Fig. 8.

Wnt/β-catenin signalling is necessary for cell proliferation and survival. a Proliferating cells labelled by incorporation of 5-ethynyl-2′-deoxyuridine (EdU, red) from 6 to 7 dpf and counterstained with DAPI (blue) to mark cell nuclei. Images are maximal projections of the whole fluorescent confocal z-stacks. Representative individuals are shown. b TUNEL staining of cell death (green), counterstained with Hoechst dye (blue) to mark nuclei. c Number of EdU positive proliferating cells in the whole larvae as counted manually on maximal projections of fluorescent z-stacks as those shown in (a). Averages are indicated in bold, n—number of individuals analysed per each experimental group, p—p value of a standard two tailed unpaired Student’s t test with unequal variance, s.d.—standard deviation. There are significantly less proliferating cells when IWR-1-endo is present. With the activator of Wnt/β-catenin signalling CHIR99021, there is no significant difference in the number of proliferating cells throughout the body. d Quantification of cell death performed in the same way as for proliferation, except only cells from the trunk up to midgut/pharynx boundary (or up to first pair of parapodia) were counted. There are significantly more dead or dying cells in groups treated with CHIR99021 or IWR-1-endo compared to control group which was treated with DMSO