The acrosome reaction in boar spermatozoa.

In order to gain more insight into the molecular alterations of the acrosome, boar spermatozoa were incubated in a calcium-containing medium in the presence of the ionophore A23187. The time-course of the acrosome reaction was assessed by phase-contrast microscopy. Different stages of the acrosome reaction were studied by immunoelectron microscopy using a specific antibody directed against the complete outer acrosomal membrane. The introduction of monoclonal antibodies generated by immunization of Balb/c mice with the isolated outer acrosomal membrane permitted a study of the topography of distinct membrane proteins during the acrosome reaction. The exposure of activation of a fucose-binding protein important for sperm--zona attachment was studied using neo-glycoproteins labelled with colloidal gold for transmission electron microscopy.