Figure 1: Hmga1 localizes to ISCs and its overexpression expands the ISC compartment in transgenic mice.

(a) ISCs from WT/Lgr5-EGFP+ mice stain green (upper panel) in small intestinal cross-sections. Hmga1 stains red and localizes to GFP+ ISCs (lower panel). (b) Intranuclear Hmga1 stains brown (immunohistochemistry (IHC)) in small intestinal cross-sections from WT/Lgr5-EGFP+ mice. (c) ISCs stain green in Hmga1/Lgr5-EGFP+ transgenic mice and extend further up the base of the crypt in Hmga1 transgenic mice compared to WT mice. (Cells with red nuclear staining outside of crypts are Hmga1 transgenic lymphocytes) (d) Intranuclear Hmga1 stains brown (IHC) in small intestinal cross-sections from Hmga1/Lgr5-EGFP+ mice. (e) Fluorescent staining identifies GFP+ ISCs at each region in the small intestine of WT and Hmga1 mice (duodenum, jejunum, ileum). (f) The percentage (mean±s.d.) of GFP+ ISCs per crypt in WT and Hmga1 transgenic mice are shown; **P<0.00001, Mann–Whitney test (n=50 crypts per region, 3 mice per genotype). Dot plot shows individual data points. (g) Hmga1 transgenic mice have higher GFP+ ISC frequency as assessed by flow cytometry; mean frequency±s.d. from two experiments are shown. (h) Hmga1 mRNA is enriched in ISCs isolated by flow cytometry for GFP+ cells using quantitative, real-time PCR (qPCR) in WT and Hmga1 transgenic mice. Hmga1 is higher in both GFP+ ISCs and GFP− crypt cells from the Hmga1 transgenic model compared to WT mice. Bars show mean relative Hmga1 expression±s.d. from three experiments performed in triplicate; Gapdh was used as a loading control; *P<0.05; two-tailed Student’s t-test. Scale bars, 20 μm.