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Silva Teixeira CS, Cerqueira NMFSA, Silva Ferreira AC. Unravelling the Olfactory Sense: From the Gene to Odor Perception. Chem Senses 2015; 41:105-21. [PMID: 26688501 DOI: 10.1093/chemse/bjv075] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although neglected by science for a long time, the olfactory sense is now the focus of a panoply of studies that bring new insights and raises interesting questions regarding its functioning. The importance in the clarification of this process is of interest for science, but also motivated by the food and perfume industries boosted by a consumer society with increasingly demands for higher quality standards. In this review, a general overview of the state of art of science regarding the olfactory sense is presented with the main focus on the peripheral olfactory system. Special emphasis will be given to the deorphanization of the olfactory receptors (ORs), a critical issue because the specificity and functional properties of about 90% of human ORs remain unknown mainly due to the difficulties associated with the functional expression of ORs in high yields.
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Affiliation(s)
- Carla S Silva Teixeira
- Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal
| | - Nuno M F S A Cerqueira
- UCIBIO@Requimte/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal and
| | - António C Silva Ferreira
- Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal, Department of Viticulture and Oenology, Institute for Wine Biotechnology, University of Stellenbosch, Private Bag XI, Matieland 7602, South Africa
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52
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Wallrabenstein I, Singer M, Panten J, Hatt H, Gisselmann G. Timberol® Inhibits TAAR5-Mediated Responses to Trimethylamine and Influences the Olfactory Threshold in Humans. PLoS One 2015; 10:e0144704. [PMID: 26684881 PMCID: PMC4684214 DOI: 10.1371/journal.pone.0144704] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 11/23/2015] [Indexed: 11/25/2022] Open
Abstract
In mice, trace amine-associated receptors (TAARs) are interspersed in the olfactory epithelium and constitute a chemosensory subsystem that is highly specific for detecting volatile amines. Humans possess six putative functional TAAR genes. Human TAAR5 (hTAAR5) is highly expressed in the olfactory mucosa and was shown to be specifically activated by trimethylamine. In this study, we were challenged to uncover an effective blocker substance for trimethylamine-induced hTAAR5 activation. To monitor blocking effects, we recombinantly expressed hTAAR5 and employed a commonly used Cre-luciferase reporter gene assay. Among all tested potential blocker substances, Timberol®, an amber-woody fragrance, is able to inhibit the trimethylamine-induced hTAAR5 activation up to 96%. Moreover, human psychophysical data showed that the presence of Timberol® increases the olfactory detection threshold for the characteristic fishy odor of trimethylamine by almost one order of magnitude. In conclusion, our results show that among tested receptors Timberol® is a specific and potent antagonist for the hTAAR5-mediated response to trimethylamine in a heterologous system. Furthermore, our data concerning the observed shift of the olfactory detection threshold in vivo implicate that hTAAR5 or other receptors that may be inhibited by Timberol® could be involved in the high affinity olfactory perception of trimethylamine in humans.
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Affiliation(s)
| | | | | | - Hanns Hatt
- Department of Cell Physiology, Ruhr-University Bochum, Bochum, Germany
| | - Günter Gisselmann
- Department of Cell Physiology, Ruhr-University Bochum, Bochum, Germany
- * E-mail:
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53
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Millar Vernetti P, Rossi M, Cerquetti D, Perez Lloret S, Merello M. Comparison of Olfactory Identification Patterns among Parkinson’s Disease Patients from Different Countries. Chem Senses 2015; 41:77-83. [DOI: 10.1093/chemse/bjv062] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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54
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Cueno ME, Ochiai K. Re-discovering periodontal butyric acid: New insights on an old metabolite. Microb Pathog 2015; 94:48-53. [PMID: 26466516 DOI: 10.1016/j.micpath.2015.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 10/05/2015] [Accepted: 10/06/2015] [Indexed: 02/02/2023]
Abstract
The oral microbiome is composed of detrimental and beneficial microbial communities producing several microbial factors that could contribute to the development of the oral microbiome and, likewise, may lead to the development of host diseases. Metabolites, like short-chain fatty acids, are commonly produced by the oral microbiome and serve various functions. Among the periodontal short-chain fatty acids, butyric acid is mainly produced by periodontopathic bacteria and, attributable to the butyrate paradox, is postulated to exhibit a dual function depending on butyric acid concentration. A better understanding of the interconnecting networks that would influence butyric acid function in the oral cavity may shed a new light on the current existing knowledge and view regarding butyric acid.
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Affiliation(s)
- Marni E Cueno
- Department of Microbiology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
| | - Kuniyasu Ochiai
- Department of Microbiology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
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55
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Jiang Y, Gong NN, Hu XS, Ni MJ, Pasi R, Matsunami H. Molecular profiling of activated olfactory neurons identifies odorant receptors for odors in vivo. Nat Neurosci 2015; 18:1446-54. [PMID: 26322927 PMCID: PMC4583814 DOI: 10.1038/nn.4104] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/09/2015] [Indexed: 12/15/2022]
Abstract
The mammalian olfactory system uses a large family of odorant receptors (ORs) to detect and discriminate amongst a myriad of volatile odor molecules. Understanding odor coding requires comprehensive mapping between ORs and corresponding odors. We developed a means of high-throughput in vivo identification of OR repertoires responding to odorants using phosphorylated ribosome immunoprecipitation of mRNA from olfactory epithelium of odor-stimulated mice followed by RNA-Seq. This approach screened the endogenously expressed ORs against an odor in one set of experiments using awake and freely behaving mice. In combination with validations in a heterologous system, we identified sets of ORs for two odorants, acetophenone and 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), encompassing 69 OR-odorant pairs. We also identified shared amino acid residues specific to the acetophenone or TMT receptors and developed models to predict receptor activation by acetophenone. Our results provide a method for understanding the combinatorial coding of odors in vivo.
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Affiliation(s)
- Yue Jiang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,University Program in Genetics and Genomics, Duke University Medical Center, Durham, North Carolina, USA.,Department of Statistical Science, Duke University, Durham, North Carolina, USA
| | - Naihua Natalie Gong
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Xiaoyang Serene Hu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Mengjue Jessica Ni
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Radhika Pasi
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, North Carolina, USA
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56
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Hayden S, Teeling EC. The molecular biology of vertebrate olfaction. Anat Rec (Hoboken) 2015; 297:2216-26. [PMID: 25312375 DOI: 10.1002/ar.23031] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 06/25/2014] [Indexed: 01/16/2023]
Abstract
The importance of chemosensation for vertebrates is reflected in the vast and variable nature of their chemosensory tissues, neurons, and genes, which we explore in this review. Immense progress has been made in elucidating the molecular biology of olfaction since the discovery of the olfactory receptor genes by Buck and Axel, which eventually won the authors the Nobel Prize. In particular, research linking odor ligands to olfactory receptors (ORs) is truly revolutionizing our understanding of how a large but limited number of chemosensory receptors can allow us to perceive the massive diversity of odors in our habitat. This research is providing insight into the evolution of genomes and providing the raw data needed to explore links between genotype and phenotype, still a grand challenge in biology. Research into olfaction is still developing and will no doubt continue until we have a clear understanding of how all odors are detected and the evolutionary forces that have molded the chemosensory subgenome in vertebrates. This knowledge will not only be a huge step in elucidating olfactory function, advancing scientific knowledge and techniques, but there are also commercial applications for this research. This review focuses on the molecular basis of chemosensation, particularly olfaction, its evolution across vertebrates and the recent molecular advances linking odors to their cognate receptors.
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Affiliation(s)
- Sara Hayden
- Department of Biochemistry, University of Washington, Seattle, Washington
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57
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Individual olfactory perception reveals meaningful nonolfactory genetic information. Proc Natl Acad Sci U S A 2015; 112:8750-5. [PMID: 26100865 DOI: 10.1073/pnas.1424826112] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Each person expresses a potentially unique subset of ∼ 400 different olfactory receptor subtypes. Given that the receptors we express partially determine the odors we smell, it follows that each person may have a unique nose; to capture this, we devised a sensitive test of olfactory perception we termed the "olfactory fingerprint." Olfactory fingerprints relied on matrices of perceived odorant similarity derived from descriptors applied to the odorants. We initially fingerprinted 89 individuals using 28 odors and 54 descriptors. We found that each person had a unique olfactory fingerprint (P < 10(-10)), which was odor specific but descriptor independent. We could identify individuals from this pool using randomly selected sets of 7 odors and 11 descriptors alone. Extrapolating from this data, we determined that using 34 odors and 35 descriptors we could individually identify each of the 7 billion people on earth. Olfactory perception, however, fluctuates over time, calling into question our proposed perceptual readout of presumably stable genetic makeup. To test whether fingerprints remain informative despite this temporal fluctuation, building on the linkage between olfactory receptors and HLA, we hypothesized that olfactory perception may relate to HLA. We obtained olfactory fingerprints and HLA typing for 130 individuals, and found that olfactory fingerprint matching using only four odorants was significantly related to HLA matching (P < 10(-4)), such that olfactory fingerprints can save 32% of HLA tests in a population screen (P < 10(-6)). In conclusion, a precise measure of olfactory perception reveals meaningful nonolfactory genetic information.
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58
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de March CA, Ryu S, Sicard G, Moon C, Golebiowski J. Structure-odour relationships reviewed in the postgenomic era. FLAVOUR FRAG J 2015. [DOI: 10.1002/ffj.3249] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Claire A. de March
- Institut de Chimie de Nice; Université Nice Sophia Antipolis; UMR CNRS 7272, parc Valrose 06108 Nice cedex 02 France
| | - SangEun Ryu
- Laboratory of Chemical Senses, Department of Brain and Cognitive Science; DGIST (Daegu Gyeongbuk Institute of Science & Technology); 50-1 Sang-Ri, Hyeonpung-Myeon, Dalseong-Gun Daegu 711-873 Korea
| | - Gilles Sicard
- Neurobiology of Cellular Interactions and Neurophysiopathology; Aix-Marseille Université; UMR CNRS 7259 13331 Marseille cedex 03 France
| | - Cheil Moon
- Laboratory of Chemical Senses, Department of Brain and Cognitive Science; DGIST (Daegu Gyeongbuk Institute of Science & Technology); 50-1 Sang-Ri, Hyeonpung-Myeon, Dalseong-Gun Daegu 711-873 Korea
| | - Jérôme Golebiowski
- Institut de Chimie de Nice; Université Nice Sophia Antipolis; UMR CNRS 7272, parc Valrose 06108 Nice cedex 02 France
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59
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Block E, Jang S, Matsunami H, Sekharan S, Dethier B, Ertem MZ, Gundala S, Pan Y, Li S, Li Z, Lodge SN, Ozbil M, Jiang H, Penalba SF, Batista VS, Zhuang H. Implausibility of the vibrational theory of olfaction. Proc Natl Acad Sci U S A 2015; 112:E2766-74. [PMID: 25901328 PMCID: PMC4450420 DOI: 10.1073/pnas.1503054112] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The vibrational theory of olfaction assumes that electron transfer occurs across odorants at the active sites of odorant receptors (ORs), serving as a sensitive measure of odorant vibrational frequencies, ultimately leading to olfactory perception. A previous study reported that human subjects differentiated hydrogen/deuterium isotopomers (isomers with isotopic atoms) of the musk compound cyclopentadecanone as evidence supporting the theory. Here, we find no evidence for such differentiation at the molecular level. In fact, we find that the human musk-recognizing receptor, OR5AN1, identified using a heterologous OR expression system and robustly responding to cyclopentadecanone and muscone, fails to distinguish isotopomers of these compounds in vitro. Furthermore, the mouse (methylthio)methanethiol-recognizing receptor, MOR244-3, as well as other selected human and mouse ORs, responded similarly to normal, deuterated, and (13)C isotopomers of their respective ligands, paralleling our results with the musk receptor OR5AN1. These findings suggest that the proposed vibration theory does not apply to the human musk receptor OR5AN1, mouse thiol receptor MOR244-3, or other ORs examined. Also, contrary to the vibration theory predictions, muscone-d30 lacks the 1,380- to 1,550-cm(-1) IR bands claimed to be essential for musk odor. Furthermore, our theoretical analysis shows that the proposed electron transfer mechanism of the vibrational frequencies of odorants could be easily suppressed by quantum effects of nonodorant molecular vibrational modes. These and other concerns about electron transfer at ORs, together with our extensive experimental data, argue against the plausibility of the vibration theory.
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Affiliation(s)
- Eric Block
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222;
| | - Seogjoo Jang
- Department of Chemistry and Biochemistry, Queens College, and Graduate Center, City University of New York, Flushing, NY 11367;
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology and Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 27710;
| | | | - Bérénice Dethier
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222
| | - Mehmed Z Ertem
- Department of Chemistry, Yale University, New Haven, CT 06520; Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973
| | - Sivaji Gundala
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222
| | - Yi Pan
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China; and
| | - Shengju Li
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China; and
| | - Zhen Li
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China; and
| | - Stephene N Lodge
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222
| | - Mehmet Ozbil
- Department of Chemistry, Yale University, New Haven, CT 06520
| | - Huihong Jiang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China; and
| | - Sonia F Penalba
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222
| | | | - Hanyi Zhuang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China; and Institute of Health Sciences, Shanghai Jiao tong University School of Medicine/Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences, Shanghai 200031, China
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60
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Armelin-Correa LM, Nagai MH, Leme Silva AG, Malnic B. Nuclear architecture and gene silencing in olfactory sensory neurons. BIOARCHITECTURE 2015; 4:160-3. [PMID: 25714005 DOI: 10.4161/19490992.2014.982934] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Odorants are discriminated by hundreds of odorant receptor (OR) genes, which are dispersed throughout the mammalian genome. The OR genes are expressed in a highly specialized type of cell, the olfactory sensory neuron. Each one of these neurons expresses one of the 2 alleles from one single OR gene type. The mechanisms underlying OR gene expression are unclear. Here we describe recent work demonstrating that the olfactory sensory neuron shows a particular nuclear architecture, and that the genomic OR loci are colocalized in silencing heterochromatin compartments within the nucleus. These discoveries highlight the important role played by epigenetic modifications and nuclear genome organization in the regulation of OR gene expression.
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Abstract
The sense of smell is mediated by the detection of chemical odours by ORs (olfactory receptors) in the nose. This initiates a neural percept of the odour in the brain, which may provoke an emotional or behavioural response. Analogous to colour-blindness in the visual system, some individuals report a very different percept of specific odours to others, in terms of intensity, valence or detection threshold. A significant proportion of variance in odour perception is heritable, and recent advances in genome sequencing and genotyping technologies have permitted studies into the genes that underpin these phenotypic differences. In the present article, I review the evidence that OR genes are extremely variable between individuals. I argue that this contributes to a unique receptor repertoire in our noses that provides us each with a personalized perception of our environment. I highlight specific examples where known OR variants influence odour detection and discuss the wider implications of this for both humans and other mammals that use chemical communication for social interaction.
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62
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Gonzalez-Kristeller DC, do Nascimento JBP, Galante PAF, Malnic B. Identification of agonists for a group of human odorant receptors. Front Pharmacol 2015; 6:35. [PMID: 25784876 PMCID: PMC4347425 DOI: 10.3389/fphar.2015.00035] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/11/2015] [Indexed: 11/13/2022] Open
Abstract
Olfaction plays a critical role in several aspects of the human life. Odorants are detected by hundreds of odorant receptors (ORs) which belong to the superfamily of G protein-coupled receptors. These receptors are expressed in the olfactory sensory neurons of the nose. The information provided by the activation of different combinations of ORs in the nose is transmitted to the brain, leading to odorant perception and emotional and behavioral responses. There are ~400 intact human ORs, and to date only a small percentage of these receptors (~10%) have known agonists. The determination of the specificity of the human ORs will contribute to a better understanding of how odorants are discriminated by the olfactory system. In this work, we aimed to identify human specific ORs, that is, ORs that are present in humans but absent from other species, and their corresponding agonists. To do this, we first selected 22 OR gene sequences from the human genome with no counterparts in the mouse, rat or dog genomes. Then we used a heterologous expression system to screen a subset of these human ORs against a panel of odorants of biological relevance, including foodborne aroma volatiles. We found that different types of odorants are able to activate some of these previously uncharacterized human ORs.
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Affiliation(s)
| | - João B P do Nascimento
- Department of Biochemistry, Institute of Chemistry, University of São Paulo São Paulo, Brazil
| | - Pedro A F Galante
- Centro de Oncologia Molecular, Hospital Sírio-Libanês São Paulo, Brazil
| | - Bettina Malnic
- Department of Biochemistry, Institute of Chemistry, University of São Paulo São Paulo, Brazil
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63
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Jiang Y, Matsunami H. Mammalian odorant receptors: functional evolution and variation. Curr Opin Neurobiol 2015; 34:54-60. [PMID: 25660959 DOI: 10.1016/j.conb.2015.01.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 01/14/2015] [Accepted: 01/17/2015] [Indexed: 10/24/2022]
Abstract
In mammals, the perception of smell starts with the activation of odorant receptors (ORs) by volatile molecules in the environment. The mammalian OR repertoire has been subject to rapid evolution, and is highly diverse within the human population. Recent advances in the functional expression and ligand identification of ORs allow for functional analysis of OR evolution, and reveal that changes in OR protein sequences translate into high degrees of functional variations. Moreover, in several cases the functional variation of a single OR affects the perception of its cognate odor ligand, providing clues as to how an odor is coded at the receptor level.
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Affiliation(s)
- Yue Jiang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; University Program of Genetics and Genomics, Duke University, NC 27710, USA
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC 27710, USA.
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64
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Abstract
Although the human olfactory system is capable of discriminating a vast number of odors, we do not currently understand what chemical features are encoded by olfactory receptors. In large part this is due to a paucity of data in a search space covering the interactions of hundreds of receptors with billions of odorous molecules. Of the approximately 400 intact human odorant receptors, only 10% have a published ligand. Here we used a heterologous luciferase assay to screen 73 odorants against a clone library of 511 human olfactory receptors. This dataset will allow other researchers to interrogate the combinatorial nature of olfactory coding.
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65
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Lübke KT, Pause BM. Always follow your nose: the functional significance of social chemosignals in human reproduction and survival. Horm Behav 2015; 68:134-44. [PMID: 25637403 DOI: 10.1016/j.yhbeh.2014.10.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 10/02/2014] [Accepted: 10/06/2014] [Indexed: 12/22/2022]
Abstract
This article is part of a Special Issue "Chemosignals and Reproduction" Across phyla, chemosensory communication is crucial for mediating a variety of social behaviors, which form the basis for ontogenetic and phylogenetic survival. In the present paper, evidence on chemosensory communication in humans, with special reference to reproduction and survival, will be presented. First, the impact of chemosignals on human reproduction will be reviewed. Work will be presented, showing how chemosensory signals are involved in mate choice and partnership formation by communicating attractiveness and facilitating a partner selection, which is of evolutionary advantage, and furthermore providing information about the level of sexual hormones. In addition to direct effects on phylogenetic survival, chemosignals indirectly aid reproductive success by fostering harm protection. Results will be presented, showing that chemosensory communication aids the emotional bond between mother and child, which in turn motivates parental caretaking and protection, leading to infant survival. Moreover, the likelihood of group survival can be increased through the use of stress-related chemosignals. Stress-related chemosignals induce a stress-related physiology in the perceiver, thereby priming a fight-flight-response, which is necessary for an optimum adaption to environmental harm. Finally, effects of sexual orientation on chemosensory communication will be discussed in terms of their putative role in stabilizing social groups, which might indirectly provide harm protection and foster survival. An integrative model of the presented data will be introduced. In conclusion, an outlook, focusing on the involvement of chemosensory communication in human social behavior and illustrating a novel approach to the significance of chemosensory signals in human survival, will be given.
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Affiliation(s)
- Katrin T Lübke
- Department of Experimental Psychology, University of Düsseldorf, Düsseldorf, Germany.
| | - Bettina M Pause
- Department of Experimental Psychology, University of Düsseldorf, Düsseldorf, Germany.
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66
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Dörrich S, Gelis L, Wolf S, Sunderkötter A, Mahler C, Guschina E, Tacke R, Hatt H, Kraft P. Comparative Analysis of the Olfactory Properties of Silicon/Germanium/Tin Analogues of the Lily-of-the-Valley Odorants Lilial and Bourgeonal. Chempluschem 2014. [DOI: 10.1002/cplu.201402160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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67
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Jaeger S, Reinbach H, Roigard C, McRae J, Pineau B, Chheang S, Beresford M, Rouse S, Jin D, Paisley A, Jia Y, Newcomb R. Sensory characterisation of food and beverage stimuli containing β-ionone and differences between individuals by genotype for rs6591536. Food Res Int 2014. [DOI: 10.1016/j.foodres.2014.02.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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68
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69
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Dunkel A, Steinhaus M, Kotthoff M, Nowak B, Krautwurst D, Schieberle P, Hofmann T. Nature's chemical signatures in human olfaction: a foodborne perspective for future biotechnology. Angew Chem Int Ed Engl 2014; 53:7124-43. [PMID: 24939725 DOI: 10.1002/anie.201309508] [Citation(s) in RCA: 353] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 02/02/2014] [Indexed: 02/03/2023]
Abstract
The biocatalytic production of flavor naturals that determine chemosensory percepts of foods and beverages is an ever challenging target for academic and industrial research. Advances in chemical trace analysis and post-genomic progress at the chemistry-biology interface revealed odor qualities of nature's chemosensory entities to be defined by odorant-induced olfactory receptor activity patterns. Beyond traditional views, this review and meta-analysis now shows characteristic ratios of only about 3 to 40 genuine key odorants for each food, from a group of about 230 out of circa 10 000 food volatiles. This suggests the foodborn stimulus space has co-evolved with, and roughly match our circa 400 olfactory receptors as best natural agonists. This perspective gives insight into nature's chemical signatures of smell, provides the chemical odor codes of more than 220 food samples, and beyond addresses industrial implications for producing recombinants that fully reconstruct the natural odor signatures for use in flavors and fragrances, fully immersive interactive virtual environments, or humanoid bioelectronic noses.
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Affiliation(s)
- Andreas Dunkel
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitnerstrasse 34, 85354 Freising-Weihenstephan (Germany)
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70
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A computational microscope focused on the sense of smell. Biochimie 2014; 107 Pt A:3-10. [PMID: 24952349 DOI: 10.1016/j.biochi.2014.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/07/2014] [Indexed: 11/24/2022]
Abstract
In this article, we review studies of the protagonists of the perception of smell focusing on Odorant-Binding Proteins and Olfactory Receptors. We notably put forward studies performed by means of molecular modeling, generally combined with experimental data. Those works clearly emphasize that computational approaches are now a force to reckon with. In the future, they will certainly be more and more used, notably in the framework of a computational microscope meant to observe how the laws of physics govern the biomolecular systems originating our sense of smell.
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71
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Dunkel A, Steinhaus M, Kotthoff M, Nowak B, Krautwurst D, Schieberle P, Hofmann T. Genuine Geruchssignaturen der Natur – Perspektiven aus der Lebensmittelchemie für die Biotechnologie. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309508] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Andreas Dunkel
- Lehrstuhl für Lebensmittelchemie und molekulare Sensorik, Technische Universität München, Lise‐Meitner‐Straße 34, 85354 Freising‐Weihenstephan (Deutschland)
| | - Martin Steinhaus
- Deutsche Forschungsanstalt für Lebensmittelchemie – Leibniz Institut, Lise‐Meitner‐Straße 34, 85354 Freising‐Weihenstephan (Deutschland)
| | - Matthias Kotthoff
- Deutsche Forschungsanstalt für Lebensmittelchemie – Leibniz Institut, Lise‐Meitner‐Straße 34, 85354 Freising‐Weihenstephan (Deutschland)
| | - Bettina Nowak
- Deutsche Forschungsanstalt für Lebensmittelchemie – Leibniz Institut, Lise‐Meitner‐Straße 34, 85354 Freising‐Weihenstephan (Deutschland)
| | - Dietmar Krautwurst
- Deutsche Forschungsanstalt für Lebensmittelchemie – Leibniz Institut, Lise‐Meitner‐Straße 34, 85354 Freising‐Weihenstephan (Deutschland)
| | - Peter Schieberle
- Deutsche Forschungsanstalt für Lebensmittelchemie – Leibniz Institut, Lise‐Meitner‐Straße 34, 85354 Freising‐Weihenstephan (Deutschland)
| | - Thomas Hofmann
- Lehrstuhl für Lebensmittelchemie und molekulare Sensorik, Technische Universität München, Lise‐Meitner‐Straße 34, 85354 Freising‐Weihenstephan (Deutschland)
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72
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Trimmer C, Snyder LL, Mainland JD. High-throughput analysis of mammalian olfactory receptors: measurement of receptor activation via luciferase activity. J Vis Exp 2014. [PMID: 24961834 DOI: 10.3791/51640] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Odorants create unique and overlapping patterns of olfactory receptor activation, allowing a family of approximately 1,000 murine and 400 human receptors to recognize thousands of odorants. Odorant ligands have been published for fewer than 6% of human receptors(1-11). This lack of data is due in part to difficulties functionally expressing these receptors in heterologous systems. Here, we describe a method for expressing the majority of the olfactory receptor family in Hana3A cells, followed by high-throughput assessment of olfactory receptor activation using a luciferase reporter assay. This assay can be used to (1) screen panels of odorants against panels of olfactory receptors; (2) confirm odorant/receptor interaction via dose response curves; and (3) compare receptor activation levels among receptor variants. In our sample data, 328 olfactory receptors were screened against 26 odorants. Odorant/receptor pairs with varying response scores were selected and tested in dose response. These data indicate that a screen is an effective method to enrich for odorant/receptor pairs that will pass a dose response experiment, i.e. receptors that have a bona fide response to an odorant. Therefore, this high-throughput luciferase assay is an effective method to characterize olfactory receptors-an essential step toward a model of odor coding in the mammalian olfactory system.
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73
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Thomas-Danguin T, Sinding C, Romagny S, El Mountassir F, Atanasova B, Le Berre E, Le Bon AM, Coureaud G. The perception of odor objects in everyday life: a review on the processing of odor mixtures. Front Psychol 2014; 5:504. [PMID: 24917831 PMCID: PMC4040494 DOI: 10.3389/fpsyg.2014.00504] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 05/08/2014] [Indexed: 11/13/2022] Open
Abstract
Smelling monomolecular odors hardly ever occurs in everyday life, and the daily functioning of the sense of smell relies primarily on the processing of complex mixtures of volatiles that are present in the environment (e.g., emanating from food or conspecifics). Such processing allows for the instantaneous recognition and categorization of smells and also for the discrimination of odors among others to extract relevant information and to adapt efficiently in different contexts. The neurophysiological mechanisms underpinning this highly efficient analysis of complex mixtures of odorants is beginning to be unraveled and support the idea that olfaction, as vision and audition, relies on odor-objects encoding. This configural processing of odor mixtures, which is empirically subject to important applications in our societies (e.g., the art of perfumers, flavorists, and wine makers), has been scientifically studied only during the last decades. This processing depends on many individual factors, among which are the developmental stage, lifestyle, physiological and mood state, and cognitive skills; this processing also presents striking similarities between species. The present review gathers the recent findings, as observed in animals, healthy subjects, and/or individuals with affective disorders, supporting the perception of complex odor stimuli as odor objects. It also discusses peripheral to central processing, and cognitive and behavioral significance. Finally, this review highlights that the study of odor mixtures is an original window allowing for the investigation of daily olfaction and emphasizes the need for knowledge about the underlying biological processes, which appear to be crucial for our representation and adaptation to the chemical environment.
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Affiliation(s)
- Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, CNRS UMR6265, INRA UMR1324, Université de Bourgogne Dijon, France
| | - Charlotte Sinding
- Smell and Taste Clinic, Department of Otorhinolaryngoly TU Dresden, Dresden, Germany
| | - Sébastien Romagny
- Centre des Sciences du Goût et de l'Alimentation, CNRS UMR6265, INRA UMR1324, Université de Bourgogne Dijon, France
| | - Fouzia El Mountassir
- Centre des Sciences du Goût et de l'Alimentation, CNRS UMR6265, INRA UMR1324, Université de Bourgogne Dijon, France
| | | | | | - Anne-Marie Le Bon
- Centre des Sciences du Goût et de l'Alimentation, CNRS UMR6265, INRA UMR1324, Université de Bourgogne Dijon, France
| | - Gérard Coureaud
- Centre des Sciences du Goût et de l'Alimentation, CNRS UMR6265, INRA UMR1324, Université de Bourgogne Dijon, France
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74
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Verbeurgt C, Wilkin F, Tarabichi M, Gregoire F, Dumont JE, Chatelain P. Profiling of olfactory receptor gene expression in whole human olfactory mucosa. PLoS One 2014; 9:e96333. [PMID: 24800820 PMCID: PMC4011832 DOI: 10.1371/journal.pone.0096333] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/07/2014] [Indexed: 11/19/2022] Open
Abstract
Olfactory perception is mediated by a large array of olfactory receptor genes. The human genome contains 851 olfactory receptor gene loci. More than 50% of the loci are annotated as nonfunctional due to frame-disrupting mutations. Furthermore haplotypic missense alleles can be nonfunctional resulting from substitution of key amino acids governing protein folding or interactions with signal transduction components. Beyond their role in odor recognition, functional olfactory receptors are also required for a proper targeting of olfactory neuron axons to their corresponding glomeruli in the olfactory bulb. Therefore, we anticipate that profiling of olfactory receptor gene expression in whole human olfactory mucosa and analysis in the human population of their expression should provide an opportunity to select the frequently expressed and potentially functional olfactory receptors in view of a systematic deorphanization. To address this issue, we designed a TaqMan Low Density Array (Applied Biosystems), containing probes for 356 predicted human olfactory receptor loci to investigate their expression in whole human olfactory mucosa tissues from 26 individuals (13 women, 13 men; aged from 39 to 81 years, with an average of 67±11 years for women and 63±12 years for men). Total RNA isolation, DNase treatment, RNA integrity evaluation and reverse transcription were performed for these 26 samples. Then 384 targeted genes (including endogenous control genes and reference genes specifically expressed in olfactory epithelium for normalization purpose) were analyzed using the same real-time reverse transcription PCR platform. On average, the expression of 273 human olfactory receptor genes was observed in the 26 selected whole human olfactory mucosa analyzed, of which 90 were expressed in all 26 individuals. Most of the olfactory receptors deorphanized to date on the basis of sensitivity to known odorant molecules, which are described in the literature, were found in the expressed olfactory receptors gene set.
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Affiliation(s)
- Christophe Verbeurgt
- Department of Otorhinolaryngology, Erasme University Hospital, Brussels, Belgium
| | | | - Maxime Tarabichi
- Institute of Interdisciplinary Research in human and molecular Biology, Free University of Brussels, Brussels, Belgium
| | - Françoise Gregoire
- Laboratory of Pathophysiological and Nutritional Biochemistry, Department of Biochemistry, Free University of Brussels, Brussels, Belgium
| | - Jacques E. Dumont
- Institute of Interdisciplinary Research in human and molecular Biology, Free University of Brussels, Brussels, Belgium
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75
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Abstract
Mutations in odorant receptor genes predict olfactory perception of common compounds in foods and flowers. Through recombination they can generate extensive combinatorial variation in sensory ability among individuals.
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Affiliation(s)
- Stephen Wooding
- Health Sciences Research Institute, University of California at Merced, 5200 North Lake Road, Merced, CA 95343, USA.
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76
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Peterlin Z, Firestein S, Rogers ME. The state of the art of odorant receptor deorphanization: a report from the orphanage. ACTA ACUST UNITED AC 2014; 143:527-42. [PMID: 24733839 PMCID: PMC4003190 DOI: 10.1085/jgp.201311151] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The odorant receptors (ORs) provide our main gateway to sensing the world of volatile chemicals. This involves a complex encoding process in which multiple ORs, each of which detects its own set of odorants, work as an ensemble to produce a distributed activation code that is presumably unique to each odorant. One marked challenge to decoding the olfactory code is OR deorphanization, the identification of a set of activating odorants for a particular receptor. Here, we survey various methods used to try to express defined ORs of interest. We also suggest strategies for selecting odorants for test panels to evaluate the functional expression of an OR. Integrating these tools, while retaining awareness of their idiosyncratic limitations, can provide a multi-tiered approach to OR deorphanization, spanning the initial discovery of a ligand to vetting that ligand in a physiologically relevant setting.
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Affiliation(s)
- Zita Peterlin
- Corporate Research and Development, Firmenich Incorporated, Plainsboro, NJ 08536
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77
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Stathopoulos S, Bishop JM, O’Ryan C. Genetic signatures for enhanced olfaction in the African mole-rats. PLoS One 2014; 9:e93336. [PMID: 24699281 PMCID: PMC3974769 DOI: 10.1371/journal.pone.0093336] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 03/03/2014] [Indexed: 01/06/2023] Open
Abstract
The Olfactory Receptor (OR) superfamily, the largest in the vertebrate genome, is responsible for vertebrate olfaction and is traditionally subdivided into 17 OR families. Recent studies characterising whole-OR subgenomes revealed a 'birth and death' model of evolution for a range of species, however little is known about fine-scale evolutionary dynamics within single-OR families. This study reports the first assessment of fine-scale OR evolution and variation in African mole-rats (Bathyergidae), a family of subterranean rodents endemic to sub-Saharan Africa. Because of the selective pressures of life underground, enhanced olfaction is proposed to be fundamental to the evolutionary success of the Bathyergidae, resulting in a highly diversified OR gene-repertoire. Using a PCR-sequencing approach, we analysed variation in the OR7 family across 14 extant bathyergid species, which revealed enhanced levels of functional polymorphisms concentrated across the receptors' ligand-binding region. We propose that mole-rats are able to recognise a broad range of odorants and that this diversity is reflected throughout their OR7 gene repertoire. Using both classic tests and tree-based methods to test for signals of selection, we investigate evolutionary forces across the mole-rat OR7 gene tree. Four well-supported clades emerged in the OR phylogeny, with varying signals of selection; from neutrality to positive and purifying selection. Bathyergid life-history traits and environmental niche-specialisation are explored as possible drivers of adaptive OR evolution, emerging as non-exclusive contributors to the positive selection observed at OR7 genes. Our results reveal unexpected complexity of evolutionary mechanisms acting within a single OR family, providing insightful perspectives into OR evolutionary dynamics.
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Affiliation(s)
- Sofia Stathopoulos
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Cape, South Africa
- * E-mail:
| | - Jacqueline M. Bishop
- Department of Biological Sciences, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Colleen O’Ryan
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Cape, South Africa
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78
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Secundo L, Snitz K, Sobel N. The perceptual logic of smell. Curr Opin Neurobiol 2014; 25:107-15. [DOI: 10.1016/j.conb.2013.12.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/05/2013] [Accepted: 12/18/2013] [Indexed: 12/01/2022]
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79
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Ignatieva EV, Levitsky VG, Yudin NS, Moshkin MP, Kolchanov NA. Genetic basis of olfactory cognition: extremely high level of DNA sequence polymorphism in promoter regions of the human olfactory receptor genes revealed using the 1000 Genomes Project dataset. Front Psychol 2014; 5:247. [PMID: 24715883 PMCID: PMC3970011 DOI: 10.3389/fpsyg.2014.00247] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 03/05/2014] [Indexed: 11/13/2022] Open
Abstract
The molecular mechanism of olfactory cognition is very complicated. Olfactory cognition is initiated by olfactory receptor proteins (odorant receptors), which are activated by olfactory stimuli (ligands). Olfactory receptors are the initial player in the signal transduction cascade producing a nerve impulse, which is transmitted to the brain. The sensitivity to a particular ligand depends on the expression level of multiple proteins involved in the process of olfactory cognition: olfactory receptor proteins, proteins that participate in signal transduction cascade, etc. The expression level of each gene is controlled by its regulatory regions, and especially, by the promoter [a region of DNA about 100–1000 base pairs long located upstream of the transcription start site (TSS)]. We analyzed single nucleotide polymorphisms using human whole-genome data from the 1000 Genomes Project and revealed an extremely high level of single nucleotide polymorphisms in promoter regions of olfactory receptor genes and HLA genes. We hypothesized that the high level of polymorphisms in olfactory receptor promoters was responsible for the diversity in regulatory mechanisms controlling the expression levels of olfactory receptor proteins. Such diversity of regulatory mechanisms may cause the great variability of olfactory cognition of numerous environmental olfactory stimuli perceived by human beings (air pollutants, human body odors, odors in culinary etc.). In turn, this variability may provide a wide range of emotional and behavioral reactions related to the vast variety of olfactory stimuli.
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Affiliation(s)
- Elena V Ignatieva
- Laboratory of Evolutionary Bioinformatics and Theoretical Genetics, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia ; Department of Natural Science, Novosibirsk State University Novosibirsk, Russia
| | - Victor G Levitsky
- Department of Natural Science, Novosibirsk State University Novosibirsk, Russia ; Laboratory of Molecular-Genetic Systems, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia
| | - Nikolay S Yudin
- Department of Natural Science, Novosibirsk State University Novosibirsk, Russia ; Laboratory of Human Molecular Genetics, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia
| | - Mikhail P Moshkin
- Department of Natural Science, Novosibirsk State University Novosibirsk, Russia ; Laboratory of Mammalian Ecological Genetics, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia
| | - Nikolay A Kolchanov
- Department of Natural Science, Novosibirsk State University Novosibirsk, Russia ; Department of Systems Biology, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences Novosibirsk, Russia ; National Research centre "Kurchatov Institute" Moscow, Russia
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80
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Sex-hormone dependent perception of androstenone suggests its involvement in communicating competition and aggression. Physiol Behav 2014; 123:136-41. [DOI: 10.1016/j.physbeh.2013.10.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 07/10/2013] [Accepted: 10/18/2013] [Indexed: 11/21/2022]
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81
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The missense of smell: functional variability in the human odorant receptor repertoire. Nat Neurosci 2013; 17:114-20. [PMID: 24316890 PMCID: PMC3990440 DOI: 10.1038/nn.3598] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 11/05/2013] [Indexed: 11/09/2022]
Abstract
Humans have ~400 intact odorant receptors, but each individual has a unique set of genetic variations that lead to variation in olfactory perception. We used a heterologous assay to determine how often genetic polymorphisms in odorant receptors alter receptor function. We identified agonists for 18 odorant receptors and found that 63% of the odorant receptors we examined had polymorphisms that altered in vitro function. On average, two individuals have functional differences at over 30% of their odorant receptor alleles. To show that these in vitro results are relevant to olfactory perception, we verified that variations in OR10G4 genotype explain over 15% of the observed variation in perceived intensity and over 10% of the observed variation in perceived valence for the high-affinity in vitro agonist guaiacol but do not explain phenotype variation for the lower-affinity agonists vanillin and ethyl vanillin.
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82
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Patel RM, Pinto JM. Olfaction: anatomy, physiology, and disease. Clin Anat 2013; 27:54-60. [PMID: 24272785 DOI: 10.1002/ca.22338] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/02/2013] [Indexed: 11/08/2022]
Abstract
The olfactory system is an essential part of human physiology, with a rich evolutionary history. Although humans are less dependent on chemosensory input than are other mammals (Niimura 2009, Hum. Genomics 4:107-118), olfactory function still plays a critical role in health and behavior. The detection of hazards in the environment, generating feelings of pleasure, promoting adequate nutrition, influencing sexuality, and maintenance of mood are described roles of the olfactory system, while other novel functions are being elucidated. A growing body of evidence has implicated a role for olfaction in such diverse physiologic processes as kin recognition and mating (Jacob et al. 2002a, Nat. Genet. 30:175-179; Horth 2007, Genomics 90:159-175; Havlicek and Roberts 2009, Psychoneuroendocrinology 34:497-512), pheromone detection (Jacob et al. 200b, Horm. Behav. 42:274-283; Wyart et al. 2007, J. Neurosci. 27:1261-1265), mother-infant bonding (Doucet et al. 2009, PLoS One 4:e7579), food preferences (Mennella et al. 2001, Pediatrics 107:E88), central nervous system physiology (Welge-Lüssen 2009, B-ENT 5:129-132), and even longevity (Murphy 2009, JAMA 288:2307-2312). The olfactory system, although phylogenetically ancient, has historically received less attention than other special senses, perhaps due to challenges related to its study in humans. In this article, we review the anatomic pathways of olfaction, from peripheral nasal airflow leading to odorant detection, to epithelial recognition of these odorants and related signal transduction, and finally to central processing. Olfactory dysfunction, which can be defined as conductive, sensorineural, or central (typically related to neurodegenerative disorders), is a clinically significant problem, with a high burden on quality of life that is likely to grow in prevalence due to demographic shifts and increased environmental exposures.
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Affiliation(s)
- Riddhi M Patel
- Department of Surgery, Section of Otolaryngology-Head and Neck Surgery, The University of Chicago, Chicago, Illinois
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83
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Hummel T, Olgun S, Gerber J, Huchel U, Frasnelli J. Brain responses to odor mixtures with sub-threshold components. Front Psychol 2013; 4:786. [PMID: 24167499 PMCID: PMC3807048 DOI: 10.3389/fpsyg.2013.00786] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 10/07/2013] [Indexed: 11/13/2022] Open
Abstract
Although most odorants we encounter in daily life are mixtures of several chemical substances, we still lack significant information on how we perceive and how the brain processes mixtures of odorants. We aimed to investigate the processing of odor mixtures using behavioral measures and functional magnetic resonance imaging (fMRI). The odor mixture contained a target odor (ambroxan) in a concentration at which it could be perceived by half of the subjects (sensitive group); the other half could not perceive the odor (insensitive group). In line with previous findings on multi-component odor mixtures, both groups of subjects were not able to distinguish a complex odor mixture containing or not containing the target odor. However, sensitive subjects had stronger activations than insensitive subjects in chemosensory processing areas such as the insula when exposed to the mixture containing the target odor. Furthermore, the sensitive group exhibited larger brain activations when presented with the odor mixture containing the target odor compared to the odor mixture without the target odor; this difference was smaller, though present for the insensitive group. In conclusion, we show that a target odor presented within a mixture of odors can influence brain activations although on a psychophysical level subjects are not able to distinguish the mixture with and without the target. On the practical side these results suggest that the addition of a certain compound to a mixture of odors may not be detected on a cognitive level; however, this additional odor may significantly change the cerebral processing of this mixture. In this context, FMRI offers unique possibilities to look at the subliminal effects of odors.
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Affiliation(s)
- Thomas Hummel
- Department of Otorhinolaryngology, Technical University of Dresden Medical School Dresden, Germany
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84
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Auffarth B. Understanding smell—The olfactory stimulus problem. Neurosci Biobehav Rev 2013; 37:1667-79. [DOI: 10.1016/j.neubiorev.2013.06.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 05/09/2013] [Accepted: 06/13/2013] [Indexed: 01/30/2023]
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85
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Identification of Regions Associated with Variation in Sensitivity to Food-Related Odors in the Human Genome. Curr Biol 2013; 23:1596-600. [DOI: 10.1016/j.cub.2013.07.031] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/16/2013] [Accepted: 07/03/2013] [Indexed: 12/19/2022]
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86
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Jaeger SR, McRae JF, Bava CM, Beresford MK, Hunter D, Jia Y, Chheang SL, Jin D, Peng M, Gamble JC, Atkinson KR, Axten LG, Paisley AG, Tooman L, Pineau B, Rouse SA, Newcomb RD. A Mendelian trait for olfactory sensitivity affects odor experience and food selection. Curr Biol 2013; 23:1601-5. [PMID: 23910657 DOI: 10.1016/j.cub.2013.07.030] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 05/27/2013] [Accepted: 07/03/2013] [Indexed: 11/25/2022]
Abstract
Humans vary in acuity to many odors [1-4], with variation within olfactory receptor (OR) genes contributing to these differences [5-9]. How such variation also affects odor experience and food selection remains uncertain [10], given that such effects occur for taste [11-15]. Here we investigate β-ionone, which shows extreme sensitivity differences [4, 16, 17]. β-ionone is a key aroma in foods and beverages [18-21] and is added to products in order to give a pleasant floral note [22, 23]. Genome-wide and in vitro assays demonstrate rs6591536 as the causal variant for β-ionone odor sensitivity. rs6591536 encodes a N183D substitution in the second extracellular loop of OR5A1 and explains >96% of the observed phenotypic variation, resembling a monogenic Mendelian trait. Individuals carrying genotypes for β-ionone sensitivity can more easily differentiate between food and beverage stimuli with and without added β-ionone. Sensitive individuals typically describe β-ionone in foods and beverages as "fragrant" and "floral," whereas less-sensitive individuals describe these stimuli differently. rs6591536 genotype also influences emotional associations and explains differences in food and product choices. These studies demonstrate that an OR variant that influences olfactory sensitivity can affect how people experience and respond to foods, beverages, and other products.
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Affiliation(s)
- Sara R Jaeger
- New Zealand Institute for Plant and Food Research, Auckland 1025, New Zealand
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87
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88
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Olender T, Safran M, Edgar R, Stelzer G, Nativ N, Rosen N, Shtrichman R, Mazor Y, West MD, Keydar I, Rappaport N, Belinky F, Warshawsky D, Lancet D. An Overview of Synergistic Data Tools for Biological Scrutiny. Isr J Chem 2013. [DOI: 10.1002/ijch.201200094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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89
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Havlícek J, Nováková L, Vondrová M, Kubena AA, Valentová J, Roberts SC. Olfactory perception is positively linked to anxiety in young adults. Perception 2013; 41:1246-61. [PMID: 23469704 DOI: 10.1068/p7244] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Olfactory abilities show a high degree of inter-individual variability and this could be partly related to personality differences. Here, in two studies, we tested a potential link between personality dimensions and olfactory perception. Sixty-eight (study 1) and a hundred and fifty-six (study 2) young adults completed the Big Five questionnaire and performed the Sniffin' Sticks test for assessing odour threshold, identification, and (in study 2) discrimination. In neither study did we find a significant link between personality dimensions and olfactory identification scores. However, in study 1, we found a significant positive correlation between the neuroticism dimension and olfactory sensitivity. This was mainly due to the anxiety and self-consciousness subscales, which load onto the neuroticism dimension. In a follow-up study, we again found a significant association between anxiety and odour perception, specifically in odour discrimination. Our results indicate that variability in anxiety could partly explain the high inter-individual variation in olfactory perception.
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Affiliation(s)
- Jan Havlícek
- Department of Anthropology, Faculty of Humanities, Charles University, U Kríze 8, 158 00 Prague 5, Czech Republic.
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90
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Decreased Perception of Bourgeonal May Be Linked to Male Idiopathic Infertility. Chem Senses 2013; 38:439-45. [DOI: 10.1093/chemse/bjt009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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91
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Kybert NJ, Lerner MB, Yodh JS, Preti G, Johnson ATC. Differentiation of complex vapor mixtures using versatile DNA-carbon nanotube chemical sensor arrays. ACS NANO 2013; 7:2800-7. [PMID: 23442175 DOI: 10.1021/nn400359c] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Vapor sensors based on functionalized carbon nanotubes (NTs) have shown great promise, with high sensitivity conferred by the reduced dimensionality and exceptional electronic properties of the NT. Critical challenges in the development of NT-based sensor arrays for chemical detection include the demonstration of reproducible fabrication methods and functionalization schemes that provide high chemical diversity to the resulting sensors. Here, we outline a scalable approach to fabricating arrays of vapor sensors consisting of NT field effect transistors functionalized with single-stranded DNA (DNA-NT). DNA-NT sensors were highly reproducible, with responses that could be described through equilibrium thermodynamics. Target analytes were detected even in large backgrounds of volatile interferents. DNA-NT sensors were able to discriminate between highly similar molecules, including structural isomers and enantiomers. The sensors were also able to detect subtle variations in complex vapors, including mixtures of structural isomers and mixtures of many volatile organic compounds characteristic of humans.
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Affiliation(s)
- Nicholas J Kybert
- Department of Physics and Astronomy and Nano/Bio Interface Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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92
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Wallrabenstein I, Kuklan J, Weber L, Zborala S, Werner M, Altmüller J, Becker C, Schmidt A, Hatt H, Hummel T, Gisselmann G. Human trace amine-associated receptor TAAR5 can be activated by trimethylamine. PLoS One 2013; 8:e54950. [PMID: 23393561 PMCID: PMC3564852 DOI: 10.1371/journal.pone.0054950] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 12/17/2012] [Indexed: 11/19/2022] Open
Abstract
In addition to the canonical olfactory receptors, TAARs were currently suggested to be a second class of chemosensory receptors in the olfactory epithelium of vertebrates. In contrast to several deorphanized murine TAARs, agonists for the intact human TAAR genes 2, 5, 6, 8 and 9 that are potentially expressed in the human olfactory epithelium have not been determined so far. Moreover, the physiological relevance of TAARs still remains elusive. We present the first successful functional expression of a human TAAR and agonists of human TAAR5. We performed a ligand screening using recombinantly expressed human TAAR5 in HANA3A cells and Xenopus laevis oocytes. In order to measure receptor activity, we used a cAMP-dependent reporter gene assay and two-electrode voltage clamp technique. As a result, human TAAR5 can be activated in a concentration-dependent manner by trimethylamine and with less efficacy by dimethylethylamine. It could neither be activated by any other of the tested single amines with a related chemical structure (42 in total), nor by any of the tested odorant mixtures. The hypothesis that Single Nucleotide Polymorphisms (SNP) within the reading frame of an olfactory receptor gene can cause a specific anosmia, formed the basis for clarifying the question, if anosmia for trimethylamine is caused by a SNP in a TAAR coding sequence. All functional human TAAR gene reading frames of subjects with specific anosmia for trimethylamine were amplified and products analyzed regarding SNP distribution. We demonstrated that the observed specific anosmia for trimethylamine is not correlated with a SNP in the coding sequence of one of the putatively functional human TAAR genes.
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93
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Hinkley CS, Ismaili L. A rapid genotyping assay for segregating human olfactory receptor pseudogenes. J Biomol Tech 2013; 23:84-9. [PMID: 23002384 DOI: 10.7171/jbt.12-2303-001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Variation in odor perception between individuals is initiated by binding of "odorant" molecules to olfactory receptors (ORs) located in the nasal cavity. To determine the mechanism for variation in odor perception, identification of specific ligands for a large number of ORs is required. However, it has been difficult to identify specific ligands, and ligands have been identified for only 2-3% of the hundreds of mammalian ORs. One way to increase the number of identified ligands is to take advantage of >60 human OR genes that are segregating as a result of a single nucleotide polymorphism, between a functional intact allele and a nonfunctional pseudogene allele. Potential ligands for these ORs can be identified by correlating odor perception of an individual with their genotype [intact/intact (I/I) vs. pseudogene/pseudogene (P/P)] for an OR gene. For this type of study, genotypes must be determined for a large number of individuals. We have developed a PCR-based assay to distinguish between the intact and pseudogene alleles of 49 segregating human OR genes and to determine an individual's genotype for these genes. To facilitate rapid determination of genotypes for a large number of individuals, the assay uses a small number of simple steps and equipment commonly found in most molecular biology and biochemistry laboratories. Although this assay was developed to distinguish between polymorphisms in OR genes, it can easily be adapted for use in distinguishing single nucleotide polymorphisms in any gene or chromosomal locus.
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Affiliation(s)
- Craig S Hinkley
- Department of Biological Sciences, Kingsborough Community College, Brooklyn, New York 11235, USA.
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94
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Abstract
Olfactory receptors (ORs) constitute the largest gene family in the mammalian genome. The existence of these proteins underlies the nature of, and variability in, odorant perception. The Human Olfactory Receptor Data Explorer (HORDE, http://genome.weizmann.ac.il/horde/ ) is a free online resource, which presents a complete compendium of all OR genes and pseudogenes in the genome of human and four other vertebrates. HORDE includes three parts: (1) an automated pipeline, which mines OR gene and pseudogene sequences out of complete genomes, and generates gene symbols based on sequence similarity; (2) a card generator that obtains and displays annotative information on individual ORs retrieved from external databases and relevant studies; and (3) a search engine that allows user retrieval of OR information. For human ORs, HORDE specifically addresses the universe of interindividual variation, as obtained from several sources, including whole genome sequences made possible by next-generation sequencing. This encompasses single nucleotide polymorphisms (SNP) and copy number variation (CNV), including deleterious mutational events. HORDE also hosts a number of tools designed specifically to assist in the study of OR evolution and function. In this chapter, we describe the status of HORDE (build #43). We also discuss plans for future enhancements and a road map for HORDE to become a better community-based bioinformatics tool. We highlight HORDE's role as a major research tool in the study of an expanding cohort of OR repertoires.
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Affiliation(s)
- Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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95
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Keydar I, Ben-Asher E, Feldmesser E, Nativ N, Oshimoto A, Restrepo D, Matsunami H, Chien MS, Pinto JM, Gilad Y, Olender T, Lancet D. General olfactory sensitivity database (GOSdb): candidate genes and their genomic variations. Hum Mutat 2013; 34:32-41. [PMID: 22936402 PMCID: PMC3627721 DOI: 10.1002/humu.22212] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 08/24/2012] [Indexed: 12/22/2022]
Abstract
Genetic variations in olfactory receptors likely contribute to the diversity of odorant-specific sensitivity phenotypes. Our working hypothesis is that genetic variations in auxiliary olfactory genes, including those mediating transduction and sensory neuronal development, may constitute the genetic basis for general olfactory sensitivity (GOS) and congenital general anosmia (CGA). We thus performed a systematic exploration for auxiliary olfactory genes and their documented variation. This included a literature survey, seeking relevant functional in vitro studies, mouse gene knockouts and human disorders with olfactory phenotypes, as well as data mining in published transcriptome and proteome data for genes expressed in olfactory tissues. In addition, we performed next-generation transcriptome sequencing (RNA-seq) of human olfactory epithelium and mouse olfactory epithelium and bulb, so as to identify sensory-enriched transcripts. Employing a global score system based on attributes of the 11 data sources utilized, we identified a list of 1,680 candidate auxiliary olfactory genes, of which 450 are shortlisted as having higher probability of a functional role. For the top-scoring 136 genes, we identified genomic variants (probably damaging single nucleotide polymorphisms, indels, and copy number deletions) gleaned from public variation repositories. This database of genes and their variants should assist in rationalizing the great interindividual variation in human overall olfactory sensitivity (http://genome.weizmann.ac.il/GOSdb).
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Affiliation(s)
- Ifat Keydar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Edna Ben-Asher
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ester Feldmesser
- Bioinformatics Unit, Department of Biological Services, Weizmann Institute of Science, Rehovot, Israel
| | - Noam Nativ
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Arisa Oshimoto
- Department of Cell and Developmental Biology, Neuroscience Program, and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, Colorado
| | - Diego Restrepo
- Department of Cell and Developmental Biology, Neuroscience Program, and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, Colorado
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina
| | - Ming-Shan Chien
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina
| | - Jayant M. Pinto
- Section of Otolaryngology-Head and Neck Surgery, University of Chicago, Chicago, Illinois
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, Illinois
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Doron Lancet
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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96
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Krautwurst D, Kotthoff M. A hit map-based statistical method to predict best ligands for orphan olfactory receptors: natural key odorants versus "lock picks". Methods Mol Biol 2013; 1003:85-97. [PMID: 23585035 DOI: 10.1007/978-1-62703-377-0_6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Smell is a multidimensional chemical sense. It creates a perception of our odorous environment by integrating the information of a plethora of volatile chemicals with other sensory inputs, emotions and memories. We are almost always exposed to odorant mixtures, not just single chemicals. Olfactory processing of complex odorant mixtures, such as coffee or wine, first is decoded at the site of perception by the hundreds of different olfactory receptor types, each residing in the cilia of their olfactory sensory neurons in the nose. Often, only a few odorants from many are essential to determine complex olfactory perception. But merely using the chemical structure of odorants is insufficient to identify and predict characteristic odor qualities and low odor thresholds. An understanding of odorant coding critically depends on knowledge about the interaction of key odorants of biologically relevant odor bouquets with their best cognate receptors. Here, we describe a hit map-based method of correlating the information content of all bioassay-tested odorants with their cognate odorant-receptor frequency in four phylogenetic subsets of human olfactory/chemosensory receptors.
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Affiliation(s)
- Dietmar Krautwurst
- German Research Center for Food Chemistry, Leibniz Institute, Freising, Germany
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97
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Perceptual convergence of multi-component mixtures in olfaction implies an olfactory white. Proc Natl Acad Sci U S A 2012; 109:19959-64. [PMID: 23169632 DOI: 10.1073/pnas.1208110109] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In vision, two mixtures, each containing an independent set of many different wavelengths, may produce a common color percept termed "white." In audition, two mixtures, each containing an independent set of many different frequencies, may produce a common perceptual hum termed "white noise." Visual and auditory whites emerge upon two conditions: when the mixture components span stimulus space, and when they are of equal intensity. We hypothesized that if we apply these same conditions to odorant mixtures, "whiteness" may emerge in olfaction as well. We selected 86 molecules that span olfactory stimulus space and individually diluted them to a point of about equal intensity. We then prepared various odorant mixtures, each containing various numbers of molecular components, and asked human participants to rate the perceptual similarity of such mixture pairs. We found that as we increased the number of nonoverlapping, equal-intensity components in odorant mixtures, the mixtures became more similar to each other, despite not having a single component in common. With ~30 components, most mixtures smelled alike. After participants were acquainted with a novel, arbitrarily named mixture of ~30 equal-intensity components, they later applied this name more readily to other novel mixtures of ~30 equal-intensity components spanning stimulus space, but not to mixtures containing fewer components or to mixtures that did not span stimulus space. We conclude that a common olfactory percept, "olfactory white," is associated with mixtures of ~30 or more equal-intensity components that span stimulus space, implying that olfactory representations are of features of molecules rather than of molecular identity.
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98
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Keller A, Hempstead M, Gomez IA, Gilbert AN, Vosshall LB. An olfactory demography of a diverse metropolitan population. BMC Neurosci 2012; 13:122. [PMID: 23046643 PMCID: PMC3493268 DOI: 10.1186/1471-2202-13-122] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 09/28/2012] [Indexed: 01/28/2023] Open
Abstract
Background Human perception of the odour environment is highly variable. People vary both in their general olfactory acuity as well as in if and how they perceive specific odours. In recent years, it has been shown that genetic differences contribute to variability in both general olfactory acuity and the perception of specific odours. Odour perception also depends on other factors such as age and gender. Here we investigate the influence of these factors on both general olfactory acuity and on the perception of 66 structurally and perceptually different odours in a diverse subject population. Results We carried out a large human olfactory psychophysics study of 391 adult subjects in metropolitan New York City, an ethnically and culturally diverse North American metropolis. 210 of the subjects were women and the median age was 34.6 years (range 19–75). We recorded ~2,300 data points per subject to obtain a comprehensive perceptual phenotype, comprising multiple perceptual measures of 66 diverse odours. We show that general olfactory acuity correlates with gender, age, race, smoking habits, and body type. Young, female, non-smoking subjects had the highest average olfactory acuity. Deviations from normal body type in either direction were associated with decreased olfactory acuity. Beyond these factors we also show that, surprisingly, there are many odour-specific influences of race, age, and gender on olfactory perception. We show over 100 instances in which the intensity or pleasantness perception of an odour is significantly different between two demographic groups. Conclusions These data provide a comprehensive snapshot of the olfactory sense of a diverse population. Olfactory acuity in the population is most strongly influenced by age, followed by gender. We also show a large number of diverse correlations between demographic factors and the perception of individual odours that may reflect genetic differences as well as different prior experiences with these odours between demographic groups.
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Affiliation(s)
- Andreas Keller
- Laboratory of Neurogenetics and Behaviour, The Rockefeller University, 1230 York Avenue, Box 63, New York, NY 10065, USA
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99
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Niimura Y. Olfactory receptor multigene family in vertebrates: from the viewpoint of evolutionary genomics. Curr Genomics 2012; 13:103-14. [PMID: 23024602 PMCID: PMC3308321 DOI: 10.2174/138920212799860706] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 07/12/2011] [Accepted: 09/29/2011] [Indexed: 01/17/2023] Open
Abstract
Olfaction is essential for the survival of animals. Diverse odor molecules in the environment are detected by the olfactory receptors (ORs) in the olfactory epithelium of the nasal cavity. There are ~400 and ~1,000 OR genes in the human and mouse genomes, respectively, forming the largest multigene family in mammals. The relationships between ORs and odorants are multiple-to-multiple, which allows for discriminating almost unlimited number of different odorants by a combination of ORs. However, the OR-ligand relationships are still largely unknown, and predicting the quality of odor from its molecular structure is unsuccessful.Extensive bioinformatic analyses using the whole genomes of various organisms revealed a great variation in number of OR genes among species, reflecting the diversity of their living environments. For example, higher primates equipped with a well-developed vision system and dolphins that are secondarily adapted to the aquatic life have considerably smaller numbers of OR genes than most of other mammals do. OR genes are characterized by extremely frequent gene duplications and losses. The OR gene repertories are also diverse among human individuals, explaining the diversity of odor perception such as the specific anosmia.OR genes are present in all vertebrates. The number of OR genes is smaller in teleost fishes than in mammals, while the diversity is higher in the former than the latter. Because the genome of amphioxus, the most basal chordate species, harbors vertebrate-like OR genes, the origin of OR genes can be traced back to the common ancestor of the phylum Chordata.
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Affiliation(s)
- Yoshihito Niimura
- Department of Bioinformatics, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
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100
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Knaapila A, Hwang LD, Lysenko A, Duke FF, Fesi B, Khoshnevisan A, James RS, Wysocki CJ, Rhyu M, Tordoff MG, Bachmanov AA, Mura E, Nagai H, Reed DR. Genetic analysis of chemosensory traits in human twins. Chem Senses 2012; 37:869-81. [PMID: 22977065 DOI: 10.1093/chemse/bjs070] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We explored genetic influences on the perception of taste and smell stimuli. Adult twins rated the chemosensory aspects of water, sucrose, sodium chloride, citric acid, ethanol, quinine hydrochloride, phenylthiocarbamide (PTC), potassium chloride, calcium chloride, cinnamon, androstenone, Galaxolide™, cilantro, and basil. For most traits, individual differences were stable over time and some traits were heritable (h(2) from 0.41 to 0.71). Subjects were genotyped for 44 single nucleotide polymorphisms within and near genes related to taste and smell. The results of these association analyses confirmed previous genotype-phenotype results for PTC, quinine, and androstenone. New associations were detected for ratings of basil and a bitter taste receptor gene, TAS2R60, and between cilantro and variants in three genes (TRPA1, GNAT3, and TAS2R50). The flavor of ethanol was related to variation within an olfactory receptor gene (OR7D4) and a gene encoding a subunit of the epithelial sodium channel (SCNN1D). Our study demonstrates that person-to-person differences in the taste and smell perception of simple foods and drinks are partially accounted for by genetic variation within chemosensory pathways.
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Affiliation(s)
- Antti Knaapila
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA
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