Genetic polymorphism of melatonin receptor 1A (MTNR1A) gene in Corriedale sheep of Kashmir, India

The aim of the present work was to explore and characterize the different polymorphic variants of exon II region of MTNR1A gene in 31Corriedale sheep of Kashmir. Genomic DNA was extracted and subjected to PCR for the amplification of the main part of exon II of the ovine MTNR1A gene. PCR products were subjected to restriction enzyme (RE) digestion by MnlI restriction enzyme and depending upon number of sites in the fragment genotypes were classed as MM, Mm and mm genotypes for MnlI RE. Representative samples of all identified alleles were sequenced from forward as well as reverse side. Allelic frequencies were 0.62 and0.38 for allele M and m respectively. The population was observed to be in Hardy-Weinberg equilibrium with regard to allele M and m. Results indicated the existence of polymorphism in the exon II of MTNR1A locus in the breed under study. The various mutational positions recorded in the MTNR1A locus were G169T, G328A, G422A, and C607T. The mutation G422A resulted in amino acid change from Valine to Isoleucine while all other mutations were silent.