湖北钉螺COI序列差异的扩展研究  

Extended study on CO I sequence variation of Oncomelania hupensis

作　　者：关飞[1] 牛安欧[1] 韩庆霞[1] 陈琼荣[1] 

机构地区：[1]华中科技大学同济医学院病原生物学系,武汉430030

出　　处：《国际医学寄生虫病杂志》2011年第1期23-27,共5页International JOurnal of Medical Parasitic Diseases

基　　金：中央高校基本科研业务费资助（2010QN020）

摘　　要：目的研究中国2l株湖北钉螺细胞色素氧化酶I（cytochrome oxidase I，COI）基因序列差异和各地域株的亚种分化。方法收集中国4省7地湖北钉螺标本，提取基因组DNA后，PCR扩增COI基因部分片段并进行序列测定。加入原有14株钉螺COI序列，用ClustalX进行序列比对后输入MEGA软件计算遗传距离，并分析序列集变异情况。采用距离法构建系统进化树。结果所有21株标本经过序列比对得到一致性长度为611bp。序列集中变异位点为19．3％。编码的203个氨基酸中仅有1个氨基酸的差异。21株钉螺平均遗传距离为0．0526，其中四川、云南株与其他地域株之间差异较大，为0．1296～0．1572，其余两两之间的距离均〈0．06。采用邻接法和非加权组平均法两种方法构建系统进化树，拓扑结构基本一致，四川、云南株聚为一支，其余株位于另外分支，且湖北赤壁株及湖北远安、钟祥株显示出特异性。结论中国湖北钉螺COI基因存在差异。原有分类中滇川、福建、指名、广西亚种成立。湖北赤壁株似为独立亚种。Objective To study the cytochrome oxidase I sequence difference and subspecies evolution of 21 strains of Oncomelania hupensis in China. Methods Samples were collected from 7 sites in 4 provinces. Genomic DNAs were extracted from each strain and then used as template for CO I fragment amplification by PCR. The amplified product was sequenced with primers in two directions respectively. The 7 sequences, together with other 14 CO I sequences were aligned with Clustal X and then pair-wise distances were accounted using MEGA software. Phylogenetic trees were reconstructed based on distance methods. Results The CO I sequences of all 21 stains had a length of 611 bp after a global alignment, 118 bp （ 19.3% ） of which were variable sites. The DNA sequence was translated into 203 amino acids with 1 different amino acid. Among the 21 strains, mean evolutional distance was 0.0526. The distance between Sichuan, Yunnan and oth- er strains was 0. 1296 - 0. 1572, much more than others. The phylogenetic trees constructed with neighbourjoining（NJ） and unweighted pair group method with arithmetic mean （UPGMA） showed similar topological structure, strains of Sichuan and Yunnan clustered in one clade, while others were in another elade. There were some differences among the strains of Chibi, Yuan＇an and Zhongxiang from Hubei Province. Conclusion The CO I sequences of O. hupensis in China showed significant variation. Hubei-Chibi seemed to be an independent subspecies, except 4 existent subspecies of O. hupensis robertsoni, O. hupensis guangxiensis, O. hupensis tangi, O. hupensis hupensis.

关 键 词：湖北钉螺 细胞色素氧化酶I 系统发育 

分 类 号：R394[医药卫生—医学遗传学]