Association of genetic variants of Forebrain Embryonic Zinc Finger-like (FEZL) gene exon 3 with clinical mastitis in Murrah buffaloes (Bubalus bubalis)

Abstract

Forebrain embryonic zinc finger-like (FEZL) gene is an important candidate gene, which affects the host disease resistance. The gene has been mapped on BTA22 and consists of 6 exons and 5 introns spanning over 4685 bp. Present investigation was carried out with an aim to identify genetic polymorphism within exon 3 of FEZL gene and its association with incidence of clinical mastitis in Murrah buffaloes. Genomic DNA extracted from 110 Murrah buffaloes were amplified using two sets of primers and respective PCR products of 554 bp and 474 bp were obtained. A total of 4 nucleotide sequence variations in exon 3 were observed. Two SNPs g.1556C>T and g.1707G>A were non synonymous, which resulted in amino acid substitution of isoleucine to threonine and methionine to valine at protein position 31 and 83, respectively. PCR-RFLP using MspI for primer 3.1 and DraI for primer 3.2 revealed monomorphic patterns, while TaqI for primer 3.1 exhibited polymorphism with CC, CT and TT genotypes with respective frequencies of 0.35, 0.21 and 0.44. Association of identified genotypes with clinical mastitis has been found to be significant (p<0.01).Odds Ratio (OR) analysis confirmed significant association (OR=6.8531; 95% CI) and TT genotype of SNP g.1556C>T of FEZL gene emerged as the most favoured and may be used as a potential marker for selecting Murrah buffaloes less susceptible to mastitis, after validation in a larger herd.