Genetic polymorphism at MTNR1A, CAST and CAPN loci in Iranian Karakul sheep

Genotypes for melatonin receptor type 1A (MTNR1A) and Calpastatin (CAST) were determined by enzymatic digestion of PCR products and Calpain(CAPN) genotype detected by PCR-SSCP method in Iranian Karakul sheep. Blood samples were collected from 100 purebred Karakul sheep. The extraction of genomic DNA was based on guanidinium thiocyanate-silica gel method. PCR amplicons were digested with restriction enzymes MnlI and MspI for MTNR1A and CAST genes, respectively. The MTNR1A locus had two alleles with frequencies of 0.79 for (+) and 0.21 for (-) alleles. Allelic frequencies for CAST locus were 0.85 for M and 0.15 for N. In addition, Calpain had two alleles A and B with respective frequencies of 0.79 and 0.21. The observed heterozygosity values for MTNR1A, Calpastatin and Calpain locus were 0.42, 0.29 and 0.35, respectively. The X2 test confirmed the existence of Hardy-Weinberg equilibrium for the three loci in the population. The data showed a large variation in studied genes. The genetic polymorphism could be regarded as useful tool for selection programs based on marker- assisted selection between different genotypes of those loci.