URI and R-spondin levels correlate with crypt regeneration. (A) Kaplan–Meier curve for survival of URI^(+/+)Int (purple solid line; n = 3), URI^(Δ/Δ)Int (yellow solid line; n = 3), URI^{(+/+)Int-Lgr5-EGFP} (black solid line; n = 5), URI^(+/+)Lgr5 (green solid line; n = 3), URI^{(Δ/Δ)Int-Lgr5-EGFP} (red solid line; n = 8), and URI^(Δ/Δ)Lgr5 (blue solid line; n = 3) mice treated with tamoxifen diet. (B) Representative picture of H&E staining from URI^(+/+)Lgr5 and URI^(Δ/Δ)Lgr5 mice at indicated time points after tamoxifen treatment. Black arrow represents apoptotic bodies. (C) Scheme describing mosaic URI deletion in the intestinal epithelium by crossing URI lox mouse with Lgr5-EGFP-CreERT2 mouse. (D) Representative pictures of co-IF for URI and GFP in URI^(+/+)Lgr5, URI^{(Δ/Δ)Int-Lgr5-EGFP}, and URI^(Δ/Δ)Lgr5 mice at indicated time points of tamoxifen treatment. (E) Representative pictures of IF of GFP in URI^(+/+)Lgr5 and URI URI^(Δ/Δ)Lgr5 mice at survival time point after tamoxifen treatment. (F) Quantification of D. Graph representing the percentage of Lgr5⁺ crypts in URI^(Δ/Δ)Lgr5 mice over time (n = 3 per group). (G) Quantification of D. Graph representing the percentage of Lgr5⁻/URI⁺ crypts in URI^(Δ/Δ)Lgr5 mice over time (n = 3 per group). (H) Representative pictures of co-IF for URI, lysozyme, and R-spondin 1 in URI^(+/+)Lgr5, URI^{(Δ/Δ)Int-Lgr5-EGFP}, and URI^(Δ/Δ)Lgr5 mice at indicated time points following tamoxifen treatment. (I) Correlation between R-spondin 1 and URI levels (A.U., intensity measured) in URI^(Δ/Δ)Int after 6 d of tamoxifen treatment. Data represent mean ± SEM; ***, P < 0.001; Student’s t test. Pearson correlation was used in I. Scale bars represent 50 µm in D and H; and 100 µm in B and E. IF and H&E are representative of at least three independent mice.