Fig. 8. Effects of signaling inhibitors on cell proliferation and differentiation. (A-C) E5 explants were cultured without inhibitors (dark blue), with SU1498 (purple), with cyclopamine (yellow), or with SU1498 and cyclopamine (light blue) for 48 hours. Marker-positive cells per unit length retinal section were quantified and shown as ratios of BrdU⁺ (A), Islet1/2⁺ (B) or Brn3a⁺ (C) cells to the no inhibitor controls (n=9; *P<0.05, **P<0.01). (D,E) E5 retinal cells transfected with HES1-expressing construct (+) or the control plasmid (–) were cultured in collagen gels for 24 hours before treatment with SU1498, cyclopamine or both for another 24 hours. Bar graphs show BrdU⁺ (D) and Islet1/2⁺ (E) cells among transfected GFP⁺ cells (n=6; *P<0.05).