Fig. 3. Dlx3 protein co-expresses with other Dlx family members, Pax6 and Hu in the olfactory epithelium. (A-C'') Specificity of Dlx3 antibody. (A) Section through r5 at HH11. Premigratory neural crest prominently expresses Dlx5 (broken white lines). Lower levels are also detected in otic placode (arrows). (A') HNK1+/Dlx3+/Dlx5+ (from A) otic placode (white arrowheads) and HNK+/Dlx5+ (from A) but Dlx3- (green) neural crest (white dotted lines). (B) In the trunk, Dlx5 transcripts are abundant in dorsal neural tube and emigrating neural crest. (B') No Dlx3 or HNK1 staining is noted in dorsal neural tube or neural crest. (C-C'') Cryosections of HH19-20 embryos co-stained for Dlx3 (green), pan-Dlx (red) and DAPI (blue) show overlap between two antibodies (C'', yellow) in olfactory, but not in forebrain, which lacks Dlx3, but stains with pan-Dlx (red). (D-D'') Dlx3 and Pax6 protein in forming olfactory placode (white arrowheads) at HH14. (D) Dlx3 (green) is in ectoderm proximal to forebrain (fb). (D') Pax6 (red) is in scattered cells but stronger in posterior ectoderm of future cornea. (D'') Overlay of Dlx3 and Pax6 shows some co-expression (yellow; D-D'', arrowheads). (E-E'') Dlx3 and Pax6 protein in olfactory epithelium at HH20. (E) Dlx3 (green) is found throughout the epithelium, but higher at margins. (E') Pax6 (red) is in cup-shaped olfactory epithelium. (E'') Dlx3 and Pax6 are co-expressed in many cells (yellow; E-E'', arrowheads). DAPI is in blue in D-E''. (F) By HH19, olfactory epithelium undergoes robust neurogenesis (pan-neuronal Hu is in red) and ingressing neurons are observed (arrowhead); some neurons within the epithelium are Pax6+ (green, arrows). (G) At HH21, a few neurons are also Dlx3+. (H) Nasal mesenchyme underlying olfactory pit at HH18-19 is Pax7+ (green). fb, forebrain; oe, olfactory epithelium; no, notochord.