with single intradermal tuberculin test for screening positive animals for tuberculin reaction. At rs109915208 locus very low polymorphism information content of 0.0454 was observed, whereas it was moderate (0.352) at rs109453173 locus of SLC11A1. At rs109915208 locus the genotypic as well as allelic frequencies were differing significantly (p-value < .05) in case–control animals where the odds ratio (OR) of ‘CC’verses‘CT’ genotype and the OR of ‘C’verses ‘T’ allele were approaching towards infinity, suggesting that animals having ‘CT’ genotype and ‘T’ allele were less susceptible for tuberculin reaction as compared to their contemporary genotype/allele. The significantly associated SNP was non-synonymous causing an amino acid change. [ABSTRACT FROM PUBLISHER]

Bovine tuberculosis is an important disease of cattle with zoonotic importance. A resource population comprising of 35 Case and 49 Control animals of indigenous cattle population was genotyped for a SNP from intergenic region of SLC6A6 gene, which have an established association with bovine tuberculosis susceptibility in Holstein-Freisian cattle population. Polymorphism in indigenous resource population at the targeted SNP revealed the presence of this SNP in indigenous cattle also. Both the alleles i.e. G and T and all possible three genotypes i.e. GG, GT and TT were observed in indigenous cattle. Low Polymorphic Information Content but high heterozygocity was observed at this SNP. The probability values showed that the genotype (P=0.38) as well as allele (P=0.53) had no significant effect on occurrence of bovine tuberculosis. [ABSTRACT FROM AUTHOR]

Aim: Toll-like receptor 2 (TLR2) and TLR4 genes play critical roles in host recognition of Mycobacterium bovis infection and initiation of innate and adaptive immune response. The present study was aimed at exploring the association of seven single nucleotide polymorphisms (SNPs) in TLR2 and TLR4 genes with susceptibility/resistance against bovine tuberculosis (bTB) infection in cattle. Materials and Methods: A case-control resource population of 35 positive and 45 negative animals was developed after screening with single intradermal tuberculin test for bTB. Resource population was screened for SNPs in TLR2 and TLR4 genes using polymerase chain reaction-restriction fragment length polymorphism. The PROC LOGISTIC procedure of SAS 9.3 was used to find an association of allelic and genotypic frequencies with bTB. Results: In TLR2 gene, two of SNPs under study (rs55617172 and rs68268253) revealed polymorphism while in the case of TLR4 gene all four SNPs under investigation (rs8193041, rs207836014, rs8193060, and rs8193069) were found to be polymorphic in case-control population. SNP locus rs55617172 in TLR2 gene was found significantly (p<0.01) associated with susceptibility/resistance to TB in cattle. Conclusion: These findings indicate the presence of SNPs in TLR2 and TLR4 genes in our resource population. Upon validation in independent, large resource population and following biological characterization, SNP rs55617172 can be incorporated in marker panel for selection of animals with greater resistance to bTB. [ABSTRACT FROM AUTHOR]