FIGURE 7.

Effects of misexpressed Ldb1 on the differentiation of retinal cell types and subtypes. (A–J,A’–J’) Ldb1-GFP or control-GFP retroviruses were injected into the subretinal space at P0 and retinas were collected at P21 for analysis. (A–C,A’–C’) Misexpressed Ldb1 promoted the differentiation of Chx10⁺ bipolar cells, PKCα⁺ rod bipolar cells and Bhlhb5⁺ type 2 OFF-cone bipolar cells. (D–F,D’–F’) Misexpressed Ldb1 promoted the formation of Pax6⁺ amacrine cells, GLYT1⁺ glycinergic amacrine cells and GAD65⁺ GABAergic amacrine cells. (G–I,G’–I’) Misexpressed Ldb1 promoted the differentiation of Müller cells positive for Sox9, GS or Lhx2. (J,J’) Misexpressed Ldb1 decreased the number of recoverin⁺ photoreceptors. (K,L,K’,L’) E13.5 retinal explants were infected with Ldb1-GFP or control-GFP retroviruses and collected for analysis after 4.5 days in culture. Misexpression of Ldb1 increased Brn3a⁺ ganglion cells and Lhx1⁺ horizontal cells. (M) Quantification of GFP⁺ cells that become immunoreactive for a series of cell type-specific markers. Each histogram represents the mean ± SD for three retinas. A range of 400–3696 GFP⁺ cells was scored in each retina depending on the abundance of co-labeled cells. ^∗p < 0.05, ^∗∗p < 0.005. Arrows point to representative colocalized cells and insets show corresponding outlined regions at a higher magnification. BC, bipolar cell; GCL, ganglion cell layer; GS, glutamine synthetase; INL, inner nuclear layer; IPL, inner plexiform layer; ONL, outer nuclear layer; OPL, outer plexiform layer. Scale bar: (A-L,A’-L’) 20 μm.