Immunoelectophoretic Identification of Jelly Coat Ligands Bound by the Cortical Granule Lectin from Xenopus laevis Eggs

The formation of the fertilization layer in the Xenopus laevis egg fertilization envelope involves a lectin-ligand interaction and establishes a block to polyspermy in the extracellular matrix of the egg. The cortical granule lectin participating in the formation of the fertilization layer has been isolated but its ligand has not. We identified three jelly coat ligands bound by the cortical granule lectin using immunoelectrophoretic analyses. Two antigens were detected with anti-jelly serum and a third was identified using anti-envelope serum. All three antigenic ligands were associated with the innermost jelly coat layer, J₁, and two of the three antigenic ligands contained sulfate. One or more of these jelly coat ligands may function in establishing a block to polyspermy at fertilization in Xenopus laevis .