Calcium wave pacemakers in eggs

Rémi Dumollard, John Carroll, Geneviève Dupont, Christian Sardet

Research output: Contribution to journalArticleResearchpeer-review

62 Citations (Scopus)

Abstract

During the past 25 years, the characterization of sperm-triggered calcium signals in eggs has progressed from the discovery of a single calcium increase at fertilization in the medaka fish to the observation of repetitive calcium waves initiated by multiple meiotic calcium wave pacemakers in the ascidian. In eggs of all animal species, sperm-triggered inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3] production regulates the vast array of calcium wave patterns observed in the different species. The spatial organization of calcium waves is driven either by the intracellular distribution of the calcium release machinery or by the localized and dynamic production of calcium-releasing second messengers. In the highly polarized egg cell, cortical endoplasmic reticulum (ER)-rich clusters act as pacemaker sites dedicated to the initiation of global calcium waves. The extensive ER network made of interconnected ER-rich domains supports calcium wave propagation throughout the egg. Fertilization triggers two types of calcium wave pacemakers depending on the species: in mice, the pacemaker site in the vegetal cortex of the egg is probably a site that has enhanced sensitivity to Ins(1,4,5)P3; in ascidians, the calcium wave pacemaker may rely on a local source of Ins(1,4,5)P3 production apposed to a cluster of ER in the vegetal cortex.

Original languageEnglish
Pages (from-to)3557-3564
Number of pages8
JournalJournal of Cell Science
Volume115
Issue number18
DOIs
Publication statusPublished - 15 Sep 2002
Externally publishedYes

Keywords

  • Calcium oscillations
  • Calcium wave pacemaker
  • Cortex
  • Egg
  • Endoplasmic reticulum
  • Fertilization
  • Ins(1,4,5)P

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