Fig. 2: Cul4b is essential for homeostatic self-renewal and proliferation.

a BrdU label assay shows decreased self-renewal rate in KO^IEC mice. The scale bar is 50 μm. b BrdU label assay shows decreased self-renewal rate in KO^Lgr5 mice 3 days after tamoxifen induction administration. The scale bar is 50 μm. c Lineage tracing of Lgr5⁺ positive cells and their ascents (tdTomato) in the jejunum of KO^Lgr5-Tom mice and control 3 days after tamoxifen induction. The scale bar is 50 μm. d The representative images and quantification of PCNA positive staining cells of WT and KO^IEC mice (N = 3). The scale bar is 50 μm. ****P < 0.0001. e The representative images of organoids of passage 2 derived from WT and KO^IEC mice cultured in differentiation medium (DM). The scale bar is 400 μm. f The average number of buddings per organoid derived from WT and KO^IEC mice (N = 3). Error bars represent standard errors. *P < 0.05, ****P < 0.0001. g The representative images of organoids at passage 2 derived from WT and KO^IEC mice cultured in expansion medium (EM). The scale bar is 400 μm. h Colony-forming effciency of organoids cultured in expansion medium from KO^IEC and WT mice. Error bars represent standard errors. ****P < 0.0001. i Whole-mount staining of Ki67 in intestinal organoids from WT and KO^IEC mice. The scale bar is 50 μm. j GSEA analysis for differentially expressed genes between KO^IEC and WT crypts. Ribosome and DNA replication pathways were enrichment in WT group. NES, normalized enrichment score; FDR, false discovery rate.