Fig. 9

Gene expression at 25 days post-amputation in worms that have been treated with Decitabine during regeneration. WMISH at 25 dpa of posterior parts of control worms and worms treated with 50 μM Decitabine from 0 to 5dpa for selected markers, i.e., Pdum-engrailed (Pdum-en; segmental stripes), Pdum-dlx (parapodia and anal cirri), Pdum-hox3 (growth zone), Pdum-caudal/cdx (pygidium and growth zone), and Pdum-piwiB (growth zone and segmental progenitors). Two Decitabine-treated worms with more or less altered morphologies (class 1 and class 2/3) are shown for each gene. In A1–A3, black arrowheads point to segmental stripes of Pdum-en expression. In A2, the double black arrowhead points to an incomplete expression stripe. In B1–B3, brown arrowheads point to the expression of Pdum-dlx in developing parapodia. In B3, a reduced Pdum-dlx expression is observed on one side of the worm (double brown arrowhead). In C1, red bracket delineates the expression of Pdum-hox3 in the ectodermal growth zone. A very large domain of Pdum-hox3 is found in class 1 worms (red bracket in C2). An abnormal expression pattern is also observed in class 2/3 worms (red bracket and double red arrowhead in C3). In D1–D3, blue arrows point to the expression of Pdum-cdx in the posterior gut region and double blue arrows point to an ectopic expression of the gene in developing segments (D2). In E1–E3, red bracket delineates a strong expression of Pdum-piwiB in the mesodermal growth zone. Pdum-piwiB is also expressed in the developing mesoderm in a graded manner. In E2, a strong and broad expression is found throughout the regenerated region (red bracket and double red arrowhead)