Fig. 1

Cells on the neural ridge underwent backward movement after the completion of mid-hindbrain neuropore (MHNP) closure. a Time-lapse montages of the MHNP closure under live-imaging condition. Maximum z-projected images of dorsal views of the MHNP are shown. Identical cells are connected by each dotted line. b Magnified views of the navel in another embryo. Cells (labeled with colors) gathered near the navel and were relocated. c The plot of cell-cell distance between a standard cell (marked with star in (b)) (Y-axis) and each cell along time-points (X-axis). Each color corresponds to those of labeled cells in (b). d Representative examples of cell relocation around the MHNP in the embryo shown in (a). Cells on the neural ridge are labeled by numbers, and changes in their position are shown during the MHNP closure. e Distance ratio (D_{598 min}/D_{164 min}) relative to cell 1, which was selected as a standard cell within the navel. Cells located apart from the navel showed a larger distance ratio (D_{598 min}/D_{164 min}), indicating that those cells rapidly leave the navel regions. f Time-lapse montages of transverse (xz) sections reconstituted from 4D (x, y, z, t) dataset during the MHNP closure in (B-C). A dotted line in left panel (xy images) indicates the position for making xz sections shown in right panels. Scale bars: (a, b, f) 50 μm (d) 10 μm