Extended Data Fig. 4 | Mini-gut tubes undergo rapid cell turnover and
comprise key functional intestinal cell types. a, Epithelial tissue turnover
assessed through EdU pulse-chase experiments. Ten-day-old mini-guts were
treated with EdU for 12 h basally and apically, followed by a chase period of four
days. At 0 h after EdU removal, the majority of EdU+ cells resided within the
crypts and adjacent regions. A 24-h EdU pulse-chase revealed distinct regions
of cell proliferation that were to a large extent restricted to the crypts. Two days
after the EdU pulse, numerous EdU+ cells were found in the lumen, suggesting
the occurrence of intestinal epithelial cell migration from the crypts to the
villus-like domains. Labelled cells were virtually absent four days after the EdU
pulse, suggesting that tubular mini-guts underwent full turnover of the
epithelium. Data are representative of one EdU labelling experiment with n = 2
replicates per condition. Scale bars, 50 μm. b, Micrograph of a mini-gut tube
removed from the microchip for downstream histological sectioning and
analysis. Scale bar, 200 μm. c, Histological cross-sections of 7-day-old mini-gut
tubes stained with Alcian Blue showing acidic polysaccharides of the mucus
layer (blue) counterstained with Nuclear Fast Red. The entire perpendicular
section (left) and a higher magnification view of the goblet cells (right) are
shown. Similar results were obtained for 10 sections from two biologically
independent samples. Scale bars, 20 μm. d, Transmission electron microscopy
cross-sectional views of 7-day-old mini-gut tube. Goblet cell (left; scale bar, 2
μm) and enterocyte brush border (right; scale bar, 0.3 μm). Data are
representative of two samples. e, Gradual increase in aminopeptidase activity
after induction of differentiation in mini-gut tubes. Mean ± s.d. from n = 3
biologically independent experiments.