Figure 1

TRPM5 promoter-driven GFP expression in microvillous cells of the olfactory epithelium. Top left inset: a draw of a hemi-nose. The blue area corresponds to the image of A. OB: olfactory bulb. A. An epi-fluorescence image from a hemi-nose preparation showing GFP expression in the MOE. B. A confocal image from an endo-turbinate epithelial strip showing that the GFP-expressing cells were scattered and had a pear- or flask-like shape. C. The GFP-expressing cells lie in the most superficial layer of the MOE. Arrow head points to a microvillous cell. In contrast, the GFP-expressing OSNs show apical dendrites and axons (arrows) that form olfactory nerve bundles. D-I. Representative images of GFP-expressing microvillous cells showing various cell shapes and apical processes. Insets showed apical microvilli with heightened intensity, which could be wavy (D), branched (E), stiff and spreading (F and G), short brush-like (H), or relatively fine (I). These cells did not have axons although some cells showed short basal processes (arrows in E and I). J. A rare type of microvillous cells with a relatively thick and longer basal process extending half of the epithelium. Scales: A, 500 μm; B, C and J, 20 μm; D to I, 5 μm.