Localized Calcium Transients Accompany Furrow Positioning, Propagation, and Deepening during the Early Cleavage Period of Zebrafish Embryos☆☆☆

摘要: Abstract Through the injection of f -aequorin (a calcium-specific luminescent reporter) and use an imaging photon detector, we see a distinct localized elevation intracellular calcium that accompanies appearance first furrow arc at blastodisc surface: positioning signal. As leading edges progress outward toward margins blastodisc, they are accompanied by two subsurface slow waves moving about 0.2 μm/s: propagation these wave fronts approach edge another signal arises in central region where originally appeared. Like signal, it extends to but this case also moves downward, accompanying deepening process separates daughter cells: Both progressions move around 0.1 μm/s. The begins diminish from center outward, returning precleavage resting levels on completion cytokinesis. signaling sequence is repeated during second cell division cycle. These transients do not require external can be dissipated after have begun introducing shuttle buffers, resulting delocalization regression. They occur parthenogenetically activated eggs which, attenuated form, accompany abortive cleavages.