Fig. 6

Decitabine treatment decreases DNA methylation level and impairs larval development. a Schematic representation of the experimental design. Larvae were treated with Decitabine (50 μM), RG108 (50 μM), or DMSO (0.5%; control) from 1 day post-fertilization (1dpf) to 3dpf. At 3dpf, a part of the batch of larvae was frozen for subsequent DNA methylation measurement with LUMA and remaining larvae were placed and kept in normal sea water until 14dpf. Observations were done at indicated time points and pictures taken at 3, 5, and 14dpf. b Graphic representation of CCGG DNA methylation as measured by LUMA for the different conditions (two or three biological replicates per condition and two technical replicates per biological replicate). Mean ± SD. One-way ANOVA, Dunnet post hoc test was performed (***: p < 0.001). The raw data can be found in Additional file 2: Table S2. c Morphological observations at 3, 5, and 14dpf. Ventral views of representative larvae/juvenile worms are shown (anterior on the left). At the three time points, RG108-treated larvae/juvenile worms show morphologies similar to those of controls (sea water and DMSO 0.5%). At 14dpf, like the control animals, RG108-treated worms have added a fourth segment. In contrast, at 3 and 5dpf Decitabine-treated larvae/juvenile worms display an abnormal morphology with strongly reduced appendages (parapodia; arrows) and a reduced pygidium (arrowheads). Massive death occurred in the 5 to 9dpf time period, so no Decitabine-treated worms could be observed at 14dpf. These experiments were performed twice using larvae from independent fertilizations