Calcium Requirement for Sperm-Egg Fusion in Mammals

Abstract

Ca2+ is essential for fusion of hamster, guinea pig and human spermatozoa with eggs. In Ca2+ free media, acrosome-reacted spermatozoa attach to the egg plasma membranes, but are unable to fuse with them. Mg2+ can replace Ca2+, although it is less effective. The relative effectiveness of various divalent cations in triggering sperm-egg fusion and some other types of membrane fusions was compared.