Morphological Structure of Vomeronasal Organ in Akkaraman, Morkaraman, and Tuj Sheep

This study examined the vomeronasal organs (VNOs) obtained from the heads of two Akkaraman sheep, two Morkaraman sheep and four Tuj sheep. The animals studied were female and 1.5 years old. The aim of this study was to describe the anatomical and histochemical features of the VNO in Akkaraman, Morkaraman, and Tuj sheep breeds. It was determined that the VNO was oval-shaped and tubular in these breeds. In general, the right VNO was longer in all three breeds of sheep. In the cranial sections of the VNO, which is located in the form of a pair of blind tubes at the base of the nasal septum, the entire epithelial layer is rostrally lined with non-sensory epithelium. However, moving caudally, sensory epithelium begins to appear along the medial wall of the VNO. The caudal sections of the VNO had no serous vomeronasal glands. A small number of mucous glands were observed within the lamina propria of the VNO. The VNO of the Akkaraman sheep was found to have more mucous glands than those of the other two breeds of sheep. While the hyaline VN cartilage surrounding the lamina propria was intact rostrally, it was observed that the cartilage opened in the dorsal region. The ring structure was disrupted and the cartilage adopted a J-shape. As it moved caudally, the cartilage closed again from the dorsolateral region. In conclusion, the goblet cells in the non-sensory pseudostratified columnar epithelial tissue located in the lateral lamina epithelialis of the VNO showed strong PAS (+) and AB (-) staining characteristics. While the VN glands were generally considered serous, it was observed that most gland cells showed strong PAS (+) staining characteristics, while a few were weak AB (+) and most were AB (-). Mucous glands, which were fewer in number, were negative for both PAS (-) and AB (-). Both PAS and AB staining showed positive (+) staining characteristics for the VN cartilage. In conclusion, the anatomical and histological structure of the VNO in Akkaraman, Morkaraman, and Tuj sheep was examined and compared with findings from other studies on this subject in different animal species.