Collective cell migrations: guiding groups of cells.

Cell migration is a critical process during embryogenesis, defective migration underlying numerous developmental disorders. It is also crucial during adult life, where it ensures wound healing and circulation of immune cells. Thanks to decades of in vitro analyses, we now have a fairly good understanding of how a single cell migrates on its substrate. In vivo however, most cells do not migrate as individual cells, but as part of larger groups of cells. These are called collective migrations, since in these groups, the migration of one cell is dependent on the migration of its neighbors. The cellular and molecular bases of these collective processes are just starting to be unraveled. In this talk, using instances from a few model systems, I will illustrate our current understanding of how guidance of these cell groups is achieved, highlighting how these groups organize and the emerging properties that arise from collectivity.