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Fig. 4
Ventral digestive tract endoderm posterior to the hepatic domain is competent to respond to hepatogenic signals in vivo. (A-H2) transient wnt2bb-overexpression in Tg(XlEef1a1:GFP)s854 embryos at 18 hpf leads to an expansion of the liver in posterior ventral tissues visualised by Prox1 staining at 28 hpf (A-D2) and 48 hpf (E-H2). (I,J) pdx1 expression is significantly reduced in the pancreas and anterior intestinal domains (bracket) following wnt2bb-overexpression. (L) Embryos with excess wnt2bb exhibit ectopic Prox1 and strong 2F11 staining in the EHPD domain, revealing ectopic structures (arrows), compared with controls (K). (A,C,C2,E,G,G2) dorsal views (B,D,D2,F,H,H2,K,L) ventral views of projections of confocal stacks; (I,J) dorsal views; all anterior towards the top.