Studies On Meat Quality Through The Method Of Candidate Gene In Chicken

Great progress has been made in poultry breeding in the past 20 years. While daily gaining of body weight and the ratio of meet to food and resistance to disease in chicken have been improved considerately, the intensive selection in chicken breeding has resulted in some negative effects, such as the degrade of quality and flavor of meat. The problem has drawn the attention of breeders all over the world and some progress has been made, but there is almost no improvement on high percentage of hypoderrnal fat and abdominal fat as well as low percentage of intramuscular fat in breast and legs in broilers. There is a view that intramuscular fat (IMF) was in positive correlation with meat flavor and succulency, especially tenderness of meat. It is important for increasing JMF and controlling fatty deposition and improving meat quality to understand the development and growing mechanism of fatty tissue.In this study, 557 samples were selected from F2 chickens derived from broilers crossing to silky. Extracellular fatty acid binding protein (EX-FABP) gene and myogenin gene was served as a candidate gene for meat qulity. The 5?region and all exon of EX-FABP gene were amplified with twelve pairs of primers and then were detected single nucleotide polymorphism (SNP) by the method of single strand composition polymorphism (SSCP). The result of SSCP shown there are eight nucleotides mutation at ? 807 A-G~ -1805 C-A.. -1011 I-C.. 659 T-C.. 924 C-I. 968 CA-TO.. 1985 C-T and ?000 C insert respectively. The promoter of myogenin gene was amplified with four pairs of primer and then was detected SNP by the method of SSCP. The result of SSCP shown there are three nucleotides mutation at ?18 T-C~ -224 G-A and ?60 C insert respectively.The result of least square analysis shown the BB genotype of PCR amplification by the second primer of EXFABP have higher abdominal fat percentage and HH genotype of PCR amplification by the second primer of EXFABP have lower abdominal fat percentage than others genotype, and the difference was very significant (P<0.001). But carcass, breast muscle, leg muscle weight had no significant (P>0.05) difference among different genotype. It implied that extracellular fatty acid binding protein gene could be a candidate locus or linked to a major gene to significantly affect abdominal fat traits in chicken. The DNA marker we discovered in this experiment can be used to molecular marker assist selection to chicken fat trait.