Fly fishing for collective cell migration

The collective migration of cells is essential for organogenesis. It requires the establishment of spatial information within the cellular group and a mechanism that controls the onset of cell movement and migratory arrest. In this review I will use two examples of collective cell migration, from Drosophila and the zebrafish, to discuss how genetic analyses have helped to unravel some basic aspects of collective cell migration. Following, I will suggest some general experimental approaches to further advance our understanding of the mechanisms that control the migration of cellular collectives.