Abstract: We used the Duolang sheep as object in this study，researched the genetic diversity of mitochondrial D-loop region of sheep，layed the foundation for the study of the origin and evolution of Duolang sheep. The results showed that the length of mtDNA D-loop is 945~1 039 bp.　The percentage of A, T, G, C was 29.4%, 27.7%, 17.7% and 25.1%, respectively. A+T was 571%, 　G+C was 42.8%. The study acquired 26 haplotypes, 56 polymorphic sites. Single polymorphism sites and concision information sites were 42 and 14 respectively. The average number of nucleotide differences k is 5.289, nucleotide diversity P is 0.024 15, which indicated that genetic diversity of Duolang sheep was low and key protection measures should be taken. Furthermore, it was also found that Duolang sheep experienced population expansion, there might be D or E lineage of the matrilineal origin besides A, B and C lineage.

Key words: Duolang sheep, mtDNA D-loop region, genetic diversity

摘要： 以多浪羊为研究对象，分析绵羊线粒体D-loop区的遗传多样性，为研究多浪羊的起源和进化历史奠定基础。结果显示，多浪羊线粒体DNA D-loop序列长度为945~1 039 bp，A、T、G和C含量分别为29.4%、27.7%、17.7%和25.1%，其中A+T为57.1%，G+C为42.8%。研究获得了26种单倍型，56个多态位点，其中单一多态位点42个，简约信息位点14个。平均核苷酸差异数k为5.289，核苷酸多样度Pi为0.02 415，核苷酸多样度较低，说明多浪羊的遗传多样性贫乏，应采取重点措施予以保护。另外研究发现多浪羊经历过群体扩张，其母系起源除A、B和C世系外，可能存在D或E世系。

关键词: 多浪羊, mtDNA D-loop区, 遗传多样性