鸡蛔虫黄山市分离株的形态学和分子特征分析

Morphological and molecular characteristics of Ascaridia galli isolates from Huangshan area

目的通过对鸡蛔虫的形态学和分子特征分析,进一步明确鸡蛔虫的分类地位。方法对分离自安徽省黄山市的鸡蛔虫分离株在光学显微镜和扫描电子显微镜下分别进行形态学上的观察;PCR扩增鸡蛔虫COⅠ、ITS基因,分别利用其核苷酸序列构建鸡蛔虫与其他线虫的系统发育分析树。结果形态学观察鸡蛔虫死后固定虫体呈乳白色,雌虫的尾部尖直而雄虫的尾部卷曲。虫体头部唇瓣3个,大小几乎相等;雄虫尾部具有乳突10对;所获得的鸡蛔虫COⅠ和ITS基因序列长度分别为655 bp和1034 bp;鸡蛔虫黄山市分离株与其他国家/地区的鸡蛔虫参考株同源性很高,COⅠ最高达100%,ITS最高达99.9%,并与其他鸡蛔虫在系统发育树上聚集在同一支系。结论鸡蛔虫的形态学和分子特征分析可为鸡蛔虫的鉴定以及鸡蛔虫病的防控奠定理论基础。

Objective To identify the taxonomy for Ascaridia galli by investigating its morphological and molecular characteristics and phylogenetic analysis.Methods The Ascaridia galli was isolated from the small intestines of chickens collected in Huangshan area,Anhui Province,and observed under light microscope and scanning electron microscope for the morphology.Then genes ITS and COⅠof Ascaridia galli were amplified,cloned and analyzed for homology and phylogeny.Results Morphological observation showed that the Ascaridia galli was milky white after fixing the dead body.The tail was straight for the female,curly for the male.Three lips,measuring equally in size,arose at the head,and 10 pairs of papillae were seen at the tail of male.The length of COⅠand ITS genes were 655 bp and 1034 bp,respectively.Phylogenetic trees based on COⅠand ITS genes revealed that Ascaridia galli isolates from Huangshan area had the highest homology with those from other countries or regions,with COⅠand ITS identity being up to 100%and 99.9%respectively.This nematode Ascaridia galli was clustered in one clade.Conclusion Analysis of the morphological and molecular characteristics for Ascaridia galli can lay a foundation for identification,prevention and control of this species.