Abstract: The single nucleotide polymorphisms （SNPs） of CAPN1 gene in Gannan yak， Tianzhu yak and Datong yak were detected by the technology of PCRSSCP. The relationship between SNPs and Gannan yak carcass and meat quality traits was analyzed. The results of PCRSSCP indicated that there was a genetic mutation of g.100+606G>T in the first introns of CAPN1 gene of all 3 groups to form 3 genotypes （AA， AB and BB）. Genetic analyses of CAPN1 gene showed that the polymorphism information contents in the detection region were 025<PIC<050， which belonged to a moderate polymorphism. Meat tenderness degree， water loss rate， eye muscle area of different age periods of Gannan yaks were regulated by genetic mutation of CAPN1. Lower shear force was observed in AA type yaks aged 3 and 5 years when compared with BB and AB type yaks （P<005）. Higher eye muscle area was observed AA type yaks aged 4 and 5 years old when compared with BB and AB type yaks （P<005）. Moreover， higher water loss rate was observed in 6 years old AA type yaks when compared with BB and AB type yaks （P<005）. Genetic mutation of g.100+606G>T could be used as genetic markers.

Key words: Gannan yak, CAPN1 gene, polymorphism, carcass and meat quality traits