Loss of Math5 leads to an up-regulated expression of non-RGCs factors in Math5 -lineage cells. Retinal sections from the control (top panels) and Math5-null (bottom panels) embryos at the indicated developmental stages were immunolabeled with cell type markers (red) and anti-GFP (green). (A, B) At E13.5, many GFP+ Math5-lineage cells express BHLHB5 (A) or NEUROD1 (B) (arrows) in the Math5-null retina but not in the control retina. (C) At P3, compared to the control, more GFP+/BHLHB5+ cells (arrows) are seen in the GCL and less in the INL of Math5-null retinas. (D, E) The number of GFP+/RXRγ+ cone cells (arrows) is increased in Math5-null retinas at E13.5 (D) and P6 (E). Enlarged view of boxed regions in E is shown in E'. Scale bars equal 100 μm.