Genetic diversity of CO I in Oncomelania hupensis snails (Gastropoda: Rissooidea) along the middle and lower reaches of the Yangtze River
长江中下游地区湖北钉螺线粒体CO I 基因遗传变异研究

The Oncomelania hupensis snail samples were collected from eight locations including Dantu and Hanjiang of Jiangsu, Pinghu of Zhejiang, Wuchang of Hubei, Yugan and Pengze of Jiangxi, Anqing and Guichi of Anhui, in five schistosomiasis-endemic provinces along the middle and lower reaches of the Yangtze River. The genomic DNA of the snails were extracted, and CO I gene fragments were amplified by PCR, then purified and sequenced. Sequences were analyzed with software ClustalX Version 1.81. The genetic distances of the various regions were calculated using Kimura 2-parameter method and phylogenetic trees were constructed with NJ and MP methods in software MEGA Version 4.0. Following the editing of ClustalX, a total of 701 homologous sites were obtained, and the content of A/T (60.4%) was higher than C/G (39.6%). The mean genetic distance among all sequences was 0.025. The phylogenetic tree showed that the snails from Dantu of Jiangsu, Wuchang of Hubei, Yugan of Jiangxi, Anqing and Guichi of Anhui were clustered, and snails from other three sites developed another cluster. However, there was variation observed in the phylogenetic tree constructed by the two methods. It is indicated that there is distinct genetic diversity in CO I genes of O. hupensis snails along the middle and lower reaches of the Yangtze River in China.