Related Experiment Videos
Sperm deliver a new second messenger: NAADP.
Grant C Churchill1, John S O'Neill, Roser Masgrau
1Department of Pharmacology, University of Oxford, Mansfield Road, OX1 3QT, Oxford, United Kingdom. grant.churchill@pharm.ox.ac.uk
Current Biology : CB
|January 28, 2003
Summary
Nicotinic acid adenine dinucleotide phosphate (NAADP) is now recognized as a second messenger. Fertilization triggers a significant increase in NAADP, crucial for egg activation and calcium release.
Area of Science:
- Cellular Biology
- Reproductive Biology
- Biochemistry
Background:
- Nicotinic acid adenine dinucleotide phosphate (NAADP) is a potent calcium (Ca2+) mobilizer.
- NAADP's role as a second messenger was unconfirmed due to lack of evidence for stimulus-induced increases.
Purpose of the Study:
- To investigate if NAADP levels increase during physiological events.
- To determine if NAADP functions as a genuine second messenger in fertilization.
Main Methods:
- Quantified NAADP levels during sea urchin egg fertilization.
- Assessed the role of sperm-derived NAADP in egg activation.
- Examined the effect of NAADP desensitization on fertilization-induced events.
Main Results:
- Reported a significant increase in NAADP during sea urchin egg fertilization.
- Demonstrated that sperm contacting egg jelly produces NAADP, which is delivered to the egg.
- Showed that NAADP induces a cortical flash and that this response is blocked by NAADP desensitization.
Conclusions:
- NAADP increase is a key event during fertilization.
- NAADP acts as a genuine second messenger, mediating sperm-egg interactions and egg activation.