Extended Data Fig. 9: Nox1 CreERT2-driven Apc deletion in the intestine generates mild hyperplasia only in crypts adjacent to Peyer’s patches.
From: NOX1 and NPY1R mark regional colon stem cell populations that serve as cancer origins in vivo
a) Nox1-2A-CreERT2, APCfl/fl 5-month old mice were harvested and stained for RFP and β-catenin in all the digestive tissues expressing Nox1 to evaluate any potential Cre recombinase expression leakage (n = 3); b) Mice were injected twice at 2-days interval with 4 mg/30 g body weight of tamoxifen and the small intestine harvested after 1 month. β-catenin IHC showed nucleocytoplasmic accumulation only in the crypts directly adjacent to Peyer’s patches but absent from the ileum (n = 4); c) Co-IF of β-catenin with Ki67 showed that these hyperplastic crypts were proliferative (n = 4); d) Nox1-2A-CreERT2, APCfl/fl mice were bred with LSL- KrasG12D mice. Mice were induced with 1 mg of tamoxifen per 30 g of body weight and harvested after 1 month. No β-catenin accumulation was detected in the ileum and Peyer’s patch epithelium and hyperactivation of pMapk was found as expected in the CBC and TA cells (n = 3). Scale bar: 250μm (a, upper panel), 50μm (a, lower panel), and 25μm (b-d).
