Fig. 3. Concentration-response study of PMA-induced secretion of cortical granule lectin. Single oocytes were incubated in increasing concentrations of PMA, as indicated. After 1 hour, the fluid surrounding each oocyte was collected for analysis by SDS-polyacrylamide gel and Coomassie staining. The results show the smear of cgl between 35 and 50 kDa (see also Fig. 1) for two separate sets of oocytes. Pilot experiments revealed that secretion of cgl induced by 10 nM PMA was complete within 1 hour.