What Happens During the Latent Period at Fertilization
A period of several seconds to half a minute can elapse between the initial interaction of the fertilizing sperm with the egg and the initiation of the calcium wave that causes global egg activation. It has been called the latent period. We discuss experiments that have shed light on what is happening during the latent period. We suggest that the latent period reflects the transfer of an activating messenger from the sperm to the egg through a labile fusion pore. The latent period ends when the messenger triggers the increase in cytoplasmic calcium that consolidates the labile fusion state and then sweeps across the egg, activating it.
KeywordsLatent Period Uranyl Nitrate Calcium Wave Inositol Trisphosphate Fusion Pore
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