Background

Numerous phylogenetic markers have been tested over a period of time for delineating evolutionary history of haemoflagellate—Trypanosoma evansi.

Purpose

To find out the associative genetic diversity, within the various isolates of T. evansi across the globe, based on RoTat 1.2 VSG gene.

Methods

A total of 5 equine isolates of T. evansi from Northern India were characterized. PCR products were sequenced and sequences were compared with available sequences across India and world. Phylogenetic tree was constructed based on maximum parsimony (MP) method with the tree-bisection-regrafting (TBR) algorithm.

Results

Indian isolates formed multiple clades with two haplotypes. The present isolates showed 99.49–100.00% nucleotide homology within themselves. On broader line, Indian isolates were found to be closer to Egyptian isolates than the African counterparts. Few of the Indian isolates showed marked resemblance with a particular Egyptian isolate than with their Indian counter parts. Another remarkable finding is the close association of equine isolates from India with other equine isolates and their clear divergence from isolates of T. evansi affecting other hosts from India and abroad.

Conclusion

Vast genetic divergence was seen between the isolates suggesting of multiple distinct lineages of T. evansi amongst the Indian livestock. Interestingly, variations in sequences were seen based on the host range of isolates. The findings are very important from molecular evolutionary point of view.

中文翻译：

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不同伊氏锥虫分离株中 RoTat 1.2 VSG 的关联遗传多样性。

背景

许多系统发育标记已经在一段时间内进行了测试，以描绘血鞭毛虫的进化历史 -伊文氏锥虫。

目的

为了找出关联的遗传多样性，各株内T.伊氏在全球范围内，基于ROTAT 1.2 VSG基因。

方法

对来自印度北部的 5 种马科分离株T. evansi进行了表征。对 PCR 产物进行测序，并将序列与印度和世界各地的可用序列进行比较。系统发育树是基于最大简约（MP）方法和树二分再嫁接（TBR）算法构建的。

结果

印度分离株形成了具有两个单倍型的多个进化枝。目前的分离株显示出 99.49-100.00% 的核苷酸同源性。在更广泛的范围内，发现印度分离株比非洲分离株更接近埃及分离株。很少有印度分离株与特定的埃及分离株表现出明显的相似性，而不是与它们的印度对应物相似。另一个显着的发现是来自印度的马分离物与其他马分离物的密切关联，并且它们与影响来自印度和国外的其他宿主的伊万斯木虱分离物明显不同。

结论

在分离株之间观察到巨大的遗传差异，这表明印度牲畜中存在多个不同的伊万斯木虱谱系。有趣的是，根据分离株的宿主范围可以看到序列的变化。从分子进化的角度来看，这些发现非常重要。