Joseph d’Alessandro
Institut Jacques Monod, CNRS/Université Paris Cité, équipe Adhésion Cellulaire et Mécanique

“From collective cell migration to local cell-cell interactions and back: symmetry matters”

The coordinated motion of cells underlies a broad variety of biological events in multicellular organisms, from embryonic development and throughout adult life. This phenomenon relies on the motility of individual cells, itself powered by the cytoskeleton, a subcellular, dynamic and spatially structured assembly of proteins. As such, cells can be seen as self-propelled polar particles interacting together, and we can reasonably hypothesize that local cell-cell interactions acting both on cells’ positions and polarities determine the large-scale properties of group motion. However, the properties of such interactions, their biological support and their consequences at the group level remain elusive. In this talk, I will put in perspective our recent works on epithelial cells cultured on micropatterned environments. I will show how they point to the existence of such local interactions affecting the polarity of individual cells and what minimal picture of those interactions one can draw. In particular, our data help interpreting the apparent paradox that aligning and anti-aligning interactions may coexist and even that either one may dominate the other depending on the context.