Figure 7. Ectopic NICD expression induced Paneth cells to proliferate and differentiate.

(A) Experimental scheme: Lyz1^CreER; R26R-NICD1-IRES-GFP mice were injected with tamoxifen, and sacrificed at 8, 24, 48, 72, and 168 hours for tissue analyses. Mice were labeled with EdU for 30 minutes before sacrifice.

(B-C) In non-tamoxifen treated mice, there was no GFP⁺/NICD⁺ cell detected (0 hour). After 8 hours GFP⁺ cells became readily detectable at crypt bottom, and the majority of GFP⁺ cells were EdU⁺. The number of EdU⁺GFP⁺ cells expanded at 24 hours, then reduced and disappeared from 48 hours onwards.

(D-E) Villus GFP⁺/NICD⁺ cells were detected approximately 1 day after the initial detection of GFP⁺ cells in the crypts. At 168 hours, GFP⁺/NICD⁺ cell was no longer observed suggesting a transient NICD-activated proliferation and differentiation. n.d. not detected.

(F) Villus GFP⁺NICD⁺ cells showed expression of enterocyte marker (SI) and goblet cell marker (Muc2). Scale bar, 10 μm.