Light-induced cortical excitability reveals programmable shape dynamics in starfish oocytes

Chemo-mechanical waves play a key role in force generation and long-range signal transmission in cells that dynamically change shape, for example, during cell division or morphogenesis. Reconstituting and controlling such chemically controlled cell deformations is a crucial but unsolved challenge for the development of synthetic cells. Here we present an optogenetic method to investigate the mechanism responsible for coordinating surface contraction waves that occur in oocytes of the starfish Patiria miniata during meiotic cell division. Using optogenetic stimuli, we create chemo-mechanical cortical excitations that are decoupled from meiotic cues and drive various shape deformations, ranging from local pinching to surface contraction waves and breakdown of the cell. A quantitative model entailing both chemical and geometry dynamics allows us to predict and explain the variety of mechanical responses to optogenetic stimuli. Finally, we qualitatively map the observed shape dynamics to understand how the versatility of intracellular protein dynamics can give rise to a broad range of mechanical phenotypes. More broadly, our results suggest a route towards real-time control over dynamical deformations in living organisms and can advance the design of synthetic cells and life-like cellular functions. Optogenetically induced chemo-mechanical excitations are used to drive and study shape deformations in starfish oocytes. Understanding and eventually controlling such waves is important for the development of synthetic cells.