Acrosome Reaction in Marine Animals: Gateway to Sperm Fusion with the Egg

摘要

Acrosome Reaction (AR) is of fundamental importance in the fertilization of egg by spermatozoon. In external fertilizers like starfish, sea urchin and ascidian egg and sperm are spawned simultaneously into the surrounding water. Upon swimming, sperm must obtain motility and then they must swim towards or respond to the egg in some way. Components from the jelly layer of the egg influence ion permeability changes in sperm that regulate chemotaxis and the AR prior to fertilization. The acrosomal process is surrounded by a new membrane that allows sperm to interact with the egg?s vitteline layer and, subsequently, to fuse with the egg plasma membrane. This review summarizes the mechanisms and signal transduction pathways involved in AR.