Coraline Bichet PhD thesis

Avian malaria evolutionary ecology: hosts immunity and evolution of virulence

Funding: French research minister grant

Supervisor: Gabriele Sorci

Beginned in october 2009

Defended 18 december 2012

 

Abstract

Host-parasite interactions are one of the main topics in evolutionary sciences. This complex coevolution depends on several trade-offs and can be influenced by environmental factors. Here, we propose to study host-parasite interactions with a multi-level approach, using experimental and natural population studies, focusing on avian malaria parasites. First, we studied the effect of host characteristics, and more precisely the immune system. The immune system confers benefits in terms of protection against the parasite, but can also generated immunopathological costs. Life history traits, like age or social status, appear to modify parasitemia but not prevalence. In a second part, we evaluated the effect of environmental factors on host-parasite interactions. We found that temperature and heavy metal contamination had an effect on population prevalence, but not on host parasitemia. We also showed the direct parasite influence on host population genetic structure, and more precisely on MHC genes.

 

Keywords

avian malaria, domestic canaries, house sparrow, major histocompatibility complex, immune system, life history traits, environment, mate choice.