Cell colonies as active fluids: From bacterial biofilms to epithelial tissues

Date

May 20, 2021

Time

4:00 PM - 5:00 PM

Speaker

Ricard Alert

Affiliation

Princeton Center for Theoretical Science Princeton University

Language

en

Main Topic

Biologie

Host

Jan Brugues

Description

Cells in our body move in groups during development, wound healing, and tumor spreading. Bacterial cells also coordinate their motion to aggregate into biofilms, to feed cooperatively, and to form fruiting bodies. Despite the enormous differences between these cell colonies, can we understand their collective behaviors in terms of common physical principles? In this talk, I will propose that the physics of active fluids provides such an organizing principle. To illustrate this point, I will discuss two examples in which cell colonies exploit active-matter physics to change their morphology. First, I will show that the soil bacterium Myxococcus xanthus forms active liquid crystals, in which cells are strongly aligned. I will show that special points known as topological defects, where cell alignment is lost, promote the formation of new cell layers, allowing the colony to develop fruiting bodies in response to starvation. Second, I will show that the transition between two-dimensional epithelial monolayers and three-dimensional cell aggregates can be understood as the wetting transition of an active fluid. Overall, these examples suggest that not only physical concepts can help us understand biological phenomena, but that biology also inspires the new physics of active matter.

Last modified: May 21, 2021, 12:09:42 AM