Abstract |
Following fusion of sperm and egg, the contents of cortical granules (CG), a kind of special organelle in the egg, release into the perivitelline space (cortical reaction), causing the zona pellucida to become refractory to sperm binding and penetration ( zona reaction). Accumulating evidence demonstrates that mammalian cortical reaction is probably mediated by activation of the inositol phosphate (PIP(2)) cascade. The sperm-egg fusion, mediated by GTP-binding protein ( G-protein), may elicit the generation of two second messengers, inositol 1,4,5 triphosphate (IP(3)) and diacylglycerol (DAG). The former induces Ca(2+) release from intracellular stores and the latter activates protein kinase C (PKC), leading to CG exocytosis. Calmodulin-dependent kinase II ( CaMKII) may act as a switch in the transduction of the calcium signal. The CG exudates cause zona sperm receptor modification and zona hardening, and thus block polyspermic penetration. Oolemma modification after sperm-egg fusion and formation of CG envelope following cortical reaction also contribute to polyspermy block.
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Authors | Qing-Yuan Sun |
Journal | Microscopy research and technique
(Microsc Res Tech)
Vol. 61
Issue 4
Pg. 342-8
(Jul 01 2003)
ISSN: 1059-910X [Print] United States |
PMID | 12811739
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)
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Copyright | Copyright 2003 Wiley-Liss, Inc. |
Chemical References |
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Topics |
- Animals
- Cats
- Cattle
- Cytoplasmic Granules
(physiology)
- Exocytosis
- Female
- Fertilization
(physiology)
- Guinea Pigs
- Humans
- Inositol Phosphates
(metabolism)
- Male
- Mice
- Oocytes
(physiology)
- Ovum
(physiology)
- Rabbits
- Rats
- Signal Transduction
- Sperm-Ovum Interactions
- Swine
- Zona Pellucida
(physiology)
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