Immunohistochemical staining of VNOs from Korean native cattle. (A–D) PGP9.5 is intensely labeled in receptor cells in the VSE of both neonates (A) and adults (C), and some nerve fibers and ciliated cells also showed reactions in the VNSE of neonates (B) and adults (D). PGP9.5 is also expressed in the vomeronasal nerve bundle (A, C; asterisks). (E–H) OMP is weakly labeled in the VSE of neonates (C) and adults (G), and some ciliated cells showed reactions in VNSE of neonates (D) and adults (H). Counterstained with hematoxylin. OMP, olfactory marker protein; PGP9.5, protein gene product9.5; VNSE, vomeronasal non-sensory epithelium; VSE, vomeronasal sensory epithelium. Scale bars = 50 μm.