Polymorphism and Haplotype Structure of TLR2 Gene Associated with Endometritis Infection in Water Buffalo

Water buffalo plays an essential role in the economy of Egypt and most of developing countries where it considers the main source of meat and milk, therefore studying the reduction of buffalo reproductive performance is a very important issue. Toll-like receptors (TLRs) are important for the recognition of pathogen-associated molecular patterns and activating proper immune responses.Single nucleotide polymorphisms (SNPs) within TLRs have a potential impact on the alteration of susceptibility or resistance to infectious and inflammatory diseases. This work focused on a case-control study for the distribution of SNPs in TLR2 gene to test their role as risk factors for endometritis occurrence in water buffalo.The case-control study included 40 uterine tissues, where 20 tissues showed endometritis while the remaining were normal controls.Nineteen novel polymorphic sites were identified, where two SNPs were located at 5`UTR, fifteen at the coding region and two SNPs at 3` UTR. Three SNPs were found to be statistically significant between cases and controls, one of these SNPs was located at the coding region while the other two were located at 5` UTR. AA genotype at 5` UTR and CC genotype at the coding region had significant association with susceptibility to endometritis, while GG genotype at 5`UTR had significant association with resistance to endometritis. Polyphen 2 analysis revealed three amino acids substitutions in TLR2 protein having potential functional significance. Haplotype reconstruction in coding region of TLR2 was performed by PHASE v2.1.The statistical significance of haplotype frequencies between cases and controls indicated its association with the occurrence of endometritis.