Owing to their abundance of cutaneous glands, the skin of Amphibia is capable in maintaining homeostasis, serving as a desirable interface between the animal and its external surroundings. Distinct from other vertebrates, numerous dermal glands are functional in the amphibian skin, which help to regulate respiratory gas, salts, and water exchange, and contribute to the discharge of biochemical materials involved in antipredatory, antimicrobial and communication activities. Their skins, which were embedded with complex and active integumentary apparatuses, play a crucial role in the survival of this taxon. Secretions of the postaxillary gland are proteinaceous sexual pheromones, which are believed to attract females at male calling intermissions.Īs a transitional type of organism which emerged from aquatic environments to inhabit the terrestrial environment during animal evolution, amphibians’ adaptation to subaerial conditions is somewhat incomplete. Other than their extremely large size, SMGs structurally and histochemically resemble many reported specialized gland types in amphibian sexually dimorphic skin glands. pleuraden is a male-specific macrogland that consists primarily of SMGs, together with OSGs, I MGs and II MGs. On treatment with trypsin, this sexual attraction disappears. pleuraden exhibits chemotaxis toward homogenate of the postaxillary gland, but male does not. Lipid droplets, and organelles, such as rough endoplasmic reticulum and Golgi stacks, are located in the supranuclear cytoplasm of the mucocytes in SMG. Transmission electron microscopy reveals abundant secretory granules in SMG, which are biphasic, composed of an electron-opaque outer ring and a less electron-dense core. A discontinuous myoepithelial sheath lacking innervation encircles SMG mucocytes, and the outlets of such glands are X- or Y-shaped. SMGs are positive to periodic acid-Schiff stain and stained blue in Masson’s trichrome stain. The SMG is larger than other gland types, and consists of high columnar mucocytes with basal nuclei arranged radially toward a lumen. In addition to ordinary serous glands (OSG), type I and II mucous gland (I MG & II MG), a type of specialized mucous gland (SMG) is also found to constitute the postaxillary gland. The postaxillary gland has a thinner epidermis than the dorsal region of N. In the present study, we describe the structure and ultrastructure of the postaxillary gland, and explore its main function. Its biological function and its morphological and histochemical characteristics are unclear. The postaxillary gland is a sexually dimorphic macrogland in Nidirana pleuraden. Some macroglands are sexually dimorphic and mediate intersexual communication and reproductive success. These glands are distributed throughout the integument, but can accumulate in specific regions, forming visible outgrowths known as macroglands. The skin glands not only regulate water loss and respiratory gas and salt exchange, but are also involved in defense against predators and microorganisms, social communication, and reproduction. Stuck, Boris A.Owing to their incomplete adaptation to the terrestrial environment, amphibians possess complex cutaneous glandular systems. Rombaux, Philippe Sakagami, Masafumi Schaal, Benoist Shusterman, Dennis Small, Dana M. Meredith, Michael Miwa, Takaki Muttray, Axel Nordin, Steven Ogawa, Hisashi Philpott, Carl Rawson, Nancy E. Hummel, Cornelia Hummel, Thomas Just, Tino Kern, Robert C. Epstein, Joel Frasnelli, Johannes Freiherr, Jessica Grushka, Miriam Haehner, Antje Heckmann, Josef G. Abolmaali, Nasreddin Ching, Victor Damm, Michael Davidson, Terence M.
0 Comments
Leave a Reply. |