Fig. 2. In vivo time-lapse recording of shh-GFP expression in the retina. (A-F) Single frames taken from a film recording of shh-GFP expression in the retina, starting at 35 hpf and ending at 46 hpf. Note that the first amacrine cells expressing shh-GFP are already present at 35 hpf, and that the wave of shh-GFP expression in amacrine cells spreads rapidly following the wave in the GCL.