Biological process

The discharge, by sperm, of a single, anterior secretory granule following the sperm's attachment to the zona pellucida of the oocyte. The process begins with the fusion of the outer acrosomal membrane with the sperm plasma membrane and ends with the exocytosis of the acrosomal contents into the zona pellucida.

If the release of the acrosome content occurs before the sperm reaches the zona pellucida, consider using premature acrosome loss.