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Fig. 4. (A) Transfection of C7 with claudin-2 cDNA. Western blots detecting
claudin-1 and claudin-2 in MDCK clones stably transfected with claudin-2 cDNA
(C7-cld-2), compared with control (transfected with vector alone, C7-vec). (B)
Decrease of Repi by introducing claudin-2 into MDCK-C7
cells. (C) Permeability of 4K FITC dextran in C7-vec and C7-cld-2. (D,E)
Comparison of claudin-2 expression in the different clones using a confocal
microscope. Detection of claudin-2 (red) and occludin (green) in C7-vec (D)
and in C7-cld-2 (E). Transfectants did not show detectable changes in
claudin-1 and -3 (not shown). F) Z-scans of C7-cld-2 detecting occludin
(green) and claudin-2 (red). Scans as shown on the right or above the top
views were performed in 200 nm steps over a range of 10 µm. A tight
junctional colocalization of claudin-2 with occludin is observed.