A MODEL FOR SPERM-EGG BINDING AND FUSION BASED ON ADAMS AND INTEGRINS

Once a sperm meets an egg, several events must occur in order for fert ilization to proceed. Sperm must bind to the zona pellucida, undergo t he acrosome reaction, penetrate the zona pellucida and then bind to an d fuse with the egg plasma membrane. Shortly thereafter, the egg must be activated for zygotic development. This review focuses on mammalian sperm-egg plasma membrane binding and fusion, and in particular on th e roles of two families of cell-adhesion molecules, ADAMs and integrin s, in this important union.