Figure 2
Neuronal differentiation in the LVZ is asymmetric. Transverse sections of catshark habenulae following IHC using antibodies against HuC/D (green) and DCX (red) at stages 29 (A), 30 (B) and 31 (C,D). DAPI stained nuclei are shown in blue. (C) and (D) are located at medial and posterior levels of the habenulae, respectively. (E–G) are schemes of the catshark embryonic brain (lateral views; E, stage 29; F, stage30; G, stage 31), with a red line indicating the location and plane of the sections analysed and a red arrow showing the antero-posterior axis (arrow pointing towards anterior). (E1,F1,G1-3) show schemes of the habenula sections at the levels respectively indicated by the red line in (E,F,G), with the proliferative neuroepithelium shaded in light blue. (G1), (G2) and (G3) respectively correspond to sections at anterior, medial and posterior levels, labelled 1, 2 and 3 in (G). (A1,A2), (B1,B2), (C1,C2), and (D1,D2) show higher magnifications of LVZ territories boxed in (A), (B), (C) and (D), respectively. Brackets in (C,D) delineate a size extension of the PNE on the right compared to the left. White arrowheads in (A1,A2,B1,C1,D1) point to LVZ HuC/D and DCX negative cells that are maintained on the left but not the right at stages 30–31. Abbreviations: LHb and RHb, left and right habenulae; hc, habenular commissure; pi, pineal stalk; PNE, pseudo-stratified neuroepithelium. Scale bars = 100 μm in (A–D), 500 μm in (E–G).
