Extensive work on cell division has been performed to understand the properties of the dividing cells. However, it has only recently emerged that neighbouring cells take an active part in each division. Here we discover, from a combination of fly genetics, live-imaging and modelling, a new biophysical mechanism that allows mechanical forces to be sensed and transmitted from the dividing cell to its neighbours. This allows epithelial tissues to maintain their required properties (cohesiveness, polarity) while being dynamic and actively proliferating.

Photo: 3D reconstruction of a dividing cell (red) pulling on its neighbour (green).