Event

TODAY'S SEMINAR IS CANCELED

The freshwater cnidarian Hydra is famous for its regenerative capabilities. Hydra can regenerate from small tissue pieces and from cell aggregates following complete dissociation into individual cells. We have recently shown that tissue surface tensions drive cell sorting in Hydra cell aggregates (Cochet-Escartin et al., Biophys. J. 2017). Once sorting is complete or tissue pieces have rounded up, as regeneration proceeds, a hollow bilayer sphere forms, which undergoes osmotically driven shape oscillations. The sphere eventually breaks shape symmetry to form an ellipsoid, defining the future head-foot polarity of the adult polyp. How these mechanical oscillations are linked to shape (sphere à ellipsoid) and biochemical (head - foot) symmetry breaking has been an open question for nearly a decade. Different mechanisms have been proposed in an attempt to link mechanics and signaling, but a definitive answer is still missing. In my talk, I will present our recent work on this question, which provides the missing link between oscillation dynamics and biological events by deciphering the mechanism controlling the regeneration dynamics of Hydra tissue spheres.