Viral evolutionary analyses as a magnifying glass on parasite population dynamics

Rapidly evolving pathogens may be used to study the contemporary
population structure and recent demographic history of their
genetically uniform hosts. Because bacterial/viral evolution can
manifest itself over months or years, bacteria/viruses may provide
insights into host evolution that were not apparent from host genetic
data, and that would be impossible to obtain by other means. Here,
we want to apply the concept of “viruses as genetic tags of their host”
and use - for the first time - evolutionary timescales of a virus, here
the Leishmaniavirus, to gain insights into the population dynamics of
a vector-borne pathogen, here the Leishmania parasite (here
considered as the host of the virus). First, we will examine the
geographic distribution of Leishmaniaviruses in South-America by
retrospectively screening and sequencing 506 Leishmania isolates.
Second, we will reconcile the spatiotemporal scale of the coevolutionary
history between both species. Finally, we will use
phylogeographic and phylodynamic tools to model the spatiotemporal
evolution of Leishmaniaviruses in South-America. By
aligning evolutionary histories of the two symbiotic species, our
unique approach will provide major insights into the specific
bioclimatic, spatial and environmental factors that have influenced
the spread of a zoonotic disease throughout history, and more
recently in response to climate change and deforestation.