A wave of free cytosolic calcium traverses zebrafish eggs on activation
|Authors||Lee, Karen W.
Webb, Sarah E.
Miller, Andrew L.
|Source||Developmental biology , v.214, (1), 1999, October, p. 168-180|
|Summary||The activation process in a variety of deuterostome and protostome eggs is accompanied by cytosolic calcium transients that usually take the form of either a single or multiple propagating waves. Here we report that the eggs of zebrafish (Danio rerio) are no exception in that they generate a single activation wave that traverses the egg at a velocity of around 9 µm/s. There appears, however, to be no difference between the calcium-mediated activation response of eggs with regards to the presence or absence of sperm in the spawning medium. This leads us to suggest that these eggs are normally activated when they come in contact with their spawning medium, and then subsequently fertilized. The aspermic wave is initiated at the animal pole in the region of the micropyle, appears to propagate mainly through the yolk-free egg cortex, then terminates at the vegetal pole. As neither sperm nor external calcium are required for the initiation (or propagation) of the activation wave, this suggests that an alternative wave-trigger must be involved.|
|Rights||Developmental biology © copyright (1999) Academic Press. The Journal's web site is located at http://www.sciencedirect.com/|
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