Differentiation block in CEABAC mouse colonic epithelium at 3 weeks of age.

<p>A) Mucin staining of colonic crypts of WT, CEABAC2, CEABAC10, and CEABAC20 mice shows a progressively decreasing number of visible purplish-colored differentiated goblet cells (indicated by an arrow in the WT colonic crypt) correlated with increasing CEABAC transgene copy number. Lengthening of crypts, poor cryptal alignment, increase of peri-cryptal stroma, absence of bluish cytoplasm, abundance of small purplish mucinous vacuoles and elongation of nuclei are noted in CEABAC20 mice, indicating hyperplastic changes. Magnification: 400×. Staining: AB/PAS/MG. B) Number of normal-size goblet cells per crypt plotted against transgene copy-number; each data point is significantly different from the others (<i>P</i><0.0001). 35%, 67% and 85% (95% after considering the 3-fold increase in crypt length) reductions relative to WT mice (i.e. 0 transgene copy) are obtained for CEABAC2, CEABAC10 and CEABAC20 mice, respectively. Error bars represent standard errors of the mean (N = 9). WT denotes wild-type littermate.