Phage-E. coli system to study the evolution of host-pathogen interactions
Similar to other viruses, phage has to recognize the host cell, insert its genetic material, exploit the molecular machinery of the host to replicate new viable viruses, and finally lyse the cell to infect new hosts. Any of these steps requires host-virus interactions and is thus under strong selective pressure in both the virus and the host.
Guided by experiments, we build quantitative models of ecoliphage evolution in explicitly spatial settings to identify the key ingredients that shape evolution of phage and its host in natural spatially structured environments (soil, surface of plants, the gut, etc...). The gained insight allows us to better understand how viruses spread and evolve.
Phage clearing on a bacterial lawn after two days at 4C (diffusion and infection) and three hours at 37C (cell lysis).
Spatial population models to understand growth regulation and differentiation
The genealogical tree obtained using the Eden model for colony growth starting from a single cell (star) exhibits few long lineages, in stark contrast to a well-mixed scenario.
A bacterial colony and the stem cell pool in a multi-cellular organism may seem to have little in common. Yet, at a very basic level, they both stem from a single initial cell and asexually divide in space. They are both subject to mutations, which can alter their proliferation rates, and genetic drift, which removes diversity. They both respond to chemical and mechanical cues created by the surrounding cells and the environment.