Fig. 8

The distribution of IP₃Rs in the zebrafish blastoderm from 2.25 hpf to 4.25 hpf. (A–E) Single confocal images taken though the blastoderm of embryos, which were fixed at the stage indicated in the upper right corner and then labeled by immunohistochemistry with the 18A10 monoclonal antibody. The color scale represents the relative level of IP₃R labeling with red being the highest and black, the lowest level. In panel A, the white dashed line illustrates the boundary between the superficial epithelium and the underlying deep cells (DC) and the blue, pink and black squares represent the location of three 20 x 20-pixel sampling regions that were used to quantify the intensity of fluorescence in the SECs and in the deep cells at depths of 40 μm and 80 μm from the superficial epithelium. Panel F is a schematic to show the location on the blastoderm (in the red square) of the confocal images (panels A–E) acquired. (G) Histogram showing the relative level of fluorescence that was detected in the three 20 x 20-pixel size sampling regions (illustrated in panel A), at each time point. From 2.75–4.25 hpf, the fluorescent signals detected in the SECs were significantly higher (at p < 0.01, as indicated by “*”) than those detected in the deep cells. Scale bar = 20 μm.