MAMMALIAN GAMETE FERTILIZATION - SPERM-ZONA PELLUCIDA INTERACTIONS

Association of sperm with the acellular protective envelope of the ooc yte, the zona pellucida, and their penetration is a determinant step i n fertilization process, If is at this stage that species barriers tak e place to prevent cross fertilizations, This association is dependant upon binding of ZP3 oligosaccharides to specific sperm receptors, The ir activation triggers the acrosome reaction via transduction pathways and release of proteolytic enzymes that dissociate the zona pellucida network, Then, secondary binding to zona pellucida components allows sperm to penetrate and cross the zona pellucida barrier, Several sperm surface proteins are putative receptors for zona pellucida partners, Repercussion of these studies on human fertility are discussed.