Morphology of the Intermandibular Gland of the Lesser Mouse Deer, Tragulus javanicus

The morphology of the intermandibular gland of the Lesser mouse deer (Tragulus javanicus), which plays an important function in marking area and territory and in the reproductive behaviour of the animal, was examined using immunohistochemistry, lectin histochemistry and scanning electron microscopy. The gland was composed of sebaceous and apocrine glandular material. Sebaceous glands occupied a greater area of the total gland and consisted of many large lobules with polyhedral cells having a pale cytoplasm. The sebaceous gland, being holocrine, possessed no special secretory ducts. The apocrine gland was lined by cuboid cells and the secretory products were often seen in the apical portions of the cells. Myoepithelial cells contained actin filaments lining the basal membranes of the apocrine gland and were surrounded by nerve fibres which immunostained with protein gene product 9.5. The secretion of the gland appears to be a mixture of larger amounts of lipid material from sebaceous glands, and glycoconjugates secreted by both sebaceous and apocrine glands. Lectin histochemistry detected these as galactose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, D-mannose and D-glucose. The male gland was larger in size and contained more N-acetyl galactosamine and N-acetyl glucosamine in its secretion than the gland of the female. This implied the presence of sexual differences in secretions in the intermandibular gland of the Lesser mouse deer.