Fig. 3.

Immunofluorescence staining of distal colon shows the dramatic loss of DRA in K8^−/−, but not in K8^+/− mice. Distal colon cryosections fixed with 4% paraformaldehyde in PBS for 15 min at room temperature were stained with DRA. The results show absence of DRA in K8^−/− mice (C) compared with normal DRA staining in K8^+/+ mice (A). K8^+/− mice showed patchy DRA staining (B). DRA was abolished in the K8^−/− distal colon apical membrane compared with K8^+/− and K8^+/+ mice, whereas apical villin was normally distributed. DAPI was used to stain nuclei. Scale bar 100 μm.