Fig. S3

Further characterization of the pancreatic phenotype in Sbds^ATG MO-injected embryos. (A) At 48 hpf, both control and Sbds^ATG MO-injected ptf1a:eGFP;ins:mCherry embryos appear similar. Pancreatic progenitor cells have been correctly specified and ptf1a:eGFP-positive cells have migrated to achieve contact with the principal islet (red). (B) The Sbds^ATG MO disrupts pancreas development in a dose-dependent manner. Ptf1a:eGFP;ins:mCherry embryos were imaged at 72 hpf revealing a dose-dependent reduction in pancreatic volume (green). (C) Similar to the Sbds^ATG MO, a splice-blocking Sbds^Spl MO also disrupts pancreatic progenitor expansion (green). (D) Quantification of the pancreatic progenitor phenotype in Sbds^ATG MO- and Sbds^Spl MO-injected embryos, assessed at 72 hpf in three independent experiments. (E) Residual pancreatic cells in ptf1a:eGFP;ins:mCherry embryos injected with Sbds^ATG MO express carboxypeptidase (CPA) as detected by immunofluorescence (blue). (F) Residual pancreatic cells in Sbds^ATG MO-injected embryos are positive for trypsin expression by in situ hybridization. (G) Quantification of total islet volume in control and Sbds^ATG MO-injected embryos at 72 hpf (P=0.07). (H) The relative number of Notch-responsive progenitor cells in the developing pancreas is not affected by Sbds^ATG MO injection. Notch activity, as assessed by the transgenic Notch reporter line Tp1:hmgb1-mCherry, is ongoing in Sbds^ATG MO-injected embryos at 72 hpf. (I) Quantification of the ratio of GFP/mCherry volumes in control and Sbds^ATG MO-injected embryos.