CMMB 403 Lecture Notes - Lecture 13: Acrosome Reaction, Zona Pellucida, Golgi Apparatus
9 Oct 2018
School
Course
Professor
Document Summary
Concept of the day: five key steps on the pathway to fertilization in mammals. The physiological changes the sperm must undergo within the female reproductive system to become competent to fertilize an egg. Sperm has to spend a minimum of 6 hours in the female reproductive tract before it can fertilize an egg. Binding of sperm to the zona pellucida (zp) Happens through a specific zp protein (zp2 in humans, zp3 in mice) Zp is like an extracellular matrix of the egg, and zp proteins are glycoproteins. This is a reaction in which the contents of the acrosomal vesicle are expelled through exocytosis allowing sperm penetration through the zp. Fusion of the membranes allows sperm dna to enter the egg. Out of approximately 300 million sperm that are released in ejaculate, only about 200 reach the egg, and out of that, only one (normally) fertilize the egg.
