Figure 8. Localization of ZO-1 and Mel1a in progressive confocal optical slices of Xenopus corneal epithelium. A: Image of the most superficial surface of the surface corneal epithelium. In the most apical slice (slice 0.0 µm), red Mel1a, green ZO-1, and merged yellow labeling is observed in variable amounts on different cell membranes. B-F: As the 0.4-µm slices progress deeper into the corneal epithelium layer, the green ZO-1 immunoreactivity gradually lessens, whereas the red Mel1a immunoreactivity increases (note arrowheads indicating an example of this), indicating that the Mel1a receptor is located basal to the zonula adherens, but is in very close proximity in most of the slices (A-C). Nuclei are stained with DAPI. The magnification bar (F) represents 20 µm.