Fig. 2

Live time-lapse analysis of cell movements in WT and MZlurap1 embryos. The initial and final positions of 20 randomly selected cells are labelled by coloured dots, and their movement trajectories are traced. Representative images selected from time-lapse movies are positioned with the anterior region on the top. a, b First and last images show the convergence of lateral cells towards the notochord in a WT embryo. c, d First and last images show the movement behaviours of lateral cells in a MZlurap1 embryo. e Scatter plot shows the net distance, represented by the horizontal arrow in the inset, reached by lateral cells towards the notochord during convergence in WT and MZlurap1 embryos. Bars represent the mean values ± s.d. from three independent experiments (****P < 0.0001; Student’s t-test). f, g First and last images show the anterior extension of notochord cells in a WT embryo. h, i First and last images show the movement behaviours of notochord cells in a MZlurap1 embryo. j Graph shows the net anterior extension, represented by the vertical arrow in the inset, reached by notochord cells located at three different anteroposterior positions, as represented by the coloured horizontal lines in the inset. Bars represent the mean values ± s.d. from three independent experiments (****P < 0.0001; NS, not significant; Student’s t-test). The three positions (P1, P2, and P3) are selected at the middle region of the anteroposterior length in both WT and MZlurap1 embryos, and located at a distance of 20, 50, and 80 µm anterior to the arbitrary reference position (P0), respectively. Scale bar: a–d, f–i 50 µm