Phylogenomic Reconstruction Supports Supercontinent Origins forLeishmania

Abstract

Leishmania, a genus of parasites transmitted to human hosts and mammalian/reptilian reservoirs by an insect vector, is the causative agent of the human disease complex leishmaniasis. The evolutionary relationships within the genus Leishmania and its origins are the source of ongoing debate, reflected in conflicting phylogenetic and biogeographic reconstructions. This study employs a recently described bioinformatics method, SISRS, to identify over 200,000 informative sites across the genome from newly sequenced and publicly available Leishmania data. This dataset is used to reconstruct the evolutionary relationships of this genus. Additionally, we constructed a large multi-gene dataset; we used this dataset to reconstruct the phylogeny and estimate divergence dates for species. We conclude that the genus Leishmania evolved at least 90-100 million years ago. Our results support the hypothesis that Leishmania clades separated prior to, and during, the breakup of Gondwana. Additionally, we confirm that reptile-infecting Leishmania are derived from mammalian forms, and that the species that infect porcupines and sloths form a clade long separated from other species. We also firmly place the guinea-pig infecting species, L. enrietti, the globally dispersed L. siamensis, and the newly identified Australia species from kangaroos as sibling species whose distribution arises from the ancient connection between Australia, Antarctica, and South America.

Study of Leishmaniasis Disease: A Systematic Review

“…Sand fly is considered the host for the leishmaniasis parasite and this insect is seasonal in its appearance in temperate regions of the world, adults appear only in the summer, that is, the breeding season is confined to the summer season in the tropics, and some species seem almost constant throughout the year, but in other species there may be significant changes to an extent that is considered for the group of adults, especially in the dry and wet climates (Harkins et al, 2016).…”