Association between SNPS in TLR2 gene segment corresponding to LRR functional domain of TLR2 receptor and bovine mastitis

Abstract

The objective of this study was to understand the association between SNPs reported in the TLR2 gene of cattle and bovine mastitis. Allele Specific-PCR (AS-PCR) was developed for the detection of 6 SNPs (rs55617172, rs111026127, rs68268256, rs68268260, rs68343170 and rs68268268) which were reported to be responsible for change in amino acid present on the LRR-functional domain of TLR2 gene. Fifty well characterized mastitis cases in terms of California Mastitis Test, bacterial culture and PCR and fifty age-matched controls confirmed to be free from mastitis were selected from Puducherry region, India. The DNA was isolated from blood samples of the above animals. AS-PCR was performed with the custom designed primers and genotypes determined. The genotypes detected were further confirmed by sequencing and sequence analysis which had proved the efficiency of AS-PCR developed for the detection of SNPs in TLR2 gene. Statistical analysis of association between genotypes detected with the cases and control resulted in the identification of association (p = 0.0328) between TT genotype for SNP T→G at 385 mRNA position with the control and heterozygous genotype, CT for SNP C→T at 2010 mRNA position (p = 0.0006) with the mastitis. Odds Ratio (OR) analysis with 95% Confidence Intervals (CI) further confirmed significant (OR = 5.76, 95% CI = 2.07-15.97) association between the CT (C→T at 2010 mRNA position) heterozygous genotype and mastitis.