Abstract
It is well known that Ca 2+ fluxes occur before the activation of the fertilized ovum; however, little is known about the events preceding Ca 2+ mobilization. Kuo et al . show that nitric oxide (NO) is required for egg activation. Fluorescence assays indicated that NO synthase is present in sperm at the head and concentrated at the acrosome; however, NO production depended on the acrosome reaction. Eggs injected with a NO donor, S -nitrosoacetylpenicillamine (SNAP), or with recombinant NO synthase in conjunction with calmodulin became activated, whereas preinjection of eggs with oxyhemoglobin (oxyHb), a NO scavenger, prevented egg activation. Addition of ionomycin to oxyHb rescued the ability of eggs to become activated. Similarly, injecting SNAP into eggs elicited a strong wave of Ca 2+ release; this was blocked by preinjection with oxyHb, suggesting that NO production is necessary and sufficient before the elicitation of Ca 2+ fluxing and egg activation. Kuo, R.C., Baxter, G.T., Thompson, S.H., Stricker, S.A., Patton, C., Bonaventura, J., and Epel, D. (2000) NO is necessary and sufficient for egg activation at fertilization. Nature 406 : 633-636. [Online Journal]
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.
