Dietary cystine restriction increases the expression of stem cell markers and proliferation specifically in small intestine.

qRT-PCR gene expression in A) small intestine and B) colon of markers of intestinal stem cell (Lgr5, Sox9, Olfm4), proliferative cells (Ki67), enterocyte (Krt20), Paneth cell (Lyz) and goblet cells (Muc2) normalized for normal cys (n = 8/group, mean ± SEM, multiple Mann-Whitney tests, *p<0.05). C) (Left) Representative images of Ki67 immunohistochemistry on small intestinal crypts (scale bar = 50 μm). Arrows indicate length of proliferative zone. (Top Right) Quantification of integrated density of Ki67 corrected for haematoxylin, as measured using Fiji, of multiple crypts per mouse. Each column represents one mouse (n = 5 for normal cys, n = 3 for low cys, unpaired t-test, *p<0.05). (Bottom Right) Quantification of the length of the proliferative zone, using the length tool in Fiji, stained by Ki67 of multiple crypts per mouse. Each column represents one mouse (n = 5 for normal cys, n = 3 for low cys, unpaired t-test, *p<0.05).