Figure 2: Sema3B binds the apical surface of neuroepithelial cells of E10.5 spinal cords.

(a) Confocal images of anti-GFP immunostaining showing binding sites of clusters of exogenous Ctrl GFP and Sema3B-GFP alone in transverse E10.5 sections, with competitive unlabelled Sema3B-Fc. Hoechst and phalloidin staining label, respectively, nuclei and neuroepithelium apical side. Specific Sema3B-GFP-binding sites strongly accumulated at the apical side (arrow) of neural progenitors. In addition, Sema3B-GFP-binding sites were also observed within the VZ. (b) Confocal images showing binding sites of clusters of exogenous Sema3B-GFP and Ctrl GFP in open-book configuration as depicted in d. Apical end feet of neural progenitors in the ventral, intermediate and dorsal parts of the spinal cord in planar view are delineated by phalloidin staining. (c) Higher magnification of a Sema3B-GFP-bound apical foot of an anaphase cell (underlying chromosomes were overlaid in blue). Scale bars (a), (b) 10 μm, (c), 5 μm.