Fig. 1 Pseudo-color fluorescence images of calcein-loaded spermatozoa. Each image was obtained by averaging five frames (5 ms/frame). The resultant images of brightness maps are displayed in pseudo-color (white is the brightest and black is the faintest) to clarify the detail of photobleached area. The numbers shown above each image indicate the time course after the photobleaching laser pulse was applied (units: ms). The leftmost image was obtained just before photobleaching. The white circle indicates the region where the photobleaching laser pulse was directed. Scale bar, 10 µm.