中文摘要：

目的通过分析旋毛虫线粒体基因分子标记,研究我国旋毛虫地理株间的遗传变异与系统发生关系。方法应用旋毛虫线粒体核糖体小亚基DNA（mitochondrial small subunit ribosomal DNA,mtSSU）和线粒体细胞色素氧化酶Ⅰ基因（mitochondria cytochrome coxidase,COΙ）为分子标记,分别对我国7个旋毛虫地理株扩增后进行双向测序,利用DNAMAN软件将测序结果和GenBank中相应序列进行比对研究,并使用MEGA4.0程序包构建系统进化树。结果 PCR对7个旋毛虫地理株分别扩增出了649bp（mtSSU）和419bp（COΙ）的DNA片段,7个地理株的DNA片段与GenBank中T.spiralis的相应片段相比存在一定差异,其中mtSSU基因有4个变异位点（248、293、537和539位）,而COI基因仅存在2个变异（273和382位）,所有变异均为T-C或C-T的转换;进化树显示南阳株和云南株位于比较近的分枝,而西安株、广西株及西藏株亲缘关系较近。结论我国7个旋毛虫地理株的遗传变异较小,亲缘关系较近。

英文摘要：

Genetic variation and phylogenetic relationship of Trichinella isolates in China were studied by analysis of mitochondrial cytochrome coxidase gene（COI） and mitochondrial small subunit ribosomal DNA（mtSSU） as molecular markers.The DNA fragments from the 7 Trichinella isolates from China were amplified by PCR-based methods.The genetic distances and sequence similarity were compared with the corresponding sequences of T.spiralis in GenBank by using the DNAMAN software.The phylogenetic trees were constructed by MEGA 4.0 with Neighbor-joining method.The results showed that the DNA fragments with 649bp（mtSSU）and 419bp（COΙ） from the 7 isolates were amplified,and some different with that of T.spiralis in GenBank.The mtSSU gene had four variable sites（248,293,537,and 539）,COI gene had only two variable site（273 and 382）,and all the type of genetic variations were conversion of C-T or T-C.Based on the phylogenetic tree,Nanyang and Yunnan isolates were close,while the phylogenetic relationship of Tibet,Xi＇an and Guangxi isolates were closer.The results demonstrated that the genetic variation of the 7 T.spiralis isolates from China was small and their phylogenetic relationship was close.