S. Khederzadeh - Department of Genetics and Biotechnology, Faculty of Biological Sciences,Varamin-Pishva Branch, Islamic Azad University, Varamin, PO Box ۳۳۸۱۷-۷۴۸۹۵, Iran.
M. Iranmanesh - Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, PO Box ۷۶۱۶۹-۱۳۳, Iran.
R. Motamedi-Mojdehi - Department of Biology, Faculty of Sciences, Razi University, Kermanshah, Iran.

Myostatin (MSTN) is an inhibitor of skeletal muscle growth, and a mutation in the gene coding region leads to increased muscling. Calpastatin (CAST) is a specific inhibitor of the ubiquitous calcium-dependent proteases, µ-calpain and m-calpain, found in mammalian tissues. In this study, genomic DNA was extracted from Zandi sheep blood samples. Gel monitoring and spectrophotometer methods were used to determine the quality and quantity of DNA. Exon 3 of myostatin gene and intron 1 from L domain of the ovine calpastatin gene were amplified to produce 337 and 622 bp fragments, respectively. The PCR products obtained for the myostatin (MSTN) and calpastatin (CAST) genes were digested by the restriction endonuclease enzymes HhaIII and MspI,  respectively. The digested products were separated by electrophoresis on 1.5% agarose gel and visualized after staining with GelRed on UV transillumination. The HhaIII digestion of the PCR products produced digestion fragments of 81, 123 and 131 bp. The MspI digestion produced fragments of 286 and 336 bp. Data analysis was conducted using PopGen32 software. In this population, mm genotype and AA, AB and BB genotypes were identified with 100% and 60, 36, 4% frequencies for MSTN and CAST genes, respectively. This sheep population was in Hardy-Weinberg equilibrium for the CAST gene. The polymorphism found in the CAST gene may be helpful in selection programs for genetic improvement of meat traits. However, before application in the genetic improvement of the indigenous sheep breeds, the association of these polymorphisms with meat traits needs to be established in these breeds.

Myostatin, calpastatin, polymorphism, Zandi sheep