Figure 5.
Loss of CRAMP expression is associated with enhanced epithelial cell proliferation during postnatal development. Immunostaining for (A) lysozyme and (B) cryptdin 2 (red) in small intestinal tissue of 6-, 14-, and 21-d-old Cramp+/+ and Cramp−/− mice to demonstrate similar organ development. Bars, 25 μm. (C) Immunostaining for CRAMP (red) in the small intestinal tissue of 6-d-old as well as adult conventionally bred (left) and germ-free–bred (right) mice. Bar, 75 μm. (D) Immunostaining for CRAMP (red) in small intestinal tissue of 14-, 16-, and 18-d-old mice. Bar, 75 μm. (E) Immunostaining for the cell division marker Ki67 (red) in the small intestinal tissue of 1-, 6-, 14-, 21-, and 28-d-old mice illustrating the significant enhancement of epithelial proliferation in the intestinal crypts during the third week of life. MFP488 phalloidin (green) and DAPI (blue) were used as counterstaining. Bar, 75 μm.