Deletion of Tcfap2a and Tcfap2b leads to loss of retinal horizontal cells. A–H: Horizontal sections of control (A,C,E,G) and Tcfap2a/b mutant (B,D,F,H) peripheral retinas immunolabeled (green) with anti-LIM1 (A–D), anti-neurofilament medium chain (NF-M; E,F) or anti-PGP9.5 (G,H) antibodies and counterstained with DAPI (4,6-diamino-2-phenylindole; blue) at E16.5 (A,B) or P0 (C–H). onbl, outer neuroblast layer; INL, inner nuclear layer; GCL, ganglion cell layer. Scale bars = 100 µm.