Figure 4

Notch1^ICD directly regulates proliferation and blocks endocrine differentiation. (A-F). Confocal sections of chicken embryonic pancreata 52 hours after electroporation with empty vector (A-C) or Notch1^ICD (D-F) subjected to immunohistochemical stainings against glucagon (red), and insulin (blue) (A and D), Nkx6.1 (red) (B and E), and MPM2 (red) (C and F). GFP was detected by its endogenous fluorescence (A-F). Inserts in A-F show higher magnifications of the boxed areas in the cognate panels. (G) Bar graph illustrating the quantitative analysis of endocrine differentiation 52 hours after electroporation with control vector or Notch1^ICD plasmid at HH st. 13–15. Note the absence of insulin and glucagon and the presense of MPM2 in GFP-positive cells in the Notch1^ICD electroporated embryos.