(A and B) Whole-mount LacZ labeling of Pdx1 progeny in E9.5 embryos shows distinctively formed pancreatic buds in both controls (A) and DKO embryos (B). A LacZ-positive region (arrowhead) was also detected in the hypothalamus region, as reported by Wicksteed et al. (53). (C and D) Representative sections of the pancreatic region from embryos shown in A and B confirm the presence of the dorsal and ventral buds in both control (C) and DKO embryos (D). (E and F) Whole-mount LacZ staining of Foxa3 lineage cells in control and embryos deleted for Gata4 and Gata6 in the Foxa3-Cre prepancreatic endodermal domain. Similar to the phenotype of embryos deleted for Gata4 and Gata6 in the later Pdx1 domain, dorsal and ventral pancreatic buds form in control E11.5 embryo (A) and in Foxa3-cre;Gata4fl/fl;Gata6fl/fl embryos (B). dp, dorsal pancreas; vp, ventral pancreas. Original magnification, ×40 (A and B); ×100 (C and D); ×80 (E and F).