Fig. S1

Fig. S1 Wnt8a overexpression induces the direct conversion of non-hepatic endodermal cells into hepatoblasts, but not the posterior migration of hepatoblasts. Wild-type or Tg(hs:wnt8a) embryos were co-injected with sox32 and kikume mRNA into a single cell at the 32-cell stage. Endodermal cells at the 1st or 6th somite level were photoconverted at 25.5 hpf and then heat-shocked. The embryos were harvested at 40 hpf and processed for immunostaining. (A-C) Endodermal cells at the 1st somite level were photoconverted for lineage tracing. A′ and B′ images are the same as A and B, respectively, but without Pdx1 and Kik^green expression. B′′ is the same image as B′ but without Prox1 expression. Cartoons incorporating all lineage-tracing data (C) show that the posterior migration of hepatoblasts in the liver-forming region did not occur in Wnt8a-overexpressing embryos. (D-G) Endodermal cells at the 6th somite were photoconverted for lineage tracing. Kik^Red+ cells expressed Prox1 (green) in Wnt8a-overexpressing embryos (F, open arrowheads), but not in controls (D′). Higher magnification images of the square region in E are shown in F without Pdx1 and Kikgreen expression. F′ is the same image as F but without Prox1 expression. Cartoons incorporating all lineage-tracing data (G) show that non-hepatic endodermal cells were converted into hepatoblasts upon Wnt8a overexpression. Green and blue lines outline Prox1+ and Pdx1+ domains, respectively, and n indicates the number of embryos (C,G). Dotted lines outline the dorsal pancreas (DP), and brackets delineate the endode rmal region in which ectopic hepatoblasts are present. All confocal images are ventral views with anterior up. Scale bars, 20 µm.