FIGURE 5.

Meis2 is expressed in the majority of Tbr2-expressing displaced amacrine cells and in a subset of Tbr2-expressing RGCs. (A) Flatmounted retina of a control (Tbr2^CreER/+;tdT) mouse immunostained to reveal expression of tomato (red), Meis2 (green), and RBPMS (blue). First image is a merge of all color channels, others are showing each channel independently; arrows point to Tomato⁺ ACs expressing Meis2; closed white circles represent Tomato⁺ RGCs expressing Meis2; dashed white circles indicate Tomato⁺ RGCs that do not express Meis2. All Tomato⁺ ACs in this image express Meis2. (B) Quantification of the density (cells/mm²) of cell populations of interest in control and Tbr2^KO mice (n = 3 mice in each group, each dot represents the sum of 4 FOVs per retina, mean ± SEM displayed; two-way ANOVA with Sidak’s multiple comparisons test; no significant differences). There is a trend toward a decrease in the density of labeled amacrine cells in Tbr2^KO mice. (C) Quantification of the percentage of Tomato⁺ cells that belong to cell populations of interest in control and Tbr2^KO mice (n = 3 mice in each group; each dot represents the percentage for 4 summed FOVs of 1 retina; mean ± SEM displayed; two-way ANOVA with Sidak’s multiple comparisons test; no significant differences).