Fig. 3

sdc3 expression in the neuroepithelium correlates to regions of neurogenesis and axogenesis. Confocal images of wholemount zebrafish brains at various developmental stages stained for sdc3 expression (B, E, H, K, N and in red A, D, G, J, M) and the pan-axonal marker acetylated tubulin (C, F, I, L, O and in green A, D, G, J, M). Dorsal is to the top and rostral to the left in all panels except (D-F) where rostral is facing. Embryos were analysed at 28 hpf (A-F) and 18 hpf (G-O). In the telencephalon and diencephalon at both 18 and 28 hpf we see a high concentration of sdc3 in the neuroepithelium broadly correlating to regions of the developing axon scaffold. Occasionally an overlap is seen with tubulin stained cells indicating expression in neurons, in this case in neurons of the ventrorostral cluster (M-O) at 18 hpf (unfilled arrowhead in M and N). At 28 hpf staining is strong in the ventral telencephalon (green dashed outline) and ventrodorsal diencephalon (red dotted outline) but absent from the middle of the diencephalon (filled arrowhead in A) rostral dorsal telencephalon (asterix in A) and at the TPOC (filled arrow in A) Abbreviations; anterior commissure (AC), post-optic commissure (POC), optic recess (OR), olfactory placode (OP) dorsorostral cluster (drc), ventrorostral cluster (vrc), tract of posterior commisure (TPC) and medial longitudinal fascicle (mlf). Scale bars in C, F and I are 100 µm, Scale bars in L and O are 25 µm.