Effect of knocking down Tfap2a and 2b expression on the formation of different retinal cell types. (A-T) Sections from retinas co-electroporated with pCIG and RNAi vectors pU6 or pU6-Tfap2ai5 and pU6-Tfap2bi4 were double-immunostained with an anti-GFP antibody and antibodies against the indicated cell type-specific markers. Simultaneous knockdown of both Tfap2a and 2b expression led to a dramatic reduction of Tfap2a- and Tfap2b-immunoreactive cells (S, T), a significant decrease of amacrine cells immunoreactive for Pax6, GLYT1, calretinin, GABA, Gad65, and calbindin (A-L), no change in the number of Chx10-immunoreactive bipolar cells and GS-immunoreactive Müller cells (M, N, Q, R), but a significant increase of recoverin-immunoreactive photoreceptor cells (O, P). Arrows point to representative colocalized cells and insets show corresponding outlined regions at a higher magnification. (U) Quantitation of GPF+ cells that are immunoreactive for various cell type-specific markers. Each histogram represents the mean ± SD for 3 retinas. More than 600 GFP+ cells were scored in each retina. Abbreviations: GCL, ganglion cell layer; INL, inner nuclear layer; IPL, inner plexiform layer; ONL, outer nuclear layer. Scale bar: A-N, Q-T, 39.7 μm; O, P, 23.8 μm.