Toggle Main Menu Toggle Search

Open Access padlockePrints

Mammalian egg activation: From Ca2+ spiking to cell cycle progression

Lookup NU author(s): Professor Keith Jones


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Mammalian eggs arrest at metaphase of the second meiotic division (MetII). Sperm break this arrest by inducing a series of Ca2+ spikes that last for several hours. During this time cell cycle resumption is induced, sister chromatids undergo anaphase and the second polar body is extruded. This is followed by decondensation of the chromatin and the formation of pronuclei. Ca2+ spiking is both the necessary and solely sufficient sperm signal to induce full egg activation. How MetII arrest is established, how the Ca2+ spiking is induced and how the signal is transduced into cell cycle resumption are the topics of this review. Although the roles of most components of the signal transduction pathway remain to be fully investigated, here I present a model in which a sperm-specific phospholipase C (PLCζ) generates Ca2+ spikes to activate calmodulin-dependent protein kinase II and so switch on the Anaphase-Promoting Complex/Cyclosome (APC/C). APC/C activation leads to securin and cyclin B1 degradation and in so doing allows sister chromatids to be segregated and to decondense. © 2005 Society for Reproduction and Fertility.

Publication metadata

Author(s): Jones KT

Publication type: Review

Publication status: Published

Journal: Reproduction

Year: 2005

Volume: 130

Issue: 6

Pages: 813-823

ISSN (print): 1470-1626

ISSN (electronic): 1741-7899


DOI: 10.1530/rep.1.00710

PubMed id: 16322541