Fig. 5. The fate switch from amacrine cells to ganglion and Müller glial cells in Math3^–/–/NeuroD^–/– retina. (A) X-gal staining of the retinal explants that were prepared at E17.5 and cultured for 14 days. (a) In NeuroD^+/– retina, X-gal staining is observed in NeuroD-expressing cells: rods in the ONL and amacrine cells in the GCL and the inner region of the INL. (b) In Math3^–/–/NeuroD^–/– retina, X-gal-positive cells are not missing but present in the GCL and INL as well as in the ONL. The majority of them are small in size, while others display a Müller glia-like morphology (arrowhead). Scale bar: 25 µm. (B) Retinal explants were prepared at E17.5, cultured for seven days, dissociated and subjected to immunocytochemistry (n=3). (a-d) In NeuroD^+/– retina, some (2.7±0.3%) of the lacZ⁺ cells express the amacrine cell marker HPC1 (arrows). (e-h) In Math3^–/–/NeuroD^–/– retina, no lacZ⁺ cells express HPC1. (i-l) In NeuroD^+/– retina, no lacZ⁺ cells express the ganglion cell marker Thy1.2. (m-p) In Math3^–/–/NeuroD^–/– retina, some (4.3±0.6%) of the lacZ⁺ cells express Thy1.2 (arrows). (q-t) In NeuroD^+/– retina, no lacZ⁺ cells express the Müller glial marker vimentin. (u-x) In Math3^–/–/NeuroD^–/– retina, some (0.9±0.2%) of the lacZ⁺ cells express vimentin (arrow).