From, Laboratoire Physico-Chimie, Institut Curie

Will give a seminar entitled:

Quantitative biology of microbial sexual communication: what do signals signal?

Summary

Cell-cell communication through extracellular diffusible signals controls a myriad of cellular processes. Signals are usually studied as the quantitative triggers that downstream molecular pathways transduce. However, the importance of the physicochemical properties of the signals themselves, and the role of the number and location of signal sources, are understudied yet relevant aspects necessary to explain the evolution and function of such pathways’ architecture. Here I show two examples of pheromone signaling systems where these aspects are crucial: prokaryotic antibiotic-resistance horizontal gene transfer (in the gut bacterium Enterococcus faecalis) and eukaryotic mating (in budding yeast). Specifically, I’ll show that (i) both organisms sense the relative and not absolute number of signal sources—namely the sender to emitter ratio—to adjust their costly mating effort according to their chances of success and (ii) that mating yeast cells sense each other in specific ways, namely, they sense either the proximity or abundance of potential mates, with the physicochemical properties of the pheromone being a crucial player in the process (iii) The development of optogenetic tools to control signal emission in space and time. Finally, I’ll discuss the implications and applications of this research for evolution, synthetic biology, and development.