Fig. 2. The lack of amacrine cells and concomitant increase of ganglion and Müller glial cells in Math3/NeuroD double-mutant retina. The retinal explants were prepared from wild-type (a), Math3^–/– (b), NeuroD^–/– (c) and Math3^–/–/NeuroD^–/– embryos (d) at E17.5 and cultured for 2 weeks. (A) HE staining. The GCL, INL and ONL are formed in all retinal explants. (B) Immunohistochemistry for rhodopsin. There are fewer rods (rhodopsin⁺) in NeuroD^–/– (c) and Math3^–/–/NeuroD^–/– retina (d). (C) PKC-positive cells (bipolar cells) are normally generated in all retinal explants. (D) Calbindin-positive amacrine (black arrowheads) and horizontal cells (white arrowhead) are normally generated in wild-type (a), Math3^–/– (b) and NeuroD^–/– retina (c). By contrast, in Math3^–/–/NeuroD^–/– retina (d), amacrine cells are completely missing (asterisks), whereas calbindin-positive horizontal cells are normally generated (white arrowhead). (E) Amacrine cells (HPC1⁺) are missing in Math3^–/–/NeuroD^–/– retina (d). (F,G) Ganglion cells (Thy1.2⁺, p75⁺) are significantly increased in Math3^–/–/NeuroD^–/– retina (d). There are ectopic ganglion cells in the inner region of the INL of Math3^–/–/NeuroD^–/– retina (d). (H,I) The number of Müller glial cells (glutamine synthetase⁺, vimentin⁺) is slightly increased in Math3^–/–/NeuroD^–/– retina (d). Scale bar: 25 µm.