Expression of Tfap2b in amacrine and horizontal cells. (A-L) Sections from P21 mouse retinas were double-immunolabeled with an anti-Tfap2b antibody and those against the indicated cell type-specific markers. Tfap2b is expressed in amacrine cells co-expressing Pax6 (A), syntaxin (B), GABA (C), Gad67 (D), Gad65 (E), Bhlhb5 (F), Nr4a2 (G), ChAT (H), GLYT1 (I), Ebf (J), or calbindin (K). It is also expressed by horizontal cells co-expressing calbindin or Lim1 (K, L). However, there is no expression of Tfap2b in Bhlhb5+ bipolar cells within the outer half of the INL (F). Abbreviations: GCL, ganglion cell layer; INL, inner nuclear layer; IPL, inner plexiform layer; ONL, outer nuclear layer. Scale bar: A-L, 47.6 μm.