Fig. 3. Injection of excess cyclin-GFP leads to long-lasting Ca²⁺ oscillations. Cyclin-GFP fusion protein was microinjected into eggs prior to monitoring Ca²⁺ at fertilization. Cyclin-injected eggs produced long-lasting Ca²⁺ oscillations at fertilization (A). The schematic diagrams show the state of the eggs under bright-field observation. Cyclin-injected eggs showed no sign of second polar bodies or pronuclei (A). The duration of Ca²⁺ signalling in cyclin-injected eggs (n=15) is significantly longer than in controls (n=18) (B). Data show the mean±s.d.