Fig. 4: Persistent labeling of cells within developmental compartments during regeneration.

a Time lapse ventral confocal stack projections of the regenerating tail tip of a worm displaying clonal transgene expression in the ectodermal lineage. b–d magnified confocal sections of the same individual. e, f interpretative schemes of c and d. The time-lapsed views illustrate the continuity of clonal expression of the transgene in epidermal cells (a, stage 1), undifferentiated blastema cells (b), regenerated PSCs (c, d) and progenitor cells (c, d). g–l Regeneration experiments on animals bearing simple clones. Dorsal views of confocal stack projections, with pre-amputation views on top and the matching full regenerates (3 weeks post amputation) on the bottom. This series illustrates the strict compartment restriction in the regeneration of ectoderm-derived and mesoderm-derived PSCs, as well as gut endodermal lineage. Pygidial ectoderm, entirely removed upon amputation, is regenerated exclusively from trunk ectoderm precursors (g, j). For all panels, green labelings are cell membranes, magenta labelings are cell nuclei. White arrows: position of rings of PSCs in the respective focal plane. Scale bars a = 100 µm; b, c = 10 µm; d = 20 µm; g–l = 100 µm;.