Fig. 1.

Immunofluorescence labeling for the A subunit of vacuolar ATPase (V-ATPase) in mouse olfactory epithelium (OE). A: high levels of V-ATPase A-subunit expression in OE of a nondecalcified wild-type mouse pup, localized toward the apical pole of the cells (arrows). B: expression of significant levels of V-ATPase A subunit toward the apical pole of the secretory cells in Bowman's glands. C: V-ATPase A subunit staining in cells of the vomeronasal organ. D: expression pattern of A subunit of V-ATPase in OE of nondecalcified wild-type adult mouse similar to that of mouse pup, with predominantly apical localization of A subunit (arrows). In contrast to typical mouse pup, adult mouse OE additionally exhibits A-subunit staining localized to the lateral membrane in a cell subpopulation (arrowheads). Similar results were found in 15 mice (4 pups and 11 adults, both males and females). Scale bars, 30 μm.