The myostatin gene(MSTN) and its relationship with muscle fiber traits in chickens
To investigate the influence of the MSTN gene on muscle fiber traits of quality chickens, polymorphisms of the myostatin(MSTN) gene from S3 line quality chickens was detected by PCR-SSCP and sequencing technology. Two SNPs were identified at G195 C and A234 G of the MSTN gene. Both SNPs were in Hardy-Weinberg balance(P0.05) in all the chicken populations except for the G195 C locus in the cock population. The effects of these polymorphisms of the MSTN gene on fiber traits were analyzed. The result showed that there were significant differences in breast muscle weight, thigh muscle weight and muscle fiber density between the genotype CC and GG hens of S3 line at G195C(P0.05). The genotype CC was significantly higher in muscle fiber area than that of GG genotype(P0.01).The muscle fiber density of GG genotype was less than the AA genotype(P0.05), and muscle fiber area was significantly higher than AA genotype at A234G(P 0.01).The haplotype effects of CCGG on carcass weight, breast muscle weight, thigh muscle weight, muscle fiber density and muscle fiber area were greater than that of haplotype genotype GGAA(P0.05). There was no difference between genotype CC and GGAA on carcass weight, breast muscle weight and thigh muscle weight at G195 C and A234 G of cocks(P0.05). The muscle fiber density of GG genotype was less than the AA genotype(P 0.05), and muscle fiber area was significantly higher than the AA genotype at A234G(P0.01). The haplotype effects of CCGG on carcass weight, breast muscle weight, thigh muscle weight were greater than that of haplotype genotype GGAA(P0.05), and haplotype genotypes of CCGG and GGAA showed significant difference between muscle fiber area and density of muscle fiber(P 0.01).These results preliminarily showed that MSTN was a major gene that influences the skeletal muscle growth of chicken and provided genetic information on muscle growth in quality chickens. The genetic basis of muscle growth affected by MSTN in chickens should be further studied.