结膜吸吮线虫形态学鉴定及基于cox1基因的系统发育分析

Morphological Identification and Phylogeny Analysis based on Mitochondrial cox 1 Gene Sequences of Thelazia callipaeda

对从贵州省正安县不同乡镇的结膜吸吮线虫（T.cp）感染者中获得多条虫体进行形态学鉴定,并对其线粒体cox1基因进行测序,结合Gen Bank上5条同源序列,对不同地域的8个个体进行了系统发育分析。结果显示正安县T.cp感染者眼部分离的虫体在光镜下形态特征与其他地区虫体特征基本一致,进一步HE染色发现显示其体壁由角皮层、皮下层和纵肌层组成,为多肌型线虫;而正安小雅、桴焉、碧峰3个相邻乡镇样本cox1基因序列同源性为100%,与罗马尼亚（KP087796.1）、塞尔维亚（KJ433983.1）结膜吸吮线虫cox1基因序列在同一分支;而安常、新洲样本与日本Oita（AB538283.1）样本亲缘关系较近。因此,cox1基因在不同地域来源结膜吸吮线虫间则存在一定种内和地域差异,可作为不同地域来源的亚种结膜吸吮线虫种群遗传变异的有效分子标记。

A series of Thelazia callipaeda derived from different towns of Zheng＇an,Guizhou were observed based on morphological identification and sequenced by mitochondrial cox1 gene.Combined 5 homologous sequences downloaded from Gen Bank,8 individuals derived from different regions were compared in this study.The results indicated that morphological characteristics under light microscope of T.cp derived from patients in Zheng＇an were basically consistent with the characteristics from other regions,and HE staining showed that the insect body wall contained three layers：the angle of cortex,subcutaneous layer and longitudinal muscle layer,which characteristics were conformed to the multiple muscular type nematode.Homology of the Cox1 gene sequenceof T.cp derived from three adjacent towns Xiaoya,Yanfu,Bifeng showed 100%similarity,and the phylogenetic trees inferred from cox1 showed T.cp isolated from Romania（KP087796.1）,Serbia（KJ433983.1）was in the same branch with that of Zheng＇an.Moreover,samples derived from Anchang,and Xinzhou showed near genetic relationship with that of Oita,Japan（AB538283.1）.This result indicated that cox1 gene of T.callipaeda from different areas showed genetic diversity andregional differences,and mightbe thesuitable markers for detecting the genetic variation about the population of T.callipaeda subspecies.