基于12S rRNA基因序列的犬弓首蛔虫种系发育关系分析

摘要

本次研究旨在分析河南省不同地区犬弓首蛔虫分离株线粒体12S rRNA部分基因序列(plastiosome 12S rRNA,p12S rRNA)的遗传变异情况.通过PCR技术对犬弓首蛔虫p12S rRNA序列进行扩增并测序,应用ClustalX 2.0程序对序列进行比对,再利用Mega4.0程序进行NJ法绘制种系发育树.结果显示,所获得的18个犬弓首蛔虫分离株p12S rRNA序列长度为497~499 bp.种系发育分析结果显示,所有的犬弓首蛔虫分离株与已知犬弓首蛔虫位于同一分支,与其他蛔虫所属分支相隔较远.犬弓首蛔虫p12S rRNA序列种内相对保守,而种间差异较大,可以作为种间遗传变异研究的标记,从而为犬弓首蛔虫的分类与流行学调查奠定了基础.%The aims of the present study were to analyze sequence variations in the mitochondrial 12S rRNA gene among Toxocara canls isolates from Henan province. The 12S rRNA was amplified from each of Toxocara canls isolates by PCR and analyzed using the ClustalX 2.0. The results showed that the lengths of all the 12S rRNA sequences were 497 - 499 bp. The 12S rRNA sequences of the Henan isolates and reference Toxocara canls available in GenBank were aligned for phylogenetic analysis and found that they all clustered in the same clade. Therefore, 12S rRNA sequence could be used as a genetic marker for population genetic studies of ascarid. The results of the present study provided foundation for further studies of diagnosis and molecular epidemiology of Toxocara canls.