ProjetÉtude de la dynamique évolutive des cyanobactéries et de leurs phages en milieux aquatiques
Microbial communities have the capacity to shape the biotic and abiotic properties of their surrounding environment, which in turn feeds back to shape the microbial community.Therefore, in order to understand any microbial community's ecology and predict how these communities and their respective ecosystems will respond to environmental changes, it is essential (i) to identify the different ecologically distinct populations and subpopulations that compose it, (ii) to determine their mutual interactions and how they evolve in response to biotic and abiotic environmental changes. In this context, my primary research interests are to study microbial communities in their natural environments by investigating how they respond to changing selective pressures over time. Their responses can take different forms: (i) ecological responses, consisting of changes in relative abundance of different species or populations within a community; (ii) evolutionary responses, consisting of changes in alleles frequencies within a population, and (iii) physiological responses, such as changes in gene expression patterns. For this work, I will focus on two cyanobacterial populations, Microcystis and Dolichospermum, and their associated viruses (phages). Microcystis and Dolichospermum are both toxic, bloom-forming cyanobacteria found in eutrophic freshwaters over the world and cyanomyovirus infect cyanobacteria and belongs to the largest virus family in marine or freshwater: the Myoviridae.