Phospholipase C zeta undergoes dynamic changes in its pattern of localization in sperm during capacitation and the acrosome reaction

Objective: To evaluate the localization of phospholipase C zeta (PLC zeta) in non-capacitated, capacitated, and ionophore-treated sperm. Design: Phospholipase C zeta was cloned from the hamster, an important model organism for studying fertilization. Next, we used hamster and mouse models to investigate the localization of PLC zeta in non-capacitated and capacitated sperm and in sperm treated with ionophore to induce the acrosome reaction. Setting: University laboratory. Animal(s): Male mice and hamsters, 4-6 weeks old. Intervention(S): None. Main Outcome Measure(s): Phospholipase C zeta localization in non-capacitated, capacitated, and ionophore-treated sperm. Result(s): Full-length hamster PLC zeta complementary DNA is 1953 base pairs in size, encoding an open reading frame of 651 amino acids, sharing 85% amino acid similarity with the mouse. Phospholipase C zeta was localized in acrosomal and post-acrosomal regions of sperm. The post-acrosomal localization, which became more evident after capacitation and was maintained after ionophore treatment, is in line with PLC zeta being the endogenous agent of egg activation. However, the acrosomal PLC zeta population, which was lost after ionophore treatment, suggests that PLC zeta could have other functions besides egg activation. Conclusion(s): Phospholipase C zeta is localized to acrosomal and post-acrosomal regions and undergoes dynamic changes during capacitation and the acrosome reaction, indicating a potential role regulating not only egg activation but other sperm functions. (Fertil Steril (R) 2009;91:2230-42. (C)2009 by American Society for Reproductive Medicine.)