Fig. 1. Cell behaviour during mitosis in the early neural tube. (A) Slice culture method; DNA is electroporated into the neural tube, embryo slices mounted on coverslip-based dishes and imaged on a Deltavision widefield microscope. (B) Cell membrane label (Gap43-mRFP1) reveals basal process retention during mitosis. Maximum intensity projections (MIP) of 15 z-sections, captured at 2.5 µm intervals. White broken line indicates the apical surface; scale bar: 10 µm. (C) Gap43-mRFP1 (red) visualizes initiation and progression of the cleavage furrow around the centre of the dividing cell (white arrows), whereas eYFP--tubulin (green) reveals the mitotic spindle, formation of the midbody by the central mitotic spindle (yellow arrow) and the contribution of this structure to two new apical processes on completion of cytokinesis (blue arrows). Images are MIP of 15 z-sections of each wavelength captured at 2.5 µm at 1.5-minute intervals. (See Movie 1 in the supplementary material.) Scale bar in C, 10 µm.