Figure 1. I_Cl,Ca evoked by photoreleased InsP₃ is larger in the animal hemisphere, but the threshold for activation is similar in both hemispheres.

Data from a single albino oocyte show peak amplitudes of I_Cl,Ca evoked by photolysis flashes of varying durations, focused as a 50 μm × 50 μm square positioned on the animal (▪) and vegetal (□) hemispheres. Clamp potential was −60 mV.