QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 6. Fate of Notch1-activated cells in the intestinal lineages. (A) N1::cre is not activated in the embryonic gut at E14.5. (B,C) Abundant activity of N1::cre in the adult duodenum labels the complete crypt-villus axis. Within blue crypts, all cells appear labeled, suggesting monoclonality (B), but polyclonal villi show alternating patterns of Notch1 activity (C). (D-G) Immuno identification of N1::cre descendents as enterocytes by alkaline phosphatase activity (D), goblet cells by PAS staining (E), endocrine cells by synaptophysin staining (F, inset), and Paneth cells by lysozyme staining (G, arrowhead). (H) Infrequent labeling of single goblet cells (arrowhead) suggests Notch1 signaling may also occur in (committed) differentiated intestinal epithelium. (I) -VLLS staining identifies Notch1 signaling in crypt progenitors (black arrowhead) and in a few scattered goblet cells (white arrowheads) within the villus (see also Fig. S5J in the supplementary material). Notch1 -VLLS staining is nuclear; the precipitate in the cytoplasm of goblet cells may be an artifact. (J) Notch1 is expressed in spontaneous adenomas from Apc^min/+ mice (arrowhead) and in adenomas from Apc^min/+:N1::cre mice, indicating Notch1 activation in cells sustaining Apc mutation. (K) The normal villus epithelium does not express Notch1 but N1::cre marks this lineage (arrowhead). (L) Notch1-deficient ES cells contribute efficiently to the adult intestinal epithelium of chimeric mice; they preferentially differentiate towards the secretory lineages at the expense of enterocytes. Note the significant increase in mucinproducing goblet cells in X-Gal-stained villi and crypts compared with unstained wild-type intestine. (M) Control Notch1 wild-type R26-lacZ chimeric intestines show no preference to differentiate towards the secretory lineages. (N,O) Quantitation of the differentiation defect observed in Notch1-deficient intestines by combining immunohistochemical staining for differentiated cell types with X-Gal staining to identify Notch1-deficient cells, expressed as absolute numbers with s.d. (N) and as a ratio of Notch1-knockout/Notch1-proficient to wild type (O). Note significant increase in all secretory lineages in the absence of Notch1 at the expense of enterocytes. The intestines of mice composed of wild-type R26-lacZ cells showed a normal contribution and no defects (not shown). Magnification: A, 4x; B-G,J-M,20x; H,I, 40x.

Return to article