线粒体nad5基因在隐藏管状线虫及四翼无刺线虫的序列变异研究

本试验首次研究了小鼠隐藏管状线虫及四翼无刺线虫在线粒体烟酰胺腺嘌呤二核苷酸（NADH）脱氢酶亚单位5基因（nad5）部分序列（pnad5）的种间及种内变异。通过对甘肃兰州地区实验小鼠体内分离的蛲虫样品（LY1-20、LS1-22） nad5基因pnad5进行PCR扩增、克隆及测序分析，研究其遗传变异情况。结果表明，获得隐藏管状线虫pnad5有效序列753 bp，通过序列比对发现来自LY和LS 2家实验动物中心的22个隐藏管状线虫样品之间只存在3个碱基的差异，序列相似性99.60%。获得四翼无刺线虫pnad5有效序列865 bp，2大动物中心20个四翼无刺线虫样品之间没有碱基的差异，序列相似性100%。用软件ClustalX 1.83截取2种鼠蛲虫nad5基因长度共同的序列，通过比对发现2种鼠蛲虫种间差异为53.64%，种间差异显著。研究结果表明，线粒体nad5基因在鼠蛲虫种内相对保守，但种间有着较高的突变率，可作为鼠蛲虫种间鉴定、诊断的遗传标记。

Sequence Variation in Mitochondrial nad5 Gene between Syphacia obvelate and Aspiculuris tetraptera

The objective of this study was to examine sequence variation in mitochondrial NADH dehydrogenase subunit 5 gene (nad5) between and within Aspiculuris tetraptera （A. tetraptera） and Syphacia obvelate （S. obvelate） collected from mice in Lanzhou, China. 42 pinworm samples were collected from mice in two laboratory animal centers in Lanzhou, Gansu province, and their partial nad5 sequences were amplified by PCR. Sequence analysis revealed that the nad5 sequences of A. tetraptera and S. obvelate were 865 and 753 bp, respectively. Sequence similarity in the nad5 sequences within each of the two pinworms were 99.60% and 100%, while the inter-specific sequence difference was 53.64% between A. tetraptera and S. obvelate. These findings demonstrated that nad5 sequences were quite conserved within mouse pinworms, but were significantly different among different pinworm species, indicating that nad5 sequences could be used as the genetic marker for the differentiation of different pinworms.