(A–B) Whole mount immunodetection of GFP that highlights the ducts (green), mCherry (red) for β-cells and Sst (gray) on the entire pancreas of Tg(nkx6.1:eGFP); Tg(ins:NTR-P2A-mCherry) larvae at 17 dpf. (A) CTL larvae showing the main islet in the head and a few monohormonal endocrine cells (mCherry+ or Sst+) in the ductal GFP+ domain in the tail. The pancreatic tail is delineated by white dashed lines. (B) After treatment with NFP from 3 to 4 dpf, regenerating larvae display scattered bihormonal cells (red and gray) in the tail along the ducts. Stacks represent 3D projections of confocal images of the whole pancreas. (B’) Close-ups of two individual bihormonal cells in the tail (z-planes showing one unique optical section). (C) Quantification of Sst + mCherry + bihormonal cells based on confocal images. Mann-Whitney test, ****p < 0.0001. (See also Figure 7—source data 1).
