title: Coordinated shift of olfactory amino acid responses and V2R expression to an amphibian water nose during metamorphosis.
abstract: All olfactory receptors identified in teleost fish are expressed in a single sensory surface, whereas mammalian olfactory receptor gene families segregate into different olfactory organs, chief among them the main olfactory epithelium expressing ORs and TAARs, and the vomeronasal organ expressing V1Rs and V2Rs. A transitional stage is embodied by amphibians, with their vomeronasal organ expressing more 'modern', later diverging V2Rs, whereas more 'ancient', earlier diverging V2Rs are expressed in the main olfactory epithelium. During metamorphosis, the main olfactory epithelium of Xenopus tadpoles transforms into an air-filled cavity (principal cavity, air nose), whereas a newly formed cavity (middle cavity) takes over the function of a water nose. We report here that larval expression of ancient V2Rs is gradually lost from the main olfactory epithelium as it transforms into the air nose. Concomitantly, ancient v2r gene expression begins to appear in the basal layers of the newly forming water nose. We observe the same transition for responses to amino acid odorants, consistent with the hypothesis that amino acid responses may be mediated by V2R receptors.
authors.affiliation: Institute of Genetics, Biocenter, University of Cologne, Zülpicher Strasse 47a, 50674, Cologne, Germany.
authors.forename: Adnan S
authors.initials: AS
authors.lastname: Syed
authors.affiliation: Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.|Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Sansone
authors.affiliation: Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.|Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.|Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 38, 35392, Gießen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hassenklöver
authors.affiliation: Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.|Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.|Department of Animal Physiology and Molecular Biomedicine, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 38, 35392, Gießen, Germany.
authors.forename: Ivan
authors.initials: I
authors.lastname: Manzini
authors.affiliation: Institute of Genetics, Biocenter, University of Cologne, Zülpicher Strasse 47a, 50674, Cologne, Germany. sigrun.korsching@uni-koeln.de.
authors.forename: Sigrun I
authors.initials: SI
authors.lastname: Korsching
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000378:metabolism; D008297:Male; D008675:Metamorphosis, Biological / Q000235:genetics; D009297:Nasal Mucosa / Q000378:metabolism*; D009831:Olfactory Mucosa / Q000378:metabolism; D018034:Olfactory Receptor Neurons / Q000378:metabolism; D018035:Receptors, Odorant / Q000378:metabolism*; D015398:Signal Transduction; D012903:Smell; D019147:Vomeronasal Organ / Q000378:metabolism*; D014867:Water / Q000378:metabolism*; D014982:Xenopus laevis / Q000378:metabolism
chemical_list: D000596:Amino Acids; D018035:Receptors, Odorant; D014867:Water
keywords: Amino acid odorants; Calcium imaging; Evolution; Metamorphosis; Olfactory receptors; V2R family