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[en] Understanding the anatomical and genetic basis of complex phenotypic traits has long been a challenge for biological research. Domestic dogs offer a compelling model as they demonstrate more phenotypic variation than any other vertebrate species. Dogs have been intensely selected for specific traits and abilities, directly or indirectly, over the past 15,000 years since their initial domestication from the gray wolf. Because olfaction plays a central role in critical tasks, such as the detection of drugs, diseases, and explosives, as well as human rescue, we compared relative olfactory capacity across dog breeds and assessed changes to the canine olfactory system to their direct ancestors, wolves, and coyotes. We conducted a cross-disciplinary survey of olfactory anatomy, olfactory receptor (OR) gene variation, and OR gene expression in domestic dogs. Through comparisons to their closest wild canid relatives, the gray wolf and coyote, we show that domestic dogs might have lost functional OR genes commensurate with a documented reduction in nasal morphology as an outcome of the domestication process prior to breed formation. Critically, within domestic dogs alone, we found no genetic or morphological profile shared among functional or genealogical breed groupings, such as scent hounds, that might indicate evidence of any human-directed selection for enhanced olfaction. Instead, our results suggest that superior scent detection dogs likely owe their success to advantageous behavioral traits and training rather than an "olfactory edge" provided by morphology or genes.
Disciplines :
Zoology
Author, co-author :
Mouton, Alice ✱; Université de Liège - ULiège > Département des sciences et gestion de l'environnement (Arlon Campus Environnement) > Socio-économie, Environnement et Développement (SEED) ; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
Bird, Deborah J ✱; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
Li, Gang ✱; Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA ; College of Life Sciences, Shaanxi Normal University, Xi'an, China
Craven, Brent A ; Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA, USA
Levine, Jonathan M ; Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
Morselli, Marco ; Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, CA, USA
Pellegrini, Matteo ; Department of Molecular, Cell, and Developmental Biology, University of California at Los Angeles, CA, USA
Van Valkenburgh, Blaire ; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
Wayne, Robert K ; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
Murphy, William J ; Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
✱ These authors have contributed equally to this work.
Language :
English
Title :
Genetic and Anatomical Determinants of Olfaction in Dogs and Wild Canids.
NSF - National Science Foundation UCLA - University of California, Los Angeles
Funding text :
The authors thank curators and collection managers: M. Flannery of the California Academy of Sciences, C. Conroy of the Museum of Vertebrate Zoology, UC Berkeley, K. Molina of the Donald R. Dickey Collection, J. Dines of the Museum of Natural History Los Angeles County, K. Zyskowski of Yale Peabody Museum for providing skulls; M. Colbert, R. Ketchum, J. Maisano of the University of Texas HRCT Digital Morphology group, T. Jashaashvili, T. Skorka of Keck MIC, M. Faillace, J. Urbanski of General Electric Inspection Technologies, and T. Stecko, T. Ryan of Pennsylvania State University for producing high-quality CT scans. The authors thank Elizabeth Scanlan (TAMU) for domestic dog tissue sampling and preservation. This work was supported by National Science Foundation grants IOS-1457106 to R.K.W. and B.V.V. and IOS-1456506 to W.J.M. and J.M.L. A.M. and M.M. were supported by the QCBio Collaboratory Postdoctoral Fellowship (UCLA). A.M. used computational and storage services associated with the Hoffman2 Shared Cluster provided by UCLA Institute for Digital Research and Education\u2019s Research Technology Group.This work was supported by National Science Foundation grants IOS-1457106 to R.K.W. and B.V.V. and IOS-1456506 to W.J.M. and J.M.L. A.M. and M.M. were supported by the QCBio Collaboratory Postdoctoral Fellowship (UCLA). A.M. used computational and storage services associated with the Hoffman2 Shared Cluster provided by UCLA Institute for Digital Research and Education's Research Technology Group.
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