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Fig. 1
FGF signalling is required for cell proliferation during larval tail regeneration. a Arrowheads point to expression of the FGF ligand, fgf10a, and the downstream target, pea3, become evident by 24 hpe (10/10 for both, number of experiments = 3). b fgf10a−/− fish have reduced tail regrowth compared to wild-type fish. Larvae were imaged at 72 hpe. Tail length was determined using the Measure macro in ImageJ software by placing a rectangle parallel to the body that started at the anus and finished at the caudal end of the fin fold. Unpaired t test two-tailed results in P < 0.0001 indicated as **** (sibling n = 20, fgf10a−/− n = 20, number of experiments = 3). c Expression of dlx5a and raldh2 are not strongly affected when FGF signalling is reduced. SU5402 treatment was done from 26 to 30 hpe at 10 μM concentration. This treatment is sufficient to abolish detection of the FGF downstream target pea3 (10/10 for each panel, number of experiments = 2). d Whereas in wild-type fish DNA mitosis increases after tail excision, in fgf10a−/− fish mitosis remains constant (wild type/12 hpe n = 8, wild type/18 hpe n = 8, wild type/24 hpe n = 19, wild type/30 hpe n = 21, wild type/48 hpe n = 14, fgf10a−/−/12 hpe n = 8, fgf10a−/−/18 hpe n = 8, fgf10a−/−/24 hpe n = 12, fgf10a−/−/30 hpe n = 20, fgf10a−/−/48 hpe n = 12, number of experiments = 2). Statistics performed with ordinary one-way ANOVA (nonparametric) with multiple comparisons and Sidak hypothesis testing. ****P < 0.0001, ***P = 0.0001 and **P = 0.005