Polymorphism of calpastatin, calpain and myostatin genes in native Dalagh sheep in Iran

Abstract

Calpains play a major role in post mortem tenderization and calpastatin is the endogenous inhibitor of calpain proteases and regulates the rate and extent of post mortem tenderization. Myostatin is an inhibitor of skeletal muscle growth and a mutation in the gene coding region leads to increased muscling. Therefore, they are considered as candidate genes for meat and growth traits. Blood samples were collected from 110 Dalagh sheep and DNA were extracted using modified salting out extraction method. Genotypes were determined by PCR amplification followed by single-strand conformation polymorphism (SSCP) method for calpain gene and restriction fragment length polymorphism (RFLP) method for calpastatin and myostatin genes. Based on results, calpastatin and calpain genes were found to be polymorphic but myostatin gene was monomorphic. Genotype frequencies were 36, 38, and 26 % for MM, MN and NN in calpastatin locus, respectively. In this population, calpastatin locus did not show Hardy-Weinberg equilibrium (P<0.05). Observed heterozygosity for this locus was good (0.38). Under the SSCP analysis, three different patterns (G1 , G2 and G3 ) with frequencies of 8.2, 89.1, and 2.7 % were detected in calpain locus, respectively. Detected polymorphisms and assumed associations of genetic variation with meat production and tenderness may help to find the effective genotypes of Dalagh sheep for those economic traits.