Figure 3.

Presence of GGT1 or GGT7 in mouse and human olfactory epithelium

(A) Single-cell RNA-seq t-SNE plots and violin plots with overlaid log normalized expression levels of the Ggt1 and Ggt7 genes in the mouse nasal epithelium.

(B) Anti-GGT7 staining of a coronal section through a mouse nasal septum corresponding to the boxed area labeled “B” in Figure 1A mainly labels the apical surface of sustentacular cells (arrows), glands (arrowheads), and duct cells (open arrowheads) in OE. Scale bar = 50 μm.

(C) Immunofluorescent staining of the boundary between OE and RE corresponding to the boxed area labeled “C” in Figure 1A with antibodies against TUJ1 to label OSNs and CK19 to label respiratory cells shows anti-GGT7 labeling confined to sustentacular cells (arrows) in OE. Scale bar = 25 μm.

(D) Relative mRNA expression of Ggt7 and Ggt1 in mouse OE and RE. The data are shown as the mean ± SEM (n = 4). ∗p < 0.05.

(E) Immunofluorescent staining of OE from an OMP-tTA; TetO-DTA transgenic mouse from the boxed areas labeled “G-I” in Figure 1F illustrates the selective staining of anti-GGT7 for neuronal OE. The neuronal OE contains TUJ1(+) OSNs as well as GGT7(+) sustentacular cells (arrows) and glands (arrowheads). The aneuronal OE lacks staining with TUJ1, TUBB4, and GGT7. Areas of respiratory metaplasia contain TUBB4(+) respiratory cells but lack TUJ1 and GGT7 staining. Scale bar = 25 μm.

(F) Sections of human autopsy samples corresponding with boxed areas labeled “K-M” in Figure 1J are labeled with anti-GGT7. The neuronal OE contains TUJ1(+) OSNs as well as GGT7(+) sustentacular cells (arrows). The aneuronal OE lacks TUJ1, TUBB4, and GGT7 staining. Respiratory metaplastic epitlelium consists of TUBB4 positive cells but lacks TUJ1 and GGT7 staining. Scale bar = 25 μm.

(G) Single-cell RNA-seq t-SNE and violin plots with expression levels of the GGT7 gene in the human nasal epithelium.