NON-PROPAGATED CORTICAL REACTIONS INDUCED BY THE DIVALENT IONOPHORE A23187 IN EGGS OF THE SEA-URCHIN, LYTECHINUS-VARIEGATUS

The divalent ionophore A23187 can induce a non-propagated discharge of cortical granules in sea urchin eggs resulting in the elevation of partial fertilization membranes. This occurs when unfertilized eggs (1) partially overlap the margin of a solid film of the ionophore; (2) touch a Sephadex bead previously infiltrated with the ionophore; or (3) are exposed to solutions of ionophore for short periods (15-30 sec). These results demonstrate that the release of cortical granules does not automatically induce the discharge of neighboring granules. © 1979.