Membrane wounding triggers ATP release and dysferlin-mediated intercellular calcium signaling.

Dysferlin is a Ca(2+)-binding protein found in many different cell types. It is required for membrane wound repair in muscle, but it is not known whether it has the same function in other cells. Here we report the activation of an intercellular signaling pathway in sea urchin embryos by membrane wounding that evokes Ca(2+) spikes in neighboring cells.

Two independent forms of endocytosis maintain embryonic cell surface homeostasis during early development.

Eukaryotic cells have multiple forms of endocytosis which maintain cell surface homeostasis. One explanation for this apparent redundancy is to allow independent retrieval of surface membranes derived from different types of vesicles. Consistent with this hypothesis we find that sea urchin eggs have at least two types of compensatory endocytosis.