Egg-to-embryo transition is driven by differential responses to Ca(2+) oscillation number

Dev Biol. 2002 Oct 15;250(2):280-91.


Ca(2+) oscillations and signaling represent a basic mechanism for controlling many cellular events. Activation of mouse eggs entrains a temporal series of Ca(2+)-dependent events that include cortical granule exocytosis, cell cycle resumption with concomitant decreases in MPF and MAP kinase activities, and recruitment of maternal mRNAs. The outcome is a switch in cellular differentiation, i.e., the conversion of the egg into the zygote. By activating mouse eggs with experimentally controlled and precisely defined Ca(2+) transients, we demonstrate that each of these events is initiated by a different number of Ca(2+) transients, while their completion requires a greater number of Ca(2+) transients than for their initiation. This combination of differential responses to the number of Ca(2+) transients provides strong evidence that a single Ca(2+) transient-driven signaling system can initiate and drive a cell into a new developmental pathway, as well as can account for the temporal sequence of cellular changes associated with early development.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium Signaling / physiology*
  • Cell Cycle
  • Electric Stimulation
  • Female
  • Fertilization / physiology
  • Male
  • Maturation-Promoting Factor / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred CBA
  • Mitogen-Activated Protein Kinases / metabolism
  • Models, Biological
  • Oocytes / metabolism*
  • Zygote / metabolism*


  • Maturation-Promoting Factor
  • Mitogen-Activated Protein Kinases