[Single nucleotide polymorphism analysis of the chicken Myostatin gene in different chicken lines]

Myostatin is a new member of the TGF-beta superfamily. It is specifically expressed in skeletal muscle cells and functions as a negative regulator of skeletal muscle growth. This study was aimed to identify the single nucleotide polymorphisms (SNPs) of Myostatin gene in various breeds including Beijing Youji, Baierji, Shiqiza, Dwarf Yellow Chickens, Mini Yellow Chickens, Huiyang Huxuji, Recessive White Chickens, AA and Hyline Layer. The 17 pairs of primers for Myostatin gene were designed based on the chicken genomic sequence. The total 5 SNPs were identified in the chicken Myostatin gene by PCR-SSCP of which 3 were in the 5'-regulatory region and 2 were in the 3'-regulatory region of the Myostatin gene in different chicken lines. The sequence data showed that one of the three SNPs localized in the 5'-regulatory region was due to 3 single point mutations (G304A, A322G, C334T, respectively), other two were single point mutation of G167A and T177C, respectively. The other two SNPs in the 3'-regulatory region of the Myostatin gene are A to T (7263) and A to G (6935). Population genetic analysis indicated that genotype frequencies of the Myostatin locus (P60/P61) in Beijing youji were quite different from those of other tested chicken lines. Frequency of the BB genotype was very high (0.70) while the AA genotype was only 0.033 in 5'-regulatory region (P60/P61) in Beijing youji population. The genotype frequencies (P93/P94) were significantly different among the lines (P < 0.01): frequencies of the EE genotype in Beijing Youji were lower than those in the other lines, while frequencies of the EE genotype in Baierji and Hyline Layer were higher than the rest. Frequency of allele C (P80/P81) in 9 breeds was higher than that of allele D. Frequency of genotype MM (P76/P77) was low, and that of MN was high in 7 breeds.