reproductive process premature acrosome loss spontaneous acrosome loss dph GO:0061948 If the release of the acrosome content when the sperm reaches to the zona pellucida, consider using acrosome reaction. biological_process 2017-10-25T17:46:55Z The discharge, by sperm, of a single, anterior secretory granule before the sperm reaches 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.