Reproduction Abstracts

Introduction: Mature mouse oocytes, arrested at meiotic metaphase II (MII), are activated by a series of Ca2+ oscillations caused by sperm-specific phospholipase C zeta (PLCz) which has been shown to localize in cytoplasmic vesicles. The substrate for PLCz, phosphatidylinositol 4,5-bisphosphate (PIP2), is also present in cytoplasmic vesicles in MII oocytes. Throughout oocyte maturation there is reported to be a gradual increase in sensitivity to PLCz and ...