EFFECT ON FERTILIZATION OF ANTISERUM AGAINST SPERM-BINDING PROTEIN FROM HOMO- AND HETEROLOGOUS SEA URCHIN EGG SURFACES

When jelly-less sea urchin egg is pretreated with antiserum against sperm-binding protein, which composes vitelline membrane, of homologous species, it cannot bind sperm at all and becomes unfertilizable. Heterologous antisera do not inhibit the sperm-binding, but block sperm-penetration. It is suggested that two systems, one relating to sperm-binding and the other to sperm-penetrating, reside in the vitelline membrane and that species specificity of the sperm-binding system plays a primary role in preventing cross fertilization. © 1969.