Int. J. Dev. Biol. 52: 571 - 584 (2008)

https://doi.org/10.1387/ijdb.072560ls

Vol 52, Issue 5-6

Special Issue: Fertilization

The role of the actin cytoskeleton in calcium signaling in starfish oocytes

Published: 1 July 2008

Luigia Santella*, Agostina Puppo and Jong Tai Chun

Cell Signaling Laboratory, Stazione Zoologica Anton Dohrn, Napoli, Italy

Abstract

Ca²⁺ is the most universal second messenger in cells from the very first moment of fertilization. In all animal species, fertilized eggs exhibit massive mobilization of intracellular Ca²⁺ to orchestrate the initial events of development. Echinoderm eggs have been an excellent model system for studying fertilization and the cell cycle due to their large size and abundance. In preparation for fertilization, the cell cycle-arrested oocytes must undergo meiotic maturation. Studies of starfish oocytes have shown that Ca²⁺ signaling is intimately involved in this process. Our knowledge of the molecular mechanism of meiotic maturation and fertilization has expanded greatly in the past two decades due to the discovery of cell cycle-related kinases and Ca²⁺-mobilizing second messengers. However, the molecular details of their actions await elucidation of other cellular elements that assist in the creation and transduction of Ca²⁺ signals. In this regard, the actin cytoskeleton, the receptors for second messengers and the Ca²⁺-binding proteins also require more attention. This article reviews the physiological significance and the mechanism of intracellular Ca2+ mobilization in starfish oocytes during maturation and fertilization.

Keywords

cell activation, sperm-egg interaction, meiosis, germinal vesicle, cyclic ADP ribose, NAADP