Abstract: Objective　To analyze the sequences of the cytochrome C oxidase subunit I (Cox1) gene of various Echinococcus granulosus genotypes that are currently recorded in the GenBank database, so as to investigate the genetic variation and differentiation of the E. granulosus genotypes across the world. Methods　The sequences of the Cox1 gene of various E. granulosus genotypes that are currently recorded in the GenBank database were collected, and the same sequences of the Cox1 gene identified from a region were excluded. The mutation sites among the Cox1 gene sequences were identified and a phylogenetic tree was created based on the Cox1 gene. Results　Transversion mutation was the predominant type of mutation in the Cox1 gene of E. granulosus. The same Cox1 gene sequence was found in E. granulosus G1, G6 and G7 genotypes isolated from various geographical locations across the world, with the corresponding GenBank accession numbers of KY766891, MH300971 and MH301007, respectively. Phylogenetic analysis revealed that E. granulosus G10 genotype had a remarkable geographical aggregation. Conclusions　E. granulosus G1, G6 and G7 genotypes have primitive Cox1 gene sequences. There is a geographical aggregation of the E. granulosus G10 genotype in the phylogenetic tree, which has a tendency towards reproductive isolation.

Key words: Echinococcus granulosus, Genotype, Phylogenetic analysis, Cytochrome C oxidase subunit I

摘要： 目的　分析GenBank数据库中公布的细粒棘球绦虫各基因型细胞色素C氧化酶亚基Ⅰ（Cox1）基因序列，探索细粒棘球绦虫各基因型在全球不同地区的遗传变异及分化情况。方法　收集GenBank数据库中公布的不同基因型细粒棘球绦虫Cox1基因序列，排除同一地区内相同基因序列，寻找收集的基因序列间的变异位点并构建进化树，观察不同地区细粒棘球绦虫各基因型的地域聚集性及原始基因序列。结果　通过对Cox1基因序列变异位点统计，发现细粒棘球绦虫Cox1基因突变类型以颠换为主，G1、G6、G7基因型在其分布的各地区均有相同Cox1基因序列，基因序列相对应的GenBank登录号分别为KY766891、MH300971、MH301007。系统进化分析发现G10基因型存在明显地域聚集性。结论　细粒棘球绦虫G1、G6、G7基因型存在原始Cox1基因序列；G10基因型进化树中出现地域聚集性，存在生殖隔离趋势。 　

关键词: 细粒棘球绦虫, 基因型, 进化分析, 细胞色素氧化酶亚基Ⅰ