Liu G H, Li B, Li J Y, Song H Q, Lin R Q, Cai X Q, Zou F C, Yan H K, Yuan Z G, Zhou D H, Zhu X Q
State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
J Helminthol. 2012 Dec;86(4):479-84. doi: 10.1017/S0022149X11000757. Epub 2011 Dec 12.
The present study examined sequence variation in four mitochondrial (mt) genes, namely cytochrome c oxidase subunits 1 (cox1) and 2 (cox2), and NADH dehydrogenase subunits 1 and 2 (nad1 and nad2) among Clonorchis sinensis isolates from different endemic regions in China, and their phylogenetic relationships with other zoonotic trematodes were reconstructed. A portion of the cox1 and cox2 genes (pcox1 and pcox2), and nad1 and nad2 genes (pnad1 and pnad2) were amplified separately from individual liver flukes by polymerase chain reaction (PCR) and the amplicons were subjected to sequencing from both directions. The intra-specific sequence variations within C. sinensis were 0-1.6% for pcox1, 0-1.4% for pcox2, 0-0.9% for pnad1 and 0-1.0% for pnad2. Phylogenetic analyses based on the combined sequences of pcox1, pcox2, pnad1 and pnad2 revealed that all the C. sinensis isolates grouped together and were closely related to Opisthorchis felineus. These findings revealed the existence of intra-specific variation in mitochondrial DNA (mtDNA) sequences among C. sinensis isolates from different geographic regions, and demonstrated that mtDNA sequences provide reliable genetic markers for phylogenetic studies of zoonotic trematodes.
本研究检测了来自中国不同流行地区的华支睾吸虫分离株中四个线粒体（mt）基因，即细胞色素c氧化酶亚基1（cox1）和2（cox2）以及NADH脱氢酶亚基1和2（nad1和nad2）的序列变异，并重建了它们与其他人畜共患吸虫的系统发育关系。通过聚合酶链反应（PCR）分别从单个肝吸虫中扩增出cox1和cox2基因的一部分（pcox1和pcox2）以及nad1和nad2基因（pnad1和pnad2），并对扩增产物进行双向测序。华支睾吸虫种内pcox1的序列变异为0 - 1.6%，pcox2为0 - 1.4%，pnad1为0 - 0.9%，pnad2为0 - 1.0%。基于pcox1、pcox2、pnad1和pnad2组合序列的系统发育分析表明，所有华支睾吸虫分离株聚在一起，且与猫后睾吸虫密切相关。这些发现揭示了来自不同地理区域的华支睾吸虫分离株中线粒体DNA（mtDNA）序列存在种内变异，并证明mtDNA序列为人畜共患吸虫的系统发育研究提供了可靠的遗传标记。
