Nonacrosomal

When this occurs are new nonacrosomal antigens becoming involved?

The acrosome reaction is a prerequisite for fusion between ova and spermatozoa plasma membranes, and zona free ova cannot undergo fusion with nonacrosomal activated sperm even though attachment to the membrane surface occurs (Fig. 8-3).

Even in spermatids of the cat and of man in which Burgos and Fawcett (1955) and Fawcett (1958) have shown that a fibrous perforatorium does not occur, it can nevertheless be seen in thin sections (Fawcett, 1958; Horstmann, 1961) that the homologous sites contain at least small amounts of nonacrosomal substance.