Fig. 7

Directional migration of cell types during regeneration. a-b Histograms of cell X-axis velocities, measured as overall X displacement of a track divided by the track total duration, for cells tracked in 5 anterior (top) and 5 posterior (bottom) amputees. Purple bars represent anterior migration (negative values); green bars represent posterior migration (positive values). g1: skewness; n: number of cell tracks; p: p-value for the Wilcoxon rank sum test. Plots are made for anterior amputees and posterior amputees for all cells combined (a) and for each cell type (b); hyalinocytes were not included due to low sample size. c Sample XY slice from a 4D dataset of a posterior amputee (mid-sagital plane, approximately 7.5 hpa). Arrowheads indicate migrating sliders; green arrowheads highlight sliders shown in d (boxed area). d Detail of four XY slices of the boxed region in c spaced 4 min apart. Two ventral sliders (green arrowheads) are moving posteriorly at different speeds (light green: faster, dark green: slower). A third cell of about the same size as the sliders (grey arrowhead) remains in the same location. e Detail of a 4D dataset of an anterior amputee showing mitotic activity of a migrating cell. Shown are 18 slices, each spaced 2 min apart. While moving in an anterior direction over the peritoneal lining of the lateral body wall, a slider stops, rounds-up, and divides; the daughter cells then regain the spindle shape. Notice the transient vertical structure at 12′, presumably a metaphase plate