Information Processing and Ca2+ Signals Around Epithelial Wounds*

For epithelial cells to heal a wound, those cells must first detect the presence of a nearby wound. The earliest signal indicating such a detection is a cytoplasmic influx of Ca2+ ions. For laser-wounds in Drosophila epithelia, this Ca2+ influx is driven by both mechanical and biochemical signals: cellular micro-tears generated by cavitation-induced shear stresses and ligands released from lysed cells that activate their cognate receptors. Such Ca2+ signaling is dynamic, expanding outward from the wound in two stages over the course of seconds to minutes and then devolving into multi-cellular Ca2+ flares that continue for hours. We will discuss the information content of these dynamic Ca2+ signals and correlate the signals seen by individual cells with the degree to which those cells migrate, change shape and proliferate to help heal the wound.