Fig. 1. Expression of shh in the zebrafish retina. All panels show confocal sections through the retina, with anterior to the top. GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer; ACs, amacrine cells. (A) Whole-mount detection of shh RNA in the retina at 46 hpf. Note expression in the GCL and proximal INL. (B) Expression of shh-GFP (green) and Zn5 (red). Note that shh-GFP and Zn5 are co-expressed in ganglion cells, and that shh-GFP is also expressed by a subset of amacrine cells. (C) High magnification of the retina shown in B. Note that GFP is also present in neurites that contribute to the inner plexiform layer (IPL). (D) Expression of the shh-GFP at 46 hpf (GFP single channel of the image shown in F). Note expression in the GCL, and proximal INL. (E) Isl1 single channel of the image shown in F. Note expression in the GCL and proximal INL, as well as in the distal INL. (F) Retina at 46 hpf, double labeled for Isl1 protein (red) and GFP (green) expressed by the shh-GFP line. (G) High magnification of the GCL double labeled for Isl1 (red) and shh-GFP (green) at 46 hpf. Note that some RGCs express only Isl1 (arrowhead), whereas some RGCs express both Isl1 and shh-GFP (arrow). (H) shh-GFP single channel of the image shown in G. (I) Isl1 single channel of the image shown in G.