Fig. 3. Ca²⁺ dynamics during the rising phase of the initial Ca²⁺ transient at fertilization. The data in A, B and C were obtained from the oocytes for Fig. 1A, 1C and 2B, respectively. Sequential fluorescence images were acquired every 0.4 seconds, normalized by dividing them by the resting image just before each Ca²⁺ increase in a pixel-to-pixel manner, and expressed as pseudocolor images. The zero time in each montage was defined as the time of the first visible Ca²⁺ increase at fertilization.