Fig. 5

DNA methylation and NuRD genes are expressed during most or all stages of P. dumerilii regeneration. Expression patterns obtained by whole-mount in situ hybridization (WMISH) for genes whose name is indicated at the five previously defined stages of posterior regeneration [37] are shown. All panels are ventral views (anterior is up). Red dotted lines indicate the amputation plane in worms at stages 2 to 5, delineating the regenerated region (below the dotted lines) from the segment abutting the amputation plane (above the dotted lines). At stage 1, only a wound epithelium has already formed (dark blue arrows) and red arrows point to internal cells of the segment adjacent to the amputation. At the other stages, dark blue arrows point to epithelium covering the blastema, red arrows point to mesodermal cells of the blastema or developing segments (depending on stages), red arrowheads to the mesodermal part of the growth zone, light blue arrows to ectodermal expression, including segmental ectodermal stripes, and brown arrows to the base of anal cirri. Additional expression patterns are shown in Additional file 9: Fig. S7, Additional file 11: Fig. S9, and Additional file 12: Fig. S10