Calcium signalling during the cleavage period of zebrafish development

Abstract

Imaging studies, using both luminescent and fluorescent Ca2+-sensitive reporters, have revealed that during the first few meroblastic cleavages of the large embryos of teleosts, localized elevations of intracellular Ca2+accompany positioning, propagation, deepening and apposition of the cleavage furrows. Here, we will review the Ca2+transients reported during the cleavage period in these embryos, with reference mainly to that of the zebrafish (Danio rerio). We will also present the latest findings that support the proposal that Ca2+transients are an essential feature of embryonic cytokinesis. In addition, the potential upstream triggers and downstream targets of the different cytokinetic Ca2+transients will be discussed. Finally, we will present a hypothetical model that summarizes what has been suggested to be the various roles of Ca2+signalling during cytokinesis in teleost embryos.