Fig. 1. Expression of Arx in developing mouse OB. Parasagittal sections of E11.5 (A), E12.5 (B), E14.5 (C), E16.5 (D), P0 (E), and P60 (F) wild-type mice were labeled with anti-Arx antibody (red) and counterstained with PI (blue: nucleus). Note that Arx is expressed in the olfactory bulb (OB) and rostral migratory stream (RMS), but not in olfactory epithelium (OE), at all the stages. Arrowheads in B: OB anlagen. Signals in the OE at P60 are non-specific autofluorescence (F). (G-V) Coronal sections of P0 wild-type mouse OB. (G-J) A triple-labeled section for Arx (red in G,J), Tbx21 (green in H,J: mitral cells), and DAPI (blue in I,J: nucleus). Arx is not expressed in Tbx21(+) mitral cells. (K-R) A triple-labeled section for Arx (red in K,N,O,R), GABA (green in L,N,P,R), and TH (blue in M,N,Q,R). (O-R) A magnified view of the glomerular layer (GL). Arrowheads in (K-R): Arx(+), GABA(+), and TH(+) periglomerular cells in the GL. Arrows in (K-N): Arx(+) and GABA(+) granule cells in the granule cell layer (GCL). (S-V) A magnified view of the GCL. A triple-labeled section for Arx (red in S,V), GABA (green in T,V: granule cells), and GLAST (blue in U,V: radial glia). Arrows in (S-V): Arx(+) and GABA(+) granule cells. Arrowheads in (S-V): Arx(+) and GLAST(+) radial glia. GE, ganglionic eminence; LGE, lateral ganglionic eminence; MCL, mitral cell layer; MGE, medial ganglionic eminence; ONL, olfactory nerve layer. Scale bars: in F, 200 µm for A-F; in J, 100 µm for G-J; in N, 40 µm for K-N; in V, 20 µm for O-V.