Histological and Ultrastructural Characteristics of the Primordial Vomeronasal Organ in Lungfish
- 23 January 2012
- journal article
- research article
- Published by Wiley in The Anatomical Record
- Vol. 295 (3), 481-491
- https://doi.org/10.1002/ar.22415
Abstract
Many vertebrates have two anatomically distinct olfactory organs—the olfactory epithelium and the vomeronasal organ—to detect chemicals such as general odorants and pheromones in their environment. The vomeronasal organ is not present in fish but is present in vertebrates of a higher order than amphibians. Among all extant fishes, the lungfish is considered to be genetically and phylogenetically closest to tetrapods. In this study, we examined the olfactory organs of African lungfish, Protopterus annectens, by lectin histochemistry, immunohistochemistry, and transmission electron microscopy. Two types of sensory epithelia were identified in the olfactory organ—the olfactory epithelium covering the surface of lamellae and the sensory epithelium lining the recesses both at the base of lamellae and in the wall of the nasal sac—and designated here as the lamellar olfactory epithelium and the recess epithelium, respectively. Based on analysis of G‐protein expression and ultrastructure, the lamellar olfactory epithelium resembled the olfactory epithelium of ordinary teleosts and the recess epithelium resembled the vomeronasal organ of tetrapods. Furthermore, lectin histochemistry demonstrated that the axons from the recess epithelium converge and project to the ventrolateral part of the olfactory bulb, suggesting that lungfish possess a region homologous to the accessory olfactory bulb of tetrapods. Based on these results, it seems appropriate to refer to the recess epithelium as “a primordium of the vomeronasal organ.” This study may provide important clues to elucidate how the vomeronasal organ emerged during the evolution of vertebrates. Anat Rec, 2012.Keywords
This publication has 43 references indexed in Scilit:
- Cladistic Analysis of Olfactory and Vomeronasal SystemsFrontiers in Neuroanatomy, 2011
- Lungfishes, like tetrapods, possess a vomeronasal systemFrontiers in Neuroanatomy, 2010
- Xenopus V1R Vomeronasal Receptor Family Is Expressed in the Main Olfactory SystemChemical Senses, 2008
- Diversity in the olfactory epithelium of bony fishes: Development, lamellar arrangement, sensory neuron cell types and transduction componentsJournal of Neurocytology, 2005
- The terminal nerve and its relation with extrabulbar “olfactory” projections: Lessons from lampreys and lungfishesMicroscopy Research and Technique, 2004
- Lectin-Binding Patterns in the Olfactory Epithelium and Vomeronasal Organ of the Common Marmoset.The Journal of Veterinary Medical Science, 1998
- Phylogeny of the vomeronasal system and of receptor cell types in the olfactory and vomeronasal epithelia of vertebratesMicroscopy Research and Technique, 1992
- A novel multigene family may encode odorant receptors: A molecular basis for odor recognitionCell, 1991
- Etude ultrastructurale de la région apicale des cellules de l'épithélium olfactif de Protopterus annectens owen (dipneustes)Journal of Ultrastructure Research, 1979
- Ultrastructure of the Olfactory Epithelium in the Australian LungfishNeoceratodus forsteriActa Zoologica, 1972