Abstract:Myostatin (MSTN) is a negative regulator of muscle growth that inhibits myoblast proliferation and differentiation.In order to explore the possibility of MSTN gene as a candidate for growth traits in Lanzhou fat-tailed sheep,PCR amplification and PCR-SSCP technology were used to detect the polymorphisms of MSTN gene in 536 Lanzhou fat-tailed sheep,and their population distribution was analyzed.Results:(1)Two SNPs were detected in the MSTN gene of Lanzhou fat-tailed sheep,among which the alleles of g.119286026C>A were CC and CA,and the CC genotype’s chest width and circumference were prominently higher than CA genotype (P<0.05),the alleles of g.119286166A>G locus were AA and AG,and the AG genotype’s body oblique length and weight of the were prominently higher than AA genotype (P<0.05),both points showed low polymorphism.(2)Genotypic combination analysis showed that two genotype combinations (A1 and C1) had a significant effect on the growth traits of Lanzhou fattailed sheep,and the body oblique length and chest circumference,width and depth of the genotype group C1 were prominently higher than genotype group B1 (P<0.05),and there were noprominent differences in other growth traits between genotype groups (P>0.05).The results showed that MSTN gene polymorphisms were prominently related with body oblique length,body weight,chest circumference and width of Lanzhou fat-tailed sheep,which could be used as an effective genetic marker site for their growth traits.