A-FABP和H-FABP[WTHZ]基因多态位点及聚合基因型对白耳鸡胸肌肌内脂肪含量（IMF）的效应分析*

 研究采用PCR SSCP方法检测白耳鸡A-FABP基因外显子1和H-FABP基因内含子2区域单核苷酸突变位点，并分析多态位点不同基因型及聚合基因型与90日龄胸肌肌内脂肪（IMF）含量的关联。结果在A-FABP基因外显子1和H-FABP基因内含子2处分别检测到C51T和C1523T突变，突变均产生3种基因型（TT/TC/CC），各等位基因频率均处于H-W平衡状态。关联分析和基因型效应分析结果表明多态位点与胸肌IMF含量显著相关（P<0.05），A-FABP基因和H-FABP基因不同基因型对白耳鸡胸肌IMF含量的加性效应分别为0.265和0.207，显性效应分别为0.042和0.021，主效应指数（MEI）分别为8.99%和6.93%。TT为两种有利单基因型，对胸肌IMF含量具有显著的正向贡献率（CP：8.23%，6.17%，P<0.05），其对应的个体胸肌IMF含量为3.350%和3.286%。两种有利单基因型聚合个体TT/TT的胸肌IMF含量为3.660%，显著高于其他基因型聚合个体（P<0.05）。

Effect of Polymorphism Sites and Pyramiding Genotypes of A-FABPand H-FABP Genes on Baier Chicken Muscle Intramuscular Fat (IMF) Contents

PCR SSCP method was used to identify the polymorphism sites in exon 1 domain of A-FABP gene and intron 2 domain of H-FABP gene. Associations between the founded polymorphism sites as well as pyramiding genotypes and intramuscular fat (IMF) contents in muscles were tested by least square analysis. Two polymorphism sites, C51T and C1523T were identified, and both had three genotypes (TT/TC/CC). The allele frequencies at the locus were in Hardy Weinberg equilibrium (P>0.05) in BAI populations.The association analyis showed that the founded polymorphism sites of A-FABPgene and H-FABPgene had effects on IMF contents in muscles. The additive effects of different genotypes were respectively 0.265 and 0.207, and the dominant effects were 0.042 and 0.021. The major effect indices(MEI)were 8.99% and 693%,respectively. The TTs were two advantageous genotypes, and had significantly positive contribution percentage (8.23%, 6.17%, P<0.05) to IMF contents. The IMF contents of individuals with TT genotypes for A-FABPgene and H-FABPgene were 3.350% and 3286%. The pyramiding genotype TT/TT had higher IMF contents (P<0.05) than that of other pyramiding genotypes.