Pathogen emergence and host adaptation

Résumé

  A host radiation or host transfer may come with adaptive evolutionary changes in the pathogens associated with the adaptation to the new environment. Identification of the genomic regions in the parasite genome underlying the differences between host-specific lineages may provide information about the molecular basis for species-specific adaptation.Here, I will focus on host adaptation of primate pathogens of the genus Plasmodium. Plasmodium falciparum, the most common and deadliest human malaria parasite, is derived from a group of parasites infecting African great apes and known as the Laverania subgenus. There are at least in this subgenus 7 species naturally infecting chimpanzees (3 species), gorillas (3 species) or human (P. falciparum only) with a high specificity. We looked for signatures of interspecific gene flow, selection and convergent evolution to investigate host adaptation of Laverania species. We found evidence that interspecific gene flow and convergent evolution occurred during the evolution of these species and might have been important for host adaptation in this subgenus.