hnf1ba and wnt2bb cooperate to specify the hepatopancreas organ system after mid-somitogenesis. (A-F) Three-dimensional rendering of 80 hpf Tg(ptf1a:eGFP)jh1; Tg(lfabp:dsRed)gz2 (pancreas, green; liver, red) foregut endoderm in wild type (A), wnt2bbs404 mutant (B), hnf1bas430 mutant (C) and wnt2bbs404; hnf1bas430 double mutants (D-F) stained for cadherin (epithelial endoderm) and with monoclonal antibody 2F11 to mark extra hepatopancreas ducts (*) (dashed outline). Relative to wild type, the wnt2bbs404 mutant liver (L) and the hnf1bas430 mutant pancreas (P) are reduced in size. The wnt2bbs404; hnf1bas430 double mutant liver and pancreas (arrow) are more severely reduced, or lost. Double mutants can exhibit complete loss of the hepatopancreas system (E,F; white arrowheads). (G,H) Three-dimensional rendering of 80 hpf Tg(ptf1a:eGFP)jh1 (pancreas, green) foregut endoderm in wild-type (G) and wnt2bbs404; hnf1bas430 double mutants (H) stained for cadherin and Isl1 to mark the hepatopancreas mesenchyme (brackets) and islet (I). Double mutants lacking the entire hepatopancreas system still develop Isl1+ mesenchyme and islet (yellow arrowheads indicate the swimbladder). (I) Merged fluorescent/brightfield micrographs of 4 dpf Tg(ptf1a:eGFP)jh1; Tg(lfabp:dsRed)gz2 wnt2bbs404 mutant (top) and wnt2bbs404; hnf1bas430 double mutants (bottom) showing no obvious body phenotypes other than liver and pancreas agenesis (arrows). (J,K) Three-dimensional rendering of 80 hpf foregut endoderm, heat-shock-induced Tg(hsp70l:dkk1-GFP)w32; Tg(ptf1a:eGFP)jh1; Tg(lfabp:dsRed)gz2 and Tg(hsp70l:dkk1-GFP)w32; hnf1bas430; Tg(ptf1a:eGFP)jh1; Tg(lfabp:dsRed)gz2 stained for cadherin and with 2F11. Heat-shock-induced expression of dkk1-GFP in wild-type background does not lead to liver or pancreas agenesis (J), whereas in the hnf1bas430 mutant background, the hepatopancreas system is completely lost (K) (white arrow). The swimbladder (yellow arrowhead) is not lost in wnt2bbs404; hnf1bas430 double mutants or in heat-shock-induced Tg(hsp70l:dkk1-GFP)w32; hnf1bas430 mutants (D-F,H,K).