Role of calcium signals in early development.

The mammalian egg appears to transduce the duration, amplitude, and temporal presentation of the increase in the intracellular calcium concentration ([Ca(2+)](i)) upon fertilization. These Ca(2+) parameters have important short-term effects on the initiation and completion of early events of egg activation, as well as much later consequences for the extent of peri-implantation development. Recent studies have begun to shed light on how the egg quantitatively interprets the Ca(2+) signal (e.g., by summation of individual Ca(2+) rises) and the mechanisms by which down-stream Ca(2+) effectors, such as Ca(2+)/Calmodulin (CaM)-dependent protein kinase II (CaMKII), utilize this ionic signal to promote biological events that initiate development.