Studies On Polymorphism Of Myf5 Gene In Gushi-anka Chickens F₂ Resource Population

A resource population was constructed using F₂ design with Gushi chicken which is the excellent Chinese meat-egg chicken and Anka chicken which is the fast and large broiler chicken in this study,Myf5 gene polymorphisms had been studied in F₂ resource population by PCR-SSCP, DNA sequencing, PCR-RFLP and CRS-PCR-RFLP,the relationships between the variable sites and the economic traits were valued by the least-squares analysis. The main results were as follows:In this study, CRS-PCR-RFLP technique had been used to detect SNPs in the exon region of Myf5 gene, MspI enzyme site was introduced into this pair of primers,compared with the original sequence,a base mutation has been desiged in order to include this enzyme site. the site is synonymous mutation by sequencing and sequence alignment that had not caused changes of amino acid sequence. allele A was the dominant gene, AB genotype was the dominant type in the population. PIC was 0.375, belonged to moderate polymorphism,and heterozygosity was 0.504, the groups was significant deviation from hardy-weinberg equilibrium (P <0.01) byχ2 test. The association between different genotypes and the recorded economic traits was analyzed. The result showed that Myf5 exon1 MspI polymorphism, which was completely linked, was significantly associated with 4 weeks bodyweight (BW4), 12 weeks bodyweight(BW12),12 weeks body slanting length(BSL12),(P<0.05),2 weeks bodyweight (BW2,P<0.01).The primer was designed in the coding region of the first exon, the PCR products were sequenced directly.two variable sites were detected, namely A533G and T632C( NC₀06088) , the two sites were synonymous mutation by sequencing and sequence alignment that had not caused changes of amino acid sequence. allele C was the dominant gene, CD genotype was the dominant type. PIC was 0.373, belonged to moderate polymorphism,heterozygosity was 0.497,the groups was significant deviation from hardy-weinberg equilibrium (P <0.01) byχ2 test.The association between different genotypes and the recorded economic traits was analyzed.The result showed that Myf5 exon1 PCR-SSCP polymorphism, which was completely linked, was significantly associated with 8 weeks shank girth (SG8), skin fat thickness (SFT),carcass weight ratio(CWR),creatine kinase (CK),leg region(LR) (P<0.05),high density lipoprotein (HDL),Caecum length(CL) (P<0.01).The relationships between different genotype combinations and important economic traits in Myf5 gene were analysed,the results showed that different genotype combinations were significantly associated with birth weight, 8 weeks bodyweight(BW8), 10 weeks bodyweight(BW10), 12 weeks bodyweight(BW12), carcass weight(CW), breast muscle weight(BMW), leg weight(LW), Caecum length(CL), high density lipoprotein (HDL) ,lactate dehydrogenase(LD), shear force values of breast muscle(BSF), Water loss rate of leg muscle(LWLR).These observations suggested that the polymorphisms in Myf5 gene had significant effects on the early growth traits of chicken. The polymorphisms were also associated with other important economic traits,so Myf5 gene can be considered as candidate genes for further analysis.