Fig. 2. Expression of Tau-reporters mimic endogenous O/E pattern. (A,C) Mid-sagittal view of an adult O/E2 heterozygous animal after X-gal staining. ß-galactosidase activity was present in the olfactory epithelium and bulb (A), vomeronasal organ (C) and axon fibers projecting from these two structures. (B,D) Mid-sagittal view of an adult O/E3 heterozygous animal. GFP fluorescence was visible in the olfactory epithelium and bulb (B), vomeronasal organ (D), and axon fibers projecting from these two structures. (E) X-gal staining of olfactory epithelium section of an O/E2^lacZ/lacZ animal showing ß-gal activity in the ORN cell bodies and axon bundles. (F) X-gal staining of OB section of O/E2^lacZ/+ animal showing ß-gal activity in ORN axons projecting to the olfactory glomeruli. (G) An olfactory epithelium section of an O/E3^GFP/+ animal showing GFP fluorescence in the ORN cell bodies and axon bundles. (H) An OB section of O/E3^GFP/+ animal showing GFP fluorescence in ORN axons projecting to the olfactory glomeruli. (I,J) Whole-mount X-gal staining of an E11 O/E2^lacZ/+ mouse embryo showing ß-gal expression in the neural tissues. (K) Two-color confocal image of OE from heterozygous OE3 mouse. Intrinsic GFP localization is shown in green and neuronal specific tubulin shown in red. Two cells near the basal lamina that express only the GFP reporter are indicated by arrows.