Male infertility-linked point mutation disrupts the Ca2+ oscillation-inducing and PIP2 hydrolysis activity of sperm PLCζ

A male infertility-linked human PLC zeta (phospholipase C zeta) mutation introduced into mouse PLC zeta completely abolishes both in vitro PIP2 (phosphatidylinositol 4,5-bisphosphate) hydrolysis activity and the ability to trigger in vivo Ca2+ oscillations in mouse eggs. Wild-type PLC zeta initiated a normal pattern of Ca2+ oscillations in eggs in the presence of 10-fold higher mutant PLC zeta, suggesting that infertility is not mediated by a dominant-negative mechanism.