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Fig. 8
fgf10a knockdown greatly enhances ectopic hepatocyte formation induced by Wnt8a overexpression. (A-D,I-L) Embryos obtained from crossing wnt2bb-/- with Tg(hs:wnt8a);wnt2bb-/- zebrafish (A-D) or outcrossing Tg(hs:wnt8a) zebrafish (I-L) were injected with fgf10a MO, heat-shocked at 30 hpf, and harvested at 60 (I-L) or 74 (A-D) hpf for whole-mount immunostaining. (E-H) Embryos obtained from crossing fgf10a+/- with Tg(hs:wnt8a); fgf10a+/- zebrafish were heat-shocked at 30 hpf and harvested at 72 hpf for whole-mount immunostaining. fgf10a knockdown in wnt2bb mutants did not induce ectopic hepatocytes or affect liver size (B, n=8 out of 8), but it greatly enhanced ectopic hepatocyte formation induced by Wnt8a overexpression [D (n=6 out of 6) versus C (n=7 out of 7), brackets]. The ectopic hepatocytes were located in the intestinal bulb (brackets) and occasionally in the extrapancreatic duct (D, arrow). Ectopic hepatocyte formation was also greatly enhanced upon Wnt8a overexpression in fgf10a mutants (H, n=5 out of 5). Wnt8a overexpression greatly induced Prox1 expression in fgf10a MO-injected embryos compared with controls [L (n=5 out of 5) versus K (n=3 out of 3), brackets]. Ventral views, anterior up. Scale bars: 50 μm.