摘要: ZAG基因的功能主要是促进脂肪分解, 减少脂肪含量。文章利用PCR-SSCP和DNA测序技术研究了145头郏县红牛ZAG基因编码区4个位点(Z1、Z2、Z3、Z4)的多态性, 发现Z1、Z3、Z4 位点存在SSCP多态。对不同SSCP带型的对应片段进行了测序分析, 共发现6个新的SNP多态位点(C115T、A3257G、A4013G、T4027C、C4032T、T4120C)。Z3位点处于Hardy-Weinberg平衡状态, Z1、Z4 位点处于非平衡状态。不同基因型与生长发育性状的相关性分析显示, Z4位点上, AC基因型个体的体斜长、胸围、管围、体重指标显著(P<0.05)或极显著(P<0.01), 大于AA、AB基因型个体, 暗示该位点有可能作为郏县红牛生长性状标记辅助选择的标记之一。

Abstract: The main function of ZAG gene is to enable the decomposition of fat, and reduced fat content. In this study, polymorphisms of four loci (Z1, Z2, Z3, Z4) at the coding region of the bovine ZAG gene were detected in 145 Jiaxian red cattle, and polymorphisms were found on Z1, Z3, Z4 loci. The fragments showing different SSCP patterns were sequenced, nd a total of six SNPs (C115T, A3257G, A4013G, T4027C, C4032T, and T4120C) were found. The Z3 locus of ZAG gene was at Hardy-Weinberg equilibrium, while Z1 and Z4 loci of ZAG gene were not at Hardy-Weinberg disequilibrium. The association analysis of different genotypes with some of the growth and development traits showed that the individuals with genotype AC had a larger body length, heart girth, circumference of cannon bone, body weight than the individuals with genotypes AA and AB (P<0.05 or P<0.01, respectively) in Z4 locus. It is suggest that Z4 locus may be one of the marker-assisted selection used as growth traits in Jiaxian red cattle.