Fig 2: Immunohistochemical localization of OMP and GAP-43 in the cattle OM. The adult receptor cells in the middle region of the OE are positive for OMP in neonates (A) and adults (B), and the dendritic processes of OMP-positive cells reach the free mucosal border at both ages. The immature receptor cells in the basal region of OE are positive for GAP-43 in neonates (C) and adults (D), and some dendritic processes are positive for GAP-43 at both ages. OMP and GAP-43 are also expressed in the nerve bundle. Counterstained with hematoxylin. Scale bars = 50 µm.OMP, olfactory marker protein; GAP-43, growth associated protein-43; OM, olfactory mucosa; OE, olfactory epithelium; NB, nerve bundle; OBC, olfactory basal cells; OSC, olfactory supporting cells; ORC, olfactory receptor cells.

Fig 3: Schematic of the OM employed in this study and histological characteristics of the cattle OM. Schematic shows the location of the OM sampling in the nasal cavity of Korean native cattle (A). Transverse sections of the OM of neonates (B) and adults (C) stained with hematoxylin and eosin. High-magnification views of the Bowman’s glandular acini of neonates (D and E) and adults (F and G), stained with PAS (D and F) and Alcian blue (pH 2.5) (E and G), respectively. Scale bars in A and B = 50 µm. Scale bars in C–F = 25 µm.OM, olfactory mucosa; BD, Bowman’s glandular duct; BG, Bowman’s gland; NB, nerve bundle; OBC, olfactory basal cells; OSC, olfactory supporting cells; ORC, olfactory receptor cells.