哈萨克马的DRA与DQA基因的SSCP检测及序列分析

PCR - SSCP Detection and DNA Sequence Analysis of DRA and DQA Gene in Kazakh Horse

【目的】了解哈萨克马ELA-DRA*exon2、ELA-DQA*exon2的等位基因分布及其特性,为马的抗病育种提供理论基础。【方法】采用聚合酶链式反应-单链构象多态性(PCR-SSCP)方法检测哈萨克马ELA-DRA*exon2、ELA-DQA*exon2的等位基因分布,并对不同等位基因的核苷酸与氨基酸序列进行分析。【结果】在47匹哈萨克马中,ELA-DRA* exon2有3个等位基因,其中两种等位基因在纯合子中被检出,另外一种等位基因在杂合子中被检出;ELA-DQA* exon2有7个等位基因,且都以纯合子被检出,通过核苷酸序列比对发现其中5个为新等位基因。【结论】ELA-DRA*exon2、ELA-DQA*exon2的各每位基因序列分析结果表明,发生非同义替换的多态位点均主要分布在抗原结合位点对应的编码序列中。

[ Objective ] The paper aimed to know the allele -frequency distribution and character of ELA - DRA ＊ exon2 and ELA - DQA ＊ exon2 in Kazakh horse so as to lay a good theoretical foundation for the breeding of disease - resistant horses. [ Method ] ELA - DRA ＊ exon2 and ELA - DQA ＊ exon2 in Kazakh horse were genotyped by polymerase chain reaction- single strand conformation polymorphism （PCR -SSCP） methods. Both the nucleotide sequences and the amino acid sequences of the different alleles were analyzed in these horses. [ Result and Conclusion ] The results showed that three alleles of ELA - DRA ＊ exon2 were detected in 47 Kazakh horses ： two kinds of alleles were detected in homozygotes, the other allele was detected in heterozygotes; seven alleles of ELA - DQA ＊ exon2 were detected in 47 Kazakh horses： all alleles were detected in homozygotes, five alleles of them were new alleles through nucleotide sequences alignment. The estimation of the nucleotide sequences and the amino acid sequences of the different alleles in the ELA - DRA ＊ exon2 and ELA - DQA ＊ exon2 showed that there was a higher ratio of non - synonymous substitutes in the peptide - binding site （PBS） region.