中国西北部地区多房棘球绦虫cox1基因多态性研究

Genetic polymorphism of Echinococcus multilocularis in northwestern China inferred from cox1 gene sequences

目的分析四川省西部多房棘球绦虫遗传多态性,对我国西北部地区多房棘球绦虫不同地理亚群的亲缘关系和基因多样性进行探索。方法采用线粒体cox1基因完整序列对四川省西部藏区64份来源于不同生物宿主的多房棘球绦虫样本进行遗传多态性分析,同时收集GenBank数据库中来源于中国不同地区的多房棘球绦虫的cox1基因序列,比对分析不同地理来源分离株的遗传多态性特征。结果(1)64份样本共检出5个单倍型,均属于多房棘球绦虫亚洲亚群。单倍型多样性与低核苷酸多样性分别为0.179±0.064和0.00013±0.00005。(2)搜索GenBank数据库,结合本研究中序列信息,共获得181条来源于四川、青海、新疆和内蒙古的多房棘球绦虫cox1基因序列,获得45个单倍型。单倍型网络图呈现星状排列,中央单倍型为四川、青海和新疆三地共有,其余单倍型为各地独有。构建的ML系统发育树分支与单倍型地理分布相对应,形成较为明显的地理结构。结论四川省西部地区多房棘球绦虫遗传多样性较低,寄生于不同宿主的多房棘球绦虫间无明显遗传差异。我国不同地区多房棘球绦虫遗传变异特征的分析确证需要进一步的数据支撑。

Objectives To analyze the genetic polymorphism of Echinococcus multilocularis in Western Sichuan Province and to explore the genetic relationships and diversity of E.multilocularis in different places in northwestern China.Methods The entire mitochondrial cox1 genes sequences were used to analyze genetic variances in 64 samples from different hosts in the Tibetan area of Western Sichuan Province.cox1 gene sequences of E.multilocularis from different regions in China were collected from the GenBank database to analyze the genetic polymorphism of isolates with different geographical sources.Results(1)A total of 5 haplotypes were detected in 64 samples,all of which belong to the Asian cluster.Haplotype diversity was 0.179±0.064 and nucleotide diversity was 0.00013±0.00005.(2)Based on a search of GenBank and sequence information obtained in this study,a total of 181 cox1 gene sequences of E.multilocularis from Sichuan,Qinghai,Xinjiang,and Inner Mongolia were obtained,and 45 haplotypes were identified.The haplotype network had a star-shaped pattern.The central haplotype is shared by Sichuan,Qinghai,and Xinjiang,and the remaining haplotypes are unique to each region.The ML phylogenetic tree branches corresponded to the haplotype geographic distribution,which had a clear phylogeographic structure.Conclusion E.multilocularis has little genetic diversity in Western Sichuan Province.There are no significant genetic differences among E.multilocularis isolates from different hosts.More genetic data are required to analyze and confirm the genetic diversity of E.multilocularis in different areas of China.