Figure 4

Inhibition of GSK3β leads to expansion of retinal progenitor markers. (A, B) In situ hybridization with an rx1 riboprobe. Control zebrafish embryos at 72 hpf express rx1 in the CMZ at the retinal margin (A; bracket). In contrast, embryos treated with 1-azakenpaullone from 24 hpf to 72 hpf show a marked expansion in the domain of expression of rx1, marking an expanded CMZ (B; bracket). (C, D) Sections through retinas labeled via in situ hybridization with a sox2 riboprobe. Control retinas show sox2 expression within the CMZ (arrows) and in developing amacrine cells (C). 1-azakenpaullone-treated retinas have sox2 expression throughout the retina (D). (E, F) Sections through retinas labeled via in situ hybridization with a vsx2 riboprobe. Control retinas show vsx2 expression within the CMZ (E; arrows). 1-azakenpaullone-treated retinas have vsx2 expression throughout the retina (F).