Polymorphism in exon 3 of myostatin (MSTN) gene and its association with growth traits in Indian sheep breeds

The polymorphism of myostatin (MSTN) gene was analysed as a genetic marker for growth traits in Madras Red and Mecheri sheep breeds of Tamil Nadu. PCR-RFLP revealed a SNP G5622C in exon 3 and was confirmed by sequencing. The breed-wise genotypic and allelic frequencies observed for MM genotype were 0.417 and 0.486; and Mm were 0.583 and 0.514 in Madras Red and Mecheri breeds respectively. The estimated allelic frequencies for M and m in Madras Red and Mecheri breeds were 0.7085 and 0.2915; and 0.7430 and 0.2570 respectively. Madras Red sheep with homozygous (MM) genotypes were significantly (P < 0.05) heavier than heterozygous (Mm) genotype by 1.162 kg and 1.227 kg at nine and 12 months weight respectively. However, no significant effect was observed for birth, weaning (three months) and six months weight in the same breed. There was no significant difference in mean birth, weaning, six, nine and 12 months weight between MM and Mm genotypes in Mecheri sheep.