Parasite evolution through the lens of a unique microbial alliance; Evolutie van parasieten doorheen de lens van een unieke microbiële alliantie

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 1, to gain insights into the population dynamics of a vector-borne pathogen, here Leishmania braziliensis. First, we will examine the geographic distribution of Leishmaniaviruses in South America by retrospectively screening and sequencing 503 Leishmania isolates. Second, we will reconcile the spatiotemporal scale of the co-evolutionary history between both species. Finally, we will apply population and landscape genomic approaches to uncover the population structure of L. braziliensis and make use of phylogeographic and phylodynamic tools to model the spatio-temporal 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.