Fig. 8. Effects of Shh on organization of the regenerating retina. Eyes that were treated with KAAD/Fgf2 (A,D,G,J), Fgf2 only (B,E,H,K) or Rcas-Shh/Fgf2 (C,F,I) were collected at E11 (A-F) or E15 (G-K) and were subjected to immunohistochemical analysis. Brn3a and Napa-73 immunoreactivity in E11 KAAD/Fgf2-treated eyes suggests that there are more ganglion cells and nerve fibers in both the CB/CMZ regeneration (A1) and retina that arises from transdifferentiation of the RPE (D1) when compared to the Fgf2-treated controls in (B1) and (E1) respectively. When eyes were treated with Rcas-Shh/Fgf2, regeneration from the CB/CMZ (C1) and from transdifferentiation (F1) seem to have a reduced NFL and number of ganglion cells. There seem to be no difference in the expression patterns of Pax6 and Chx10 in KAAD/Fgf2 (A2,D2) or Rcas-Shh /Fgf2 (C2,F2) when compared with the Fgf2-treated controls (B2,E2, respectively). There are no major differences in the expression of visinin and Mitf in the CB/CMZ regenerate when comparing KAAD/Fgf2-treated eyes (A3) with Fgf2-treated eyes (B3) and Rcas-Shh/Fgf2-treated (C3) eyes. There is also no difference in the expression of visinin in retina that regenerated by transdifferentiation, when we compare KAAD/Fgf2-treated (D3) with Fgf2 (E3) and Rcas-Shh/Fgf2-treated (F3) eyes. Similar patterns are observed at E15. Expression patterns of Pax6 and Chx10 are comparable among KAAD/Fgf2-treated (G2 and J2), Fgf2 only (H2 and K2) and Rcas-Shh/Fgf2-treated (I2) eyes. At E15, visinin is present while Mitf is absent in all transdifferentiated retina that arises in KAAD/Fgf2-treated eyes (J3) and control (K3) eyes. Scale bar: 50 µm.