羊毛尾线虫线粒体rrnL基因部分序列的克隆和进化分析

Cloning and sequence analysis of the partial mitochondrial rrnL gene of Trichuris ovis isolates in China

为探明中国羊毛尾线虫(Trichuris ovis)广东分离株线粒体核糖体大亚基基因(rrnL)的部分序列(prrnL)的遗传变异情况,用prrnL序列构建其与其他毛尾线虫的进化关系;应用聚合酶链反应(PCR)扩增羊毛尾线虫虫株的prrnL,将所获得的序列用ClustalX 1.81程序进行比对,然后用PAUP 4.0 Beta 10程序MP法绘制种系发育树。结果表明:所获得的prrnL序列长度为849～850 bp,种内变异在0～0.8%;13个羊毛尾线虫分离株位于同一分支,羊毛尾线虫prrnL序列种内很保守,种间差异较大(33.4%～36.1%),可作为种间遗传变异研究的标记。

The purpose of this study was to analyze sequence variation in the partial mitochondrial ribosomal large subunit gene （prrnL） among Trichuris ovis （T. ovis） isolates from Guangdong province, China and to study the phylogenetic relationships of T. ovis with other whipworms using prrnL sequences. The prrnL sequences were amplified from individual T. ovis samples by polymerase chain reaction （PCR） method and the obtained prrnL sequences were aligned using ClustalX 1.81. Maximum parsimony （MP） tree was constructed using the software PAUP 4.0 Beta 10. The lengths of all prrnL were 849-850 bp, and differences in prrnL sequences within T. ovis were 0-0.8%. Phylogenetic analyses showed that all T. ovis isolates were clustered in the same clade. The prrnL sequences were quite conserved within whipworm species while inter-species differences （33.4%-36.1%） were obvious. Thus prrnL sequences can be used as a useful marker for the differentiation and identification of different whipworms.