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.
Keywords: Phylogenetic characterization; RoTat 1.2 VSG; Trypanosoma evansi.