Figure 4. Localization of Mel1a and Mel1c in progressive confocal optical slices of Xenopus corneal epithelium. A: Image of the most superficial surface of the surface corneal epithelium. Note that only the red Mel1a immunoreactivity is present on the lateral membranes. B-F: As the 0.4 µm slices progress deeper into the corneal epithelium layer, the Mel1a immunoreactivity lessens, whereas the green Mel1c immunoreactivity increases (note arrowheads indicating an example of this), indicating that the Mel1c receptor is located basal to the Mel1a receptor. Nuclei are stained with DAPI. The magnification bar (F) represents 20 µm.