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The vomeronasal organ of the tammar wallaby
Author(s) -
Schneider Nanette Y.,
Fletcher Terence P.,
Shaw Geoff,
Renfree Marilyn B.
Publication year - 2008
Publication title -
journal of anatomy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 118
eISSN - 1469-7580
pISSN - 0021-8782
DOI - 10.1111/j.1469-7580.2008.00933.x
Subject(s) - vomeronasal organ , tammar wallaby , biology , apocrine , marsupial , anatomy , nasal glands , ovulation , cilium , olfactory system , endocrinology , microbiology and biotechnology , hormone , neuroscience , zoology , mucous membrane of nose
Abstract The vomeronasal organ is the primary olfactory organ that detects sexual pheromones in mammals. We investigated the anatomy of the vomeronasal organ of the tammar wallaby ( Macropus eugenii ), a small macropodid marsupial. Pheromones may be important for activation of the hypothalamo‐pituitary axis of tammar males at the start of the breeding season because plasma testosterone and luteinizing hormone concentration in males rise concurrently with pregnancy and the post‐partum ovulation in females. The gross anatomy and the connection to the brain of the vomeronasal organ were examined by light and electron microscopy in adult male and female tammars. The vomeronasal organ was well developed in both sexes. The vomeronasal organ is a tubular organ connected at the rostral end via the nasopalatine duct (incisive duct) to the mouth and nasal cavity. At the rostral end the lumen of the vomeronasal organ was crescent shaped, changing to a narrow oval shape caudally. Glandular tissue associated with the vomeronasal organ increased towards the blind end of the organ. The tammar has the typical pattern of mammalian vomeronasal organs with electron‐dense supporting cells and electron‐lucent receptor cells. Microvilli were present on the surface of both epithelia while cilia were only found on the surface of the non‐receptor epithelium. Some non‐receptor epithelial cells appeared to secrete mucus into the vomeronasal organ lumen. The vomeronasal organ shows a high degree of structural conservation compared with eutherian mammals. The degree of vomeronasal organ development makes it likely that, as in other mammals, pheromones are important in the reproduction of the tammar.