Fig. 6: NPY1R-expressing colon cells are self-renewing, multipotent stem cells in vivo.

a, Npy1r-eGFP-IRES-CreERT2 mice were bred with a Rosa26-LSL-tdTom mouse line. b, Mice were injected with 4 mg tamoxifen per 30 g bodyweight and harvested at 24 h (n = 3), 1 week (n = 3) or 1 month (n = 3) after injection. At 24 h, an RFP signal was detected in the epithelium of the proximal colon (see magnified insert). RFP was detected at the base of the crypt of the middle and distal colon, as well as the rectum. 1 week after induction, the RFP signal was lost in the proximal colon, whereas it spread from the base of the crypt in the middle and distal colon and the rectum. At 1 month, only the middle colon (at a lower frequency), distal colon and rectal crypts retained the RFP signal. c, Mice were injected with 3 mg tamoxifen per 30 g bodyweight and harvested after 1 month (n = 3). Co-IF of RFP and the lineage markers MUC2, CHGA and DRA showed that all RFP⁺ traced units expressed major lineage markers. Scale bars, 25 μm.