东北虎源蛔虫线粒体cox1基因序列进化分析研究

Phylogenetic analysis of mitochondrial cox1 gene of ascarid isolated from tigers

为了解东北虎源蛔虫与其他蛔虫的种群遗传关系,本研究对湖南省长沙生态动物园东北虎粪便中采集的蛔虫成虫的线粒体DNA中细胞色素I(cox1)基因序列进行扩增,将测序结果与GenB ank中登录的其他蛔虫cox1序列进行对比及种系发育树分析。结果显示,来自长沙生态动物园7个东北虎蛔虫样品cox1序列长度基本一致,为413 bp^414 bp,与猫弓首蛔虫同源性最高,达98.4%以上,而且系统进化分析显示所有样品均与猫弓首蛔虫位于同一分支。该结果表明,pcox1序列种内相对保守,种间差异较大,因此可以作为猫科弓首蛔虫的种间遗传变异研究的分子遗传标记,从而为蛔虫的群体遗传研究奠定了基础。

The objectives of the present study were to examine sequence variation of the mitochondrial cytochrome c oxidase subunit 1 gene （coxl） in ascarid of Manchurian tiger from Changsha ecology zoo. The cox1 were amplified from 7 samples, respectively, and the cox1 sequences were aligned using the ClustalX2.0. The results showed that the lengths of coxl sequences were 413 bp to 414 bp. The constructed phylogenetic tree revealed that the 7 Hurlan isolates were clustered into the same clade of the Toxocara cati reference strains available in GenBank. As the result, all the 7 samples were identified as T.cati and coxl sequences could be used as a genetic marker for population genetic studies of ascarid. These data provided foundation for further studies of molecular epidemiology of T. cati, and for diagnosis of the resultant disease.