Molekularbiologie der Gametenvereinigung

Contact between gametes takes place on a molecular basis via receptors on the surface of the egg coat. The functional part of this receptor glycoprotein is limited to the O-glycosidic-linked carbohydrate side chains, and a polypeptide chain of it may induce an acrosomal reaction on the sperm head, thereby inducing penetration of the sperm into the egg cell. Another function of sperm receptors is to block polyspermy, probably due to modification by limited proteolysis of the receptor glycoprotein. Fertilization is likely to be inhibited by steric hindrance of the receptor due to antibodies specific for glycoproteins of the egg coat. The study of gamete interactions on a molecular basis may serve as a model for intercellular recognition in general.