Figure 1. Stimulation and inhibition of transdifferentiation

A: Schematic of an intact eye at E4. B: Schematic of a transdifferentiating eye three days after retina removal. Boxed area demonstrates orientation of C-H. F represents FGF2 bead. All eyes underwent retinectomy at E4 (C-H). C: Infection of the RPE with Rcas-MEK^DD at E4 induced transdifferentiation by E7. AMV3C2 staining represents the presence of the Rcas virus in the RPE. D: Infection of the RPE with Rcas-Pax6 at E4 induced transdifferentiation by E11. AMV3C2 staining represents the presence of the Rcas virus in the RPE. E: Infection of the RPE with Rcas-Mitf at E4 is able to inhibit transdifferentiation stimulated by FGF at E7. AMV3C2 staining represents the presence of the Rcas virus in the RPE. Only areas of the RPE that were not infected with Rcas-Mitf were able to transdifferentiate. F: Infection of the RPE with Rcas-MEK^DD at E4 induced transdifferentiation by E11. Some of the transdifferentiated RPE started to differentiate and express the photoreceptor marker visinin (green). Tissue was counterstained with DAPI (blue). G: Infection of the RPE with Rcas-Pax6 at E4 induced transdifferentiation by E11. Some of the transdifferentiated RPE starts to differentiate and express the photoreceptor marker visinin (green). Tissue is counterstained with DAPI (blue). H: Infection of the RPE with Rcas-GFP control did not induce transdifferentiation. AMV3C2 staining represents the presence of the Rcas virus in the RPE. Dashed lines outline the RPE and areas of transdifferentiation. Note: For C and D only infected RPE responded by transdifferentiating. L represents lens; RPE represents retina pigmented epithelium; tr represents transdifferentiation; r represents retina. Infected mesenchyme (m) did not transdifferentiate. Scale bar in H represents 50 μm and applies to A-H.