Study on Two single nucleotide polymorphisms (SNPs) in Calpastatin Gene and Their Association with Weight Traits among Iranian Indigenous Sheep Breeds

This study examines two single nucleotide polymorphisms (SNPs) in the CAST gene, which plays a crucial role in muscle growth and meat tenderness, in 721 sheep from 16 Iranian indigenous breeds. The goal was to analyze the allelic and genotypic frequencies of these mutations using the PCR-RFLP method. A 620 bp fragment of the CAST gene was amplified by PCR and digested with MspI and NcoI enzymes to target the mutation regions. Both mutations were detected in all breeds. At the MspI locus, the highest frequency of the N allele was observed in the Lori breed (0.243), while the lowest was in the Zel breed (0.048). At the NcoI locus, the highest frequency of the N allele was in the Zandi breed (0.192), and the lowest in the Zel breed (0.024). Pearson correlation coefficient test revealed a positive correlation between the MN genotype at the MspI locus and weight traits such as birth weight, mature weight, and weight gain. A weak positive correlation was also observed between the NN genotype and mature weight and weight gain in both rams and ewes. These findings suggest that the MspI mutation has a stronger influence on weight traits than the NcoI mutation, highlighting its potential as a valuable genetic marker for improving meat production in Iranian sheep breeding programs.