Figure 4

Time evolution of strain around the axial plane in the M-L, A-P and radial (‘r’) directions. (A) The dorsal view of the embryo at 8, 10, 10.5 and 11 hpf of zebrafish development. Strain is calculated along the embryo anterior–posterior axis corresponding to the dorsal (solid white band) and ventral (dashed white band) midline of the embryo. Scale bar—100 µm. (B–D) Kymograms of dorsal (left panels) and ventral (right panels) strain in the M-L (B), A-P (C), and radial, ‘r’ (D) directions and from 7.5 to 11.5 hpf (x-axis). The Y-axis measures strain around the anterior–posterior plane (white band in (A) of the embryo) from the anterior (0°) to the posterior side (180°). Dashed lines correspond to stages in (A). The white dotted line across the posterior side between 8 and 9 hpf indicates the margin of dorsal closure.