Fig. 7. Tg737^orpk mutant mice demonstrate no overt loss of epithelial polarity in the choroid plexus. Arrowheads indicate the apical surface of the choroid plexus. (A) Expression of -catenin (red) in sections of wild-type and mutant mice. (B) ZO-1 (red) is localized to the tight junctional complexes near the apical surface of wild-type and mutant choroid epithelia. (C) Analysis of transport proteins Na⁺/K⁺ATPase (green) and the anion exchanger type 2 (AE2, red) shows normal localization at the apical and basolateral membranes, respectively. Scale bar: 20 µm.