南江黄羊脂肪型脂肪酸结合蛋白(A-FABP)基因多态性与生长性状关联分析

Association of the adipocyte fatty acid-binding protein(A-FABP) gene polymorphism with some growth traits in Nanjiang Mongolian Grazelle

根据山羊A-FABP mRNA序列设计2对引物扩增南江黄羊A-FABP基因部分外显子3、内含子3和外显子4序列,利用克隆测序的方法寻找南江黄羊A-FABP基因的多态性,采用PCR-RFLP的方法进行多态性检测并与生长性状进行关联性分析。结果显示,在南江黄羊A-FABP基因第3内含子和第4外显子序列上分别发现T143C和T546C2个点突变位点,其中T546C位点为同义突变,这2处突变各自产生3种基因型CC、TC和CC,χ2检验显示,这2个位点均处于中度多态且在南江黄羊群体中分布处于Hardy-Weinberg平衡(P>0.05)。关联分析显示,T143C位点TC基因型公羊个体的成年胸围显著长于TT型(P<0.05);T546C位点CC基因型公羊个体的周岁体长显著长于TT基因型(P<0.05),TC基因型母羊个体的6月龄体质量和胸围均显著长于CC基因型(P<0.05),其余生长性状在不同基因型个体间差异不显著(P>0.05)。结果表明:南江黄羊A-FABP基因第3内含子和第4外显子多态性可能对个体生长性状产生一定的影响。

According to the sequences of adipocyte fatty acid-binding protein （A-FABP） gene mRNA in goat, two pairs of primers P1 and P2 were designed to amplify of partial exon 3 and complete intron 3, exon 4 of Nanjiang Mongolian Grazelle A-FABP. The SNPs were detected by cloning and sequencing,confirmed by technique of PCR- RFLP,and studied the association of polymorphisms of A-FABP gene with some growth traits. There were T143C and T546C two mutations found in the intron 3 and exon 4 in A-FABP gene of Nanjiang Mongolian Grazelle, in which T546C locus mutation was synonymous mutations. The two mutations obtained three genotypes CC, TC and CC respectively. The restriction sites in the two mutations were at Hardy-Weinberg equilibrium by X2 test analysis. Polymorphism information analysis showed that both were moderately polymorphic loci. The association analysis showed that chest circumference with TC genotype in T143C locus was significantly longer than that of TT genotype in adult rams （P〈0.05）, but body length with CC genotype in T546C locus was significantly longer than that of TT genotype in one-year ram （P〈0.05）. Body weight and chest circumference with TC genotype in T546C locus were significantly more weighty and longer than that of CC genotype in 6-month ewe （P〈0.05） ,but there was no significant difference among other growth traits of different genotype. The results suggested that the polymorphisms of intron3 and exon4 of A-FABP gene have some effect on growth trait in Nanjiang Mongolian Grazelle.