Fig. 7. Hdac1 antagonizes Wnt signaling to promote cell-cycle exit of retinal cells. (A,B) GFP expression in TOPdGFP transgenic retinas treated with DMSO (A) and 400 nM TSA from 10 hpf (B). Arrowhead indicates GFP expression in the CMZ. GFP expression level increases in the TSA-treated TOPdGFP transgenic retina. Broken white lines show the interface between the brain and retina. (C,D) add mutant retinas expressing Myc-tagged N-Tcf3 labeled with anti-Myc antibody (D, green) and anti-BrdU antibody (red). The introduction of N-Tcf3 inhibits BrdU incorporation in the add mutant retina (arrowhead). (E,F) Two-dpf wild-type retinas expressing GFP-tagged 47-ß-catenin. The retinal epithelium is folded in the same way as that of add mutants (E, arrowheads). Nearly all of the retinal cells are GFP positive (inset, F) and BrdU positive (F, red), indicating that retinal cells expressing 47-ß-catenin are mitotic. (G,H) Wild-type retinas injected with a mixture of the constructs pCS2[hsp:47-ß-catenin-GFP] and pCS2[hsp:EGFP]. BrdU incorporation (red) is observed in cells expressing 47-ß-catenin (green) in the central retina. Arrowheads and asterisk indicate BrdU-positive (yellow) and BrdU-negative 47-ß-catenin-expressing cells (green), respectively. (I,J) Wild-type retinas injected with a mixture of the constructs pCS2[hsp:47-ß-catenin-GFP] and pCS2[hsp:myc-hdac1]. BrdU incorporation (red) is suppressed in retinal cells co-expressing Hdac1 and 47-ß-catenin (arrowheads, green).