Fig. 3.

Robo receptors are required for cell survival and proliferation of ventral pancreatic progenitors. a Representative IF images of E9.5 CTRL and Robo1/2 KO cryosections stained for Ecad, Prox1 and cleaved-Caspase3 (Cas3). Hoechst (Hoe) nuclear counterstain. Arrowhead indicates apoptotic nucleus; in yellow insets are shown Hoechst and Cas3 single channels. Scale bars, 50 µm. b Quantification of Cas3⁺ cells in ventral pancreata of E9.5 CTRL (n = 4) and Robo1/2 KO (n = 6) embryos. Number of Cas3⁺ cells was normalised to the sum of the pancreatic Ecad⁺ epithelial areas (μm²). c Representative confocal maximum intensity z-projections of whole-mount IF for Pdx1 and Sox17α on E10.5 CTRL and Robo1/2 KO embryos. White dashed line marks ventral pancreatic bud; yellow dashed line marks dorsal pancreatic buds. Absence of Sox17⁺ ventral pancreatic bud in KO embryo is indicated by yellow asterisk (*). Scale bars, 50 µm. d Quantification of E9.5 and E10.5 ventral pancreas volume from confocal images of CTRL and Robo1/2 KO embryos. e Representative IF images of E10.5 CTRL and Robo1/2 KO cryosections stained for Pdx1, phospho-Histone H3 (pHH3) and Ecad. Scale bars, 50 µm. dp dorsal pancreas, vp ventral pancreas. f Quantification of proliferation in ventral pancreatic buds of E9.5 and E10.5 CTRL and Robo1/2 KO cryosections. Number of pHH3⁺ cells was normalised to the sum of the Ecad⁺ epithelium area (µm²). Error bars represent ±s.e.m. Two-tailed Student’s t-test *P < 0.05, **P < 0.01