Ca2+ signalling during fertilization of echinoderm eggs

The Ca2+ rise at fertilization of echinoderm eggs is initiated by a process requiring the sequential activation of a Src family kinase, phospholipase C gamma, and the inositol trisphosphate receptor/channel in the endoplasmic reticulum. The consequences of the Ca2+ rise include exocytosis of cortica l granules which establishes a block to polyspermy and inactivation of MAP kinase, which functions in linking the Ca2+ rise lo the reinitiation of the cell cycle.