藏绵羊MHC-DRB1基因第3外显子的PCR-SSCP检测及其序列分析  

PCR-SSCP Detection and DNA Sequence Analysis of MHC-DRB1 Gene Exon 3 in Tibetan Sheep

作　　者：徐飞[1] 成述儒[1] 刘秀[1] 王继卿[1] 胡江[1] 罗玉柱[1] 

机构地区：[1]甘肃农业大学甘肃省草食动物生物技术重点实验室/动物科学技术学院,兰州730070

出　　处：《农业生物技术学报》2011年第5期873-880,共8页Journal of Agricultural Biotechnology

基　　金：国家科技支撑计划项目(No.2009BAC53B06;No.2007BAD52B05);国家高技术研究发展计划("863"计划)项目(No.2006AA10Z196);甘肃省农业生物技术专项(No.GNSW-2009-24);国家农业科技成果转化资金项目(No.2010GB2G100491)

摘　　要：为了研究藏绵羊DRB1基因第3外显子多态性,确定其等位基因数、核苷酸多态位点、变异类型和各等位基因间的遗传关系,本研究采用PCR-SSCP方法,分析了500只藏绵羊(Ovis aries)DRB1基因第3外显子多态性,并对不同等位基因进行克隆和测序。结果表明,藏绵羊DRB1基因第3外显子表现了8个等位基因,8个单倍型序列分析发现了15个核苷酸多态位点,与GenBank序列对比分析,有7个DRB1的等位基因是首次发现。8个DRB1第3外显子的单倍型序列NJ系统发育树呈2支分化趋势。3个种群藏绵羊中B均为优势等位基因,该位点PIC>0.5,为高度多态且显著偏离Hardy-Weinberg平衡状态。研究认为,藏绵羊DRB1基因第3外显子具有丰富的多态性;藏绵羊DRB1基因最初是由2个等位基因突变分化成两大类等位基因。In order to study DRB1 gene exon 3 polymorphism in Tibetan sheep, The number of alleles, single nucleotide polymorphisms（SNPs） sites, variation type, the genetic relationship and evolutionary significance of the alleles had been analyzed. Variation in the 500 Tibetan sheep （Ovis aries） DRB1 gene exon 3 was investigated by PCR-SSCP method, followed by cloning and DNA sequencing. The results showed that 8 alleles were identified, 15 nucleotide polymorphism sites were identified in 8 sheep DRB1 gene haplotypes and 7 novel DRB1 exon 3 alleles were found comparison with GenBank sequences. The phylogenetic tree results showed that the 8 haplotypes of Tibetan sheep DRB1 exon 3 could divide into two clusters. Allele B was the most common allele in three Tibetan sheep populations, and that allelic and genotype frequency were significantly deviated from Hardy-Weinberg balanced. The polymorphism was higher with PIC more than 0.5 at DRB1 gene exon 8 in three Tibetan sheep populations. The results suggest that Tibetan sheep DRB1 gene exon 3 has high level of sequence polymorphism,Tibetan sheep DRB1 gene is differentiated into two major category alleles from two mutant alleles at first.

关 键 词：PCR-SSCP DRB1基因 遗传多态性 藏绵羊 

分 类 号：S823[农业科学—畜牧学]