The histone variant macroH2A confers functional robustness to the intestinal stem cell compartment
Fig 4
Reserve ISC frequency and activity in macroH2A DKO intestine.
(A) Left: representative flow cytometry plots of SSC-A vs. Hopx-tdTomato+ signal in proximal small intestine crypt cells from macroH2A WT or DKO mice. Right: quantitation of Hopx-tdTomato+ population as a percentage of crypt epithelial cells. N = 5 mice per condition, mean ± SD. (B) Top: homeostatic lineage-tracing scheme: macroH2A WT and DKO Hopx-CreERT2::Rosa26-LSL-tdTomato mice were injected with 2mg tamoxifen for 2 consecutive days followed by a 2-week chase. Bottom: representative anti-tdTomato immunofluorescence (red) counterstained with DAPI (blue) of macroH2A WT and DKO proximal jejunum 2-weeks after induction of Hopx-tdTomato lineage tracing. 4x objective. (C) Left: quantitation of percentage of villi with tracing events after 2 week chase, N = 3 mice per condition, mean ± SD. Right: percentage of villi with tracing events normalized to percentage of Hopx-tdTomato+ ISCs during homeostasis (values in Fig 4A). N = 3 mice per condition, mean ± SD. (D) Left: representative flow cytometry plots of EdU content vs. DAPI of within Hopx-tdTomato+ subpopulations of macroH2A WT and DKO proximal jejunal crypt cells. Right: quantitation of Hopx-tdTomato/EdU double positivity as defined by boxed subpopulation on left. N = 7 mice per condition, medians, quartiles and ranges of values shown. *p<0.05, ns = not significant, Student’s t-test. Scale bar = 100μm.