Fig. 6. bHLH gene expression in the mutant retina. In situ hybridization was performed with E17.5 retina. (A,B) Math3 expression is not changed in NeuroD^–/– retina. (C,D) NeuroD expression is not changed in Math3^–/– retina. (E,F) Math5 expression is upregulated in Math3^–/–/NeuroD^–/– retina, suggesting that this upregulation leads to the increase of ganglion cells in the double-mutant retina. Scale bar: 15 µm.