Abstract
The mammalian egg's extracellular matrix or zona pellucida (ZP) is composed of only a few unique proteins. The proteins, called ZP1–4, polymerize into fibrils that create a porous matrix that supports oogenesis and participates in species-restricted fertilization. ZP genes are expressed only in females during oocyte growth when ZP protein synthesis and secretion is a major metabolic activity. Nascent ZP proteins possess sequence elements responsible for targeting them to the secretory pathway and preventing their polymerization until they are secreted. Each ZP protein has a signature sequence, the ZP domain (ZPD), that is responsible for their polymerization in the extracellular space. ZP2 and ZP3 are receptors recognized by acrosome-reacted and acrosome-intact sperm, respectively. Both sperm-receptors are inactivated following fertilization of eggs by a single sperm.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
