The article presents the results of studying Calpastatin (CAST) gene polymorphism in Tsigai (n = 23) and Merinoland sheep breed 13). purpose research. possibility using PCR-RFLP analysis to detect was primary objective this ongoing study. Research methods. analyzed by MspI endonuclease restriction. Results. We revealed diversity genotypes allelic variants Breeds. It found that M allele locus is...