BIO380H5 Lecture Notes - Lecture 9: Acrosome, Zona Pellucida, Exocytosis
Document Summary
Human zona pellucida is made of 4 major glycoproteins. Zp1 and zp4 are important for structural integrity of the zona pellucida. Non-growing oocyte = possibly a primary oocyte that has completed mitosis (and is paused in prophase i?) Zp protein genes are only expressed during the time period the zona pellucida is forming. Up to 50 enzymes in the sperm acrosome have been discovered, there may be many more yet to be identified. By the time fertilization happens, cumulus oophorus drops off. Prior to sperm contacting the egg, it contacts the corona radiata. But what triggers the acrosome reaction is the contact with the zona pellucida. When the sperm touches the membrane of the egg, most of the acrosome has already vesiculated so what touches are the sperm membrane and the egg s cell membrane. Sperm has to be able to contact the zp and to stay attached to it. Galtase reaction in sperm is different from its normal reaction.
