Movie 1

VBW TAGLN cells migrate towards the ventral midline. Nine hours time-lapse of E11.5 Tagln-Cre:Rosa26-tdTom:PAX3-GFP body wall explant. The location corresponding to the video is marked in (Fig. S2A). Td-Tom⁺ cells of the primary body wall migrate ventrally towards the midline, while dorsal tdTom⁺ cells showed little movement and on a different axis. The myofibroblast of the primary body wall are located more ventrally to the PAX3 GFP⁺ cells of the somite. Many of the primary body wall myofibroblasts (ventral to the somite) are showing weak tdTom signal (due to short time since Cre activation and hence little accumulation of the tdTom protein) but can be seen displacing ventrally as well. The centre of each tracked cell is labelled with a grey sphere and the path and time course of the migration track is shown in a “dragon tail” style. Each cell drags the migration path behind, the migration track is shown in a gradient rainbow-coloured line where blue represents position at the start of the time-lapse and “red” the end position. Time between frames is 10 minutes and movie played at 6 frames per second.