中文摘要：

基于PCR-SSCP和克隆测序技术,分析了西北6个绵羊品种的群体内和群体间的遗传变异,通过对DNA序列的多重比对,得出A、B、C3种单倍型,在D-loop区内的碱基替换全部为转换;绵羊mtDNA D-Loop区中存在着明显的长度变异,引起变异原因主要是由于1个或几个碱基或串联重复基元序列的插入（或缺失）造成的,不存在绵羊品种特异性;本试验研究的绵羊在各个不同片段中所扩增出的A、B、C3种单倍型基本一致,但不是完全连锁,存在着微小的差异;用NJ法构建了系统进化树,可明显看出中国6个绵羊品种3种单倍型的分类情况,单倍型树表明新疆的巴音布鲁克羊和卡拉库尔羊之间的遗传关系最近。

英文摘要：

The study analyzed the genetic variation within population and among populations of 6 sheep breeds based on PCR-SSCP and subsequent clone sequencing protocols.Comparison of the mtDNA sequences showed that all the replacement substitutions of base pairs in D-Loop between the hyplotypes A,B and C,are transitions alone;length variation in insertion or deletion of base pair or tandemly repeated sequence in D-Loop was found in the six sheep breeds;hyplotypes A,B and C were basically in the same linkage in the six sheep breeds with a few exceptions;phylogenetic trees of NJ support the classification of three hyplotypes in the six sheep breeds in China and Bayinbuluke sheep and Kalakuer sheep had a closer relationship compared to others.