高原型藏绵羊KAP 基因单核苷酸多态性分析

试验旨在寻找角蛋白辅助蛋白(keratin-associated proteins，KAP)基因与产毛性状相关的多态位点，为藏绵羊产毛性状的分子标记提供理论依据。采用PCR-SSCP技术对高原型藏绵羊角蛋白辅助蛋白基因家族中KAP 3.2、KAP 7基因部分序列和KAP 8基因外显子进行多态性分析。结果表明，3个基因座都存在多态性，均检测到AA、AB和BB 3种基因型。KAP 3.2基因以A等位基因为优势等位基因，AA基因型为优势等位基因型；KAP 7和KAP 8基因均以B等位基因为优势等位基因，BB基因型为优势等位基因型。高原型藏绵羊在KAP 3.2和KAP 8基因座达中度多态，而在KAP 7基因座为低度多态，在KAP 3.2和KAP 8位点上基因型频率处于Hardy-Weinberg非平衡状态。测序分析结果表明，KAP 3.2和KAP 8基因上分别存在1个C→T（271 bp）和1个T→C(1122 bp）的突变，均属于同义突变，KAP 7基因5′调控区存在1个T→C（102 bp）的突变。

Analysis on Single Nucleotide Polymorphisms of Keratin-associated Proteins Gene in Plateau Tibetan Sheep

This study was conducted to analyze the polymorphisms of keratin-associated proteins (KAP) gene and aid to provide a theoretical foundation for molecular marker of wool production performance in tibetan sheep. The polymorphisms of partial sequence of KAP 3.2, KAP 7 and the exon of KAP 8 in plateau tibetan sheep were analyzed using PCR-SSCP. The results showed that there were polymorphisms in three gene locus, and were detected three genotypes (AA, AB, BB). The frequency of A allele was obviously higher than that of B allele, and the frequency of AA genotype was higher than AB and BB at KAP 3.2 locus, while the frequency of B allele was higher than A allele, and the frequency of BB genotype was higher than AA and AB at other two gene loci. The polymorphism was medium in KAP 3.2 and KAP 8 gene loci, while low in KAP 7 locus. The frequencies of genotype were deviated from the Hardy-Weinberg disequilibrium at KAP 3.2 and KAP 8 gene loci. The sequencing results showed that there was one mutation at 271 bp of KAP 3.2 and 1122 bp of KAP 8 gene, respectively, and there was one mutation at 102 bp of upstream regulatory region of KAP 7 gene. 