Genetic polymorphism of melatonin receptor 1A (MTNR1A) gene in Indian sheep breeds

Polymorphism in the melatonin receptor 1A (MTNR1A) is associated with seasonal reproduction of sheep. Genetic polymorphism in MTNR1A gene was investigated in 4 Indian sheep breeds reared in semi-arid and arid region of the Rajasthan. In this study, blood samples were collected from 171 animals. DNA was extracted from white blood cells. The PCR product (824bp) of exon II fragment of sheep MTNR1A gene was amplified. PCR products were digested separately with 2 restriction endonucleases, viz. MnII and RsaI. Polymorphism was detected at both loci of MTNR1A gene. At MnII locus, allele frequency for Magra, Garole, Malpura and Avikalin breed was found as 0.74, 0.74, 0.78, and 0.84 for M allele and 0.26, 0.26, 0.22, 0.16 for N allele, respectively. At RsaI locus, allele frequency was found as 0.90, 0.83, 0.69, and 0.59, for R allele and 0.10, 0.17, 0.31, 0.41 for r allele, respectively. It was concluded that the frequencies of ‘M’ and ‘R’ alleles of MTNR1A were higher in Indian sheep breeds.