Fig. 2. Shroom3 is required for apical constriction and apicobasal cell elongation in neural epithelial cells during neural tube closure. (A) Cross-section through the closing anterior neural tube of an embryo injected on one side with Shroom3-MO. Anti--tubulin staining reveals cell cortices and DAPI reveals nuclei. (a') Schematic of neuroepithelial cell shape in A. (B) Graph of apicobasal cell height and the distance between the basal cell surface and the basal limit of the nucleus for hingepoint cells in control and Shroom3-MO-injected regions at stage 18 (mean ± s.e.m.; ctl, n=12; Mo, n=11). (C) Graph of apical cell surface areas of control and Shroom3-MO-injected sides of fixed embryos in hingepoint (hp) and intermediate (int) regions of fixed embryos at stage 18 (mean ± s.e.m.; n=25). Hingepoint and intermediate regions are defined in Fig. S1 in the supplementary material. (D) Dorsal projection of stage 18 embryo to visualize apical cell surface areas. (E) Dorsal projection of stage 16 Xenopus embryo stained with phalloidin to visualize cell shapes. Cells defined as the hp and int regions are indicated by red outlines and labeled at the bottom of the panel (see also Fig. S1 in the supplementary material). Embryo has been injected on one side with Shroom3-MO.