Shown below is a diagram depicting various stages of the acrosome reaction in sea urchin sperm. The acrosome vesicle undergoes exocytosis when the sperm contacts the jelly layer. The enzymes that are released from the acrosome help the sperm penetrate through the jelly layer and vitelline membrane. Actin polymerization causes the eversion of the acrosomal process.
Sea Urchin Sperm Acrosome Reaction
