Dr. Romain Pigeault

I defended my Ph.d in december 2015. During these three years I worked on the evolutionary ecology of the host/mosquito/Plasmodium interaction. More precisely I tried to identify sources of heterogeneity of vectors’ infection.
One of the most important parameters for the transmission of Plasmodium is the rate and intensity of the mosquito infection. However, within a single population, a great heterogeneity of mosquito infection levels is often observed: some mosquitoes are not infected, others are only weakly infected, and yet others have extremely high infection intensities. Identifying the sources of variation responsible for this heterogeneity is essential in order to understand the transmission dynamics of Plasmodium. Certain genetic and environmental parameters have already been identified as having an impact on mosquito infection rates. Nevertheless, many factors remain to be explored. Using an experimental system composed of the avian malaria parasite Plasmodium relictum, its natural vector Culex pipiens and one of its vertebrate host Serinus canaria, I have investigated the effect of several seldom investigated parameters on the infection of mosquitoes (transgenerational immune priming, aging, circadian rhythm, effect of vertebrate host). Although my studies were mainly experimental, I also worked with collaborators in order to go further in my research by combining my empirical approach with their theoretical one.

My current post-doctoral projects in Lausanne is divided in two parts. Firstly, I continue my research on the sources of heterogeneity of vector’s infection but using a natural system: Plasmodium / Mosquitoes / Great tit. For instance, I will study the effect of seasonality on host's infection rate and its impact on parasite transmission. Secondly, I also work on parasite communities. Indeed, in natural populations of birds many "species" of haemosporidian parasite coexist: some are multi-hosts other on the contrary are more specific. Currently, we don’t understand how so many strains of the same "kind" of parasite coexist and the costs associated to this diversity are misunderstood.