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Wang JJ, Ma C, Yue Y, Yang J, Chen LX, Wang YT, Zhao CC, Gao X, Chen HS, Ma WH, Zhou Z. Identification of candidate chemosensory genes in Bactrocera cucurbitae based on antennal transcriptome analysis. Front Physiol 2024; 15:1354530. [PMID: 38440345 PMCID: PMC10910661 DOI: 10.3389/fphys.2024.1354530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/24/2024] [Indexed: 03/06/2024] Open
Abstract
The melon fly, Bactrocera cucurbitae (Coquillett) (Tephritidae: Diptera), is an invasive pest that poses a significant threat to agriculture in Africa and other regions. Flies are known to use their olfactory systems to recognise environmental chemical cues. However, the molecular components of the chemosensory system of B. cucurbitae are poorly characterised. To address this knowledge gap, we have used next-generation sequencing to analyse the antenna transcriptomes of sexually immature B. cucurbitae adults. The results have identified 160 potential chemosensory genes, including 35 odourant-binding proteins (OBPs), one chemosensory protein (CSP), three sensory neuron membrane proteins (SNMPs), 70 odourant receptors (ORs), 30 ionotropic receptors (IRs), and 21 gustatory receptors (GRs). Quantitative real-time polymerase chain reaction quantitative polymerase chain reaction was used to validate the results by assessing the expression profiles of 25 ORs and 15 OBPs. Notably, high expression levels for BcucOBP5/9/10/18/21/23/26 were observed in both the female and male antennae. Furthermore, BcucOROrco/6/7/9/13/15/25/27/28/42/62 exhibited biased expression in the male antennae, whereas BcucOR55 showed biased expression in the female antennae. This comprehensive investigation provides valuable insights into insect olfaction at the molecular level and will, thus, help to facilitate the development of enhanced pest management strategies in the future.
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Affiliation(s)
- Jing Jing Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
| | - Chao Ma
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
| | - Yang Yue
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
| | - Jingfang Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
| | - Li Xiang Chen
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
| | - Yi Ting Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
| | | | - Xuyuan Gao
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
- Guangxi Key Laboratory for Biology of Crop Diseases and Insect Pests, Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Hong Song Chen
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
- Guangxi Key Laboratory for Biology of Crop Diseases and Insect Pests, Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Wei Hua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhongshi Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China
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2
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Ziemba PM, Mueck A, Gisselmann G, Stoertkuhl KF. Functional expression and ligand identification of homo- and heteromeric Drosophila melanogaster CO2 receptors in the Xenopus laevis oocyte system. PLoS One 2023; 18:e0295404. [PMID: 38157355 PMCID: PMC10756536 DOI: 10.1371/journal.pone.0295404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/20/2023] [Indexed: 01/03/2024] Open
Abstract
Carbon dioxide (CO2) is an important olfactory cue in Drosophila melanogaster and can elicit both attractive and aversive behaviors. It is detected by gustatory receptors, Gr21a and Gr63a, found in the ab1C neuron in basiconic sensilla on the third antennal segment. Volatile substances that modulate the receptors' function are of interest for pest control. While several substances block ab1C neurons or mimic the activating effect of carbon dioxide, it is not known if these substances are indeed ligands of the CO2 receptor or might act on other proteins in the receptor neuron. In this study, we used the recombinant Xenopus laevis expression system and two-electrode voltage-clamp technology to investigate the receptor function. We found that application of sodium bicarbonate evokes large inward currents in oocytes co-expressing Gr21a and Gr63a. The receptors most likely form hetromultimeric complexes. Homomultimeric receptors of Gr21a or Gr63a are sufficient for receptor functionality, although oocytes gave significantly lower current responses compared to the probable heteromultimeric receptor. We screened for putative blockers of the sodium bicarbonate response and confirmed that some of the substances identified by spike recordings of olfactory receptor neurons, such as 1-hexanol, are also blockers in the Xenopus oocyte system. We also identified a new blocking substance, citronellol, which is related to insect repellents. Many substances that activate receptor neurons were inactive in the Xenopus oocyte system, indicating that they may not be ligands for the receptor, but may act on other proteins. However, methyl pyruvate and n-hexylamine were found to be activators of the recombinant Gr21a/Gr63a receptor.
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Affiliation(s)
- Paul M. Ziemba
- AG Physiology of Senses, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Alina Mueck
- AG Physiology of Senses, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Günter Gisselmann
- Department of Cell Physiology, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Klemens F. Stoertkuhl
- AG Physiology of Senses, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
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3
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Qian WW, Wei JN, Sanchez-Lengeling B, Lee BK, Luo Y, Vlot M, Dechering K, Peng J, Gerkin RC, Wiltschko AB. Metabolic activity organizes olfactory representations. eLife 2023; 12:e82502. [PMID: 37129358 PMCID: PMC10154027 DOI: 10.7554/elife.82502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 04/11/2023] [Indexed: 05/03/2023] Open
Abstract
Hearing and vision sensory systems are tuned to the natural statistics of acoustic and electromagnetic energy on earth and are evolved to be sensitive in ethologically relevant ranges. But what are the natural statistics of odors, and how do olfactory systems exploit them? Dissecting an accurate machine learning model (Lee et al., 2022) for human odor perception, we find a computable representation for odor at the molecular level that can predict the odor-evoked receptor, neural, and behavioral responses of nearly all terrestrial organisms studied in olfactory neuroscience. Using this olfactory representation (principal odor map [POM]), we find that odorous compounds with similar POM representations are more likely to co-occur within a substance and be metabolically closely related; metabolic reaction sequences (Caspi et al., 2014) also follow smooth paths in POM despite large jumps in molecular structure. Just as the brain's visual representations have evolved around the natural statistics of light and shapes, the natural statistics of metabolism appear to shape the brain's representation of the olfactory world.
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Affiliation(s)
- Wesley W Qian
- OsmoCambridgeUnited States
- Google Research, Brain TeamCambridgeUnited States
| | | | | | - Brian K Lee
- Google Research, Brain TeamCambridgeUnited States
| | - Yunan Luo
- Department of Computer Science, University of IllinoisUrbanaUnited States
| | | | | | - Jian Peng
- Department of Computer Science, University of IllinoisUrbanaUnited States
| | - Richard C Gerkin
- OsmoCambridgeUnited States
- Google Research, Brain TeamCambridgeUnited States
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4
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Clark JT, Ganguly A, Ejercito J, Luy M, Dahanukar A, Ray A. Chemosensory detection of aversive concentrations of ammonia and basic volatile amines in insects. iScience 2022; 26:105777. [PMID: 36594011 PMCID: PMC9804102 DOI: 10.1016/j.isci.2022.105777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 09/09/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Basic volatiles like ammonia are found in insect environments, and at high concentrations cause an atypical action potential burst, followed by inhibition in multiple classes of olfactory receptor neurons (ORNs) in Drosophila melanogaster. During the period of inhibition, ORNs are unable to fire action potentials to their ligands but continue to display receptor potentials. An increase in calcium is also observed in antennal cells of Drosophila and Aedes aegypti. In the gustatory system, ammonia inhibits sugar and salt responses in a dose-dependent manner. Other amines show similar effects in both gustatory and olfactory neurons, correlated with basicity. The concentrations that inhibit neurons reduce proboscis extension to sucrose in Drosophila. In Aedes, a brief exposure to volatile ammonia abolishes attraction to human skin odor for several minutes. These findings reveal an effect that prevents detection of attractive ligands in the olfactory and gustatory systems and has potential in insect control.
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Affiliation(s)
- Jonathan Trevorrow Clark
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA
| | - Anindya Ganguly
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA
| | - Jadrian Ejercito
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Matthew Luy
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Anupama Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA,Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Anandasankar Ray
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA,Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA,Corresponding author
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5
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Tom MT, Cortés Llorca L, Bucks S, Bisch-Knaden S, Hansson BS. Sex- and tissue-specific expression of chemosensory receptor genes in a hawkmoth. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.976521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
For the nocturnal hawkmoth Manduca sexta, olfactory and gustatory cues are essential for finding partners, food, and oviposition sites. Three chemosensory receptor families, odorant receptors (ORs), ionotropic receptors (IRs), and gustatory receptors (GRs) are involved in the detection of these stimuli. While many chemosensory receptor genes have been identified, knowledge of their expression profile in potentially chemoreceptive organs is incomplete. Here, we studied the expression patterns of chemosensory receptors in different tissues including the antennae, labial palps, proboscis, legs, wings and ovipositor. We compared the receptors’ expression in female and male moths both before and after mating by using the NanoString platform. This tool allowed us to measure expression levels of chemosensory receptor genes in a single reaction using probes designed against 71 OR, 29 IR and 49 GR transcripts. In all tissues investigated, we detected expression of genes from all three receptor families. The highest number of receptors was detected in the antennae (92), followed by the ovipositor (59), while the least number was detected in the hindlegs (21). The highest number of OR genes were expressed in the antennae (63), of which 24 were specific to this main olfactory organ. The highest number of IRs were also expressed in the antennae (16), followed by the ovipositor (15). Likewise, antennae and ovipositor expressed the highest number of GRs (13 and 14). Expression of the OR co-receptor MsexORCo, presumably a prerequisite for OR function, was found in the antennae, labial palps, forelegs and ovipositor. IR co-receptors MsexIR25a and MsexIR76b were expressed across all tested tissues, while expression of the IR co-receptor MsexIR8a was restricted to antennae and ovipositor. Comparing the levels of all 149 transcripts across the nine tested tissues allowed us to identify sex-biased gene expression in the antennae and the legs, two appendages that are also morphologically different between the sexes. However, none of the chemosensory receptors was differentially expressed based on the moths’ mating state. The observed gene expression patterns form a strong base for the functional characterization of chemosensory receptors and the understanding of olfaction and gustation at the molecular level in M. sexta.
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6
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Khan M, Hartmann AH, O’Donnell MP, Piccione M, Pandey A, Chao PH, Dwyer ND, Bargmann CI, Sengupta P. Context-dependent reversal of odorant preference is driven by inversion of the response in a single sensory neuron type. PLoS Biol 2022; 20:e3001677. [PMID: 35696430 PMCID: PMC9232122 DOI: 10.1371/journal.pbio.3001677] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 06/24/2022] [Accepted: 05/16/2022] [Indexed: 11/18/2022] Open
Abstract
The valence and salience of individual odorants are modulated by an animal’s innate preferences, learned associations, and internal state, as well as by the context of odorant presentation. The mechanisms underlying context-dependent flexibility in odor valence are not fully understood. Here, we show that the behavioral response of Caenorhabditis elegans to bacterially produced medium-chain alcohols switches from attraction to avoidance when presented in the background of a subset of additional attractive chemicals. This context-dependent reversal of odorant preference is driven by cell-autonomous inversion of the response to these alcohols in the single AWC olfactory neuron pair. We find that while medium-chain alcohols inhibit the AWC olfactory neurons to drive attraction, these alcohols instead activate AWC to promote avoidance when presented in the background of a second AWC-sensed odorant. We show that these opposing responses are driven via engagement of distinct odorant-directed signal transduction pathways within AWC. Our results indicate that context-dependent recruitment of alternative intracellular signaling pathways within a single sensory neuron type conveys opposite hedonic valences, thereby providing a robust mechanism for odorant encoding and discrimination at the periphery.
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Affiliation(s)
- Munzareen Khan
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Anna H. Hartmann
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Michael P. O’Donnell
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Madeline Piccione
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Anjali Pandey
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Pin-Hao Chao
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Noelle D. Dwyer
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | | | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
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7
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Das Chakraborty S, Chang H, Hansson BS, Sachse S. Higher-order olfactory neurons in the lateral horn support odor valence and odor identity coding in Drosophila. eLife 2022; 11:74637. [PMID: 35621267 PMCID: PMC9142144 DOI: 10.7554/elife.74637] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 05/03/2022] [Indexed: 11/15/2022] Open
Abstract
Understanding neuronal representations of odor-evoked activities and their progressive transformation from the sensory level to higher brain centers features one of the major aims in olfactory neuroscience. Here, we investigated how odor information is transformed and represented in higher-order neurons of the lateral horn, one of the higher olfactory centers implicated in determining innate behavior, using Drosophila melanogaster. We focused on a subset of third-order glutamatergic lateral horn neurons (LHNs) and characterized their odor coding properties in relation to their presynaptic partner neurons, the projection neurons (PNs) by two-photon functional imaging. We show that odors evoke reproducible, stereotypic, and odor-specific response patterns in LHNs. Notably, odor-evoked responses in these neurons are valence-specific in a way that their response amplitude is positively correlated with innate odor preferences. We postulate that this valence-specific activity is the result of integrating inputs from multiple olfactory channels through second-order neurons. GRASP and micro-lesioning experiments provide evidence that glutamatergic LHNs obtain their major excitatory input from uniglomerular PNs, while they receive an odor-specific inhibition through inhibitory multiglomerular PNs. In summary, our study indicates that odor representations in glutamatergic LHNs encode hedonic valence and odor identity and primarily retain the odor coding properties of second-order neurons.
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Affiliation(s)
| | - Hetan Chang
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Silke Sachse
- Research Group Olfactory Coding, Max Planck Institute for Chemical Ecology, Jena, Germany
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8
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Context-dependent control of behavior in Drosophila. Curr Opin Neurobiol 2022; 73:102523. [DOI: 10.1016/j.conb.2022.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/30/2022] [Accepted: 02/02/2022] [Indexed: 12/16/2022]
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Gupta A, Singh SS, Mittal AM, Singh P, Goyal S, Kannan KR, Gupta AK, Gupta N. Mosquito Olfactory Response Ensemble enables pattern discovery by curating a behavioral and electrophysiological response database. iScience 2022; 25:103938. [PMID: 35265812 PMCID: PMC8899409 DOI: 10.1016/j.isci.2022.103938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 12/21/2021] [Accepted: 02/14/2022] [Indexed: 11/12/2022] Open
Abstract
Many experimental studies have examined behavioral and electrophysiological responses of mosquitoes to odors. However, the differences across studies in data collection, processing, and reporting make it difficult to perform large-scale analyses combining data from multiple studies. Here we extract and standardize data for 12 mosquito species, along with Drosophila melanogaster for comparison, from over 170 studies and curate the Mosquito Olfactory Response Ensemble (MORE), publicly available at https://neuralsystems.github.io/MORE. We demonstrate the ability of MORE in generating biological insights by finding patterns across studies. Our analyses reveal that ORs are tuned to specific ranges of several physicochemical properties of odorants; the empty-neuron recording technique for measuring OR responses is more sensitive than the Xenopus oocyte technique; there are systematic differences in the behavioral preferences reported by different types of assays; and odorants tend to become less attractive or more aversive at higher concentrations. MORE is a database of behavioral and electrophysiological responses to odors MORE includes data from 170 studies covering 12 species of mosquitoes along with flies MORE shows differences in odor preferences measured with different assays Empty-neuron technique measures responses more sensitively than the oocyte technique
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10
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Coutinho-Abreu IV, Riffell JA, Akbari OS. Human attractive cues and mosquito host-seeking behavior. Trends Parasitol 2022; 38:246-264. [PMID: 34674963 PMCID: PMC10789295 DOI: 10.1016/j.pt.2021.09.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 12/29/2022]
Abstract
Female mosquitoes use chemical and physical cues, including vision, smell, heat, and humidity, to orient toward hosts. Body odors are produced by skin resident bacteria that convert metabolites secreted in sweat into odorants that confer the characteristic body scent. Mosquitoes detect these compounds using olfactory receptors in their antennal olfactory receptor neurons. Such information is further integrated with the senses of temperature and humidity, as well as vision, processed in the brain into a behavioral output, leading to host finding. Knowledge of human scent components unveils a variety of odorants that are attractive to mosquitoes, but also odor-triggering repellency. Finding ways to divert human-seeking behavior by female mosquitoes using odorants can possibly mitigate mosquito-borne pathogen transmission.
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Affiliation(s)
- Iliano V Coutinho-Abreu
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jeffrey A Riffell
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Omar S Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA.
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11
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Liu F, Chen Z, Ye Z, Liu N. The Olfactory Chemosensation of Hematophagous Hemipteran Insects. Front Physiol 2021; 12:703768. [PMID: 34434117 PMCID: PMC8382127 DOI: 10.3389/fphys.2021.703768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/09/2021] [Indexed: 11/13/2022] Open
Abstract
As one of the most abundant insect orders on earth, most Hemipteran insects are phytophagous, with the few hematophagous exceptions falling into two families: Cimicidae, such as bed bugs, and Reduviidae, such as kissing bugs. Many of these blood-feeding hemipteran insects are known to be realistic or potential disease vectors, presenting both physical and psychological risks for public health. Considerable researches into the interactions between hemipteran insects such as kissing bugs and bed bugs and their human hosts have revealed important information that deepens our understanding of their chemical ecology and olfactory physiology. Sensory mechanisms in the peripheral olfactory system of both insects have now been characterized, with a particular emphasis on their olfactory sensory neurons and odorant receptors. This review summarizes the findings of recent studies of both kissing bugs (including Rhodnius prolixus and Triatoma infestans) and bed bugs (Cimex lectularius), focusing on their chemical ecology and peripheral olfactory systems. Potential chemosensation-based applications for the management of these Hemipteran insect vectors are also discussed.
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Affiliation(s)
- Feng Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States.,Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Zhou Chen
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States.,Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States
| | - Zi Ye
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States.,Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Nannan Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
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12
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Chen Q, Liu X, Cao S, Ma B, Guo M, Shen J, Wang G. Fine Structure and Olfactory Reception of the Labial Palps of Spodoptera frugiperda. Front Physiol 2021; 12:680697. [PMID: 34413785 PMCID: PMC8369160 DOI: 10.3389/fphys.2021.680697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/24/2021] [Indexed: 11/27/2022] Open
Abstract
The olfactory system of insects is essential in many crucial behaviors, such as host seeking, mate recognition, and locating oviposition sites. Lepidopteran moths possess two main olfactory organs, including antennae and labial palps. Compared to antennae, the labial palps are relatively specific and worthy of further investigation due to the labial-palp pit organ (LPO), which contains a large number of sensilla located on the tip segment. The fall armyworm, Spodoptera frugiperda, is a worldwide lepidopteran pest, which can damage more than 350 plants and cause significant economic losses. In this study, we surveyed the structure of the labial palps and LPO of S. frugiperda using a super-high magnification lens zoom 3D microscope. Then, the distribution and fine structure of sensilla located in the LPO of S. frugiperda were investigated using scanning electron microscopy. Subsequently, the electrophysiological responses of labial palps to CO2 and 29 plant volatiles were recorded by using electrolabialpalpography. Our results showed the fine structure of labial palps, the LPO, and the sensilla located in the LPO of S. frugiperda. Moreover, we demonstrated that the labial palps are olfactory organs that respond to both CO2 and other volatile compounds. Our work established a foundation for further study of the roles of labial palps in insect olfactory related behaviors. Further investigations on the function of labial palps and their biological roles together with CO2 and volatile compound responses in S. frugiperda are necessary, as they may provide better insect behavioral regulators for controlling this pest.
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Affiliation(s)
- Qiuyan Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Department of Entomology and MOA Key Laboratory for Monitory and Green Control of Crop Pest, China Agricultural University, Beijing, China
| | - Xiaolan Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Song Cao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Baiwei Ma
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mengbo Guo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Jie Shen
- Department of Entomology and MOA Key Laboratory for Monitory and Green Control of Crop Pest, China Agricultural University, Beijing, China
| | - Guirong Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
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13
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Montell C. Drosophila sensory receptors-a set of molecular Swiss Army Knives. Genetics 2021; 217:1-34. [PMID: 33683373 DOI: 10.1093/genetics/iyaa011] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/17/2020] [Indexed: 01/01/2023] Open
Abstract
Genetic approaches in the fruit fly, Drosophila melanogaster, have led to a major triumph in the field of sensory biology-the discovery of multiple large families of sensory receptors and channels. Some of these families, such as transient receptor potential channels, are conserved from animals ranging from worms to humans, while others, such as "gustatory receptors," "olfactory receptors," and "ionotropic receptors," are restricted to invertebrates. Prior to the identification of sensory receptors in flies, it was widely assumed that these proteins function in just one modality such as vision, smell, taste, hearing, and somatosensation, which includes thermosensation, light, and noxious mechanical touch. By employing a vast combination of genetic, behavioral, electrophysiological, and other approaches in flies, a major concept to emerge is that many sensory receptors are multitaskers. The earliest example of this idea was the discovery that individual transient receptor potential channels function in multiple senses. It is now clear that multitasking is exhibited by other large receptor families including gustatory receptors, ionotropic receptors, epithelial Na+ channels (also referred to as Pickpockets), and even opsins, which were formerly thought to function exclusively as light sensors. Genetic characterizations of these Drosophila receptors and the neurons that express them also reveal the mechanisms through which flies can accurately differentiate between different stimuli even when they activate the same receptor, as well as mechanisms of adaptation, amplification, and sensory integration. The insights gleaned from studies in flies have been highly influential in directing investigations in many other animal models.
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Affiliation(s)
- Craig Montell
- Department of Molecular, Cellular, and Developmental Biology, The Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
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14
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Meng Z, Wang M, Zhao Z, Zhou Y, Wu Y, Guo S, Li M, Zhou Y, Yang S, Li W, Ying B. Development and Validation of a Predictive Model for Severe COVID-19: A Case-Control Study in China. Front Med (Lausanne) 2021; 8:663145. [PMID: 34113636 PMCID: PMC8185163 DOI: 10.3389/fmed.2021.663145] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/12/2021] [Indexed: 02/05/2023] Open
Abstract
Background: Predicting the risk of progression to severe coronavirus disease 2019 (COVID-19) could facilitate personalized diagnosis and treatment options, thus optimizing the use of medical resources. Methods: In this prospective study, 206 patients with COVID-19 were enrolled from regional medical institutions between December 20, 2019, and April 10, 2020. We collated a range of data to derive and validate a predictive model for COVID-19 progression, including demographics, clinical characteristics, laboratory findings, and cytokine levels. Variation analysis, along with the least absolute shrinkage and selection operator (LASSO) and Boruta algorithms, was used for modeling. The performance of the derived models was evaluated by specificity, sensitivity, area under the receiver operating characteristic (ROC) curve (AUC), Akaike information criterion (AIC), calibration plots, decision curve analysis (DCA), and Hosmer–Lemeshow test. Results: We used the LASSO algorithm and logistic regression to develop a model that can accurately predict the risk of progression to severe COVID-19. The model incorporated alanine aminotransferase (ALT), interleukin (IL)-6, expectoration, fatigue, lymphocyte ratio (LYMR), aspartate transaminase (AST), and creatinine (CREA). The model yielded a satisfactory predictive performance with an AUC of 0.9104 and 0.8792 in the derivation and validation cohorts, respectively. The final model was then used to create a nomogram that was packaged into an open-source and predictive calculator for clinical use. The model is freely available online at https://severeconid-19predction.shinyapps.io/SHINY/. Conclusion: In this study, we developed an open-source and free predictive calculator for COVID-19 progression based on ALT, IL-6, expectoration, fatigue, LYMR, AST, and CREA. The validated model can effectively predict progression to severe COVID-19, thus providing an efficient option for early and personalized management and the allocation of appropriate medical resources.
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Affiliation(s)
- Zirui Meng
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Minjin Wang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Zhenzhen Zhao
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Yongzhao Zhou
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Ying Wu
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Shuo Guo
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Mengjiao Li
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Yanbing Zhou
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Shuyu Yang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Weimin Li
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Binwu Ying
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
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15
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Contributions of the Conserved Insect Carbon Dioxide Receptor Subunits to Odor Detection. Cell Rep 2021; 31:107510. [PMID: 32294446 DOI: 10.1016/j.celrep.2020.03.074] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 08/19/2019] [Accepted: 03/23/2020] [Indexed: 01/18/2023] Open
Abstract
The CO2 receptor in mosquitoes is broadly tuned to detect many diverse odorants. The receptor consists of three subunits (Gr1, Gr2, and Gr3) in mosquitoes but only two subunits in Drosophila: Gr21a (Gr1 ortholog) and Gr63a (Gr3 ortholog). We demonstrate that Gr21a is required for CO2 responses in Drosophila, as has been shown for Gr63a. Next, we generate a Drosophila double mutant for Gr21a and Gr63a, and in this background, we functionally express combinations of Aedes Gr1, Gr2, and Gr3 genes in the CO2 empty neuron. Only two subunits, Gr2 and Gr3, suffice for response to CO2. Addition of Gr1 increases sensitivity to CO2, whereas it decreases the response to pyridine. The inhibitory effect of the antagonist isobutyric acid is observed upon addition of Gr1. Gr1 therefore increases the diversity of ligands of the receptor and modulates the response of the receptor complex.
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16
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Arce CC, Theepan V, Schimmel BC, Jaffuel G, Erb M, Machado RA. Plant-associated CO 2 mediates long-distance host location and foraging behaviour of a root herbivore. eLife 2021; 10:65575. [PMID: 33875133 PMCID: PMC8057813 DOI: 10.7554/elife.65575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/08/2021] [Indexed: 11/13/2022] Open
Abstract
Insect herbivores use different cues to locate host plants. The importance of CO2 in this context is not well understood. We manipulated CO2 perception in western corn rootworm (WCR) larvae through RNAi and studied how CO2 perception impacts their interaction with their host plant. The expression of a carbon dioxide receptor, DvvGr2, is specifically required for dose-dependent larval responses to CO2. Silencing CO2 perception or scrubbing plant-associated CO2 has no effect on the ability of WCR larvae to locate host plants at short distances (<9 cm), but impairs host location at greater distances. WCR larvae preferentially orient and prefer plants that grow in well-fertilized soils compared to plants that grow in nutrient-poor soils, a behaviour that has direct consequences for larval growth and depends on the ability of the larvae to perceive root-emitted CO2. This study unravels how CO2 can mediate plant–herbivore interactions by serving as a distance-dependent host location cue. Living deep in the ground and surrounded by darkness, soil insects must rely on the chemicals released by plants to find the roots they feed on. Carbon dioxide, for example, is a by-product of plant respiration, which, above ground, is thought to attract moths to flowers and flies to apples; underground, however, its role is still unclear. This gaseous compound can travel through soil and potentially act as a compass for root-eating insects. Yet, it is also produced by decaying plants or animals, which are not edible. It is therefore possible that insects use this signal as a long-range cue to orient themselves, but then switch to another chemical when closer to their target to narrow in on an actual food source. To test this idea, Arce et al. investigated whether carbon dioxide guides the larvae of Western corn rootworm to maize roots. First, the rootworm genes responsible for sensing carbon dioxide were identified and switched off, making the larvae unable to detect this gas. When the genetically engineered rootworms were further than 9cm from maize roots, they were less able to locate that food source; closer to the roots, however, the insects could orient themselves towards the plant. This suggests that the insects use carbon dioxide at long distances but rely on another chemicals to narrow down their search at close range. To confirm this finding, Arce et al. tried absorbing the carbon dioxide using soda lime, leading to similar effects: carbon dioxide sensitive insects stopped detecting the roots at long but not short distances. Additional experiments then revealed that the compound could help insects find the best roots to feed on. Indeed, eating plants that grow on rich terrain – for instance, fertilized soils – helps insects to grow bigger and faster. These roots also release more carbon dioxide, in turn attracting rootworms more frequently. In the United States and Eastern Europe, Western corn rootworms inflict major damage to crops, highlighting the need to understand and manage the link between fertilization regimes, carbon dioxide release and how these pests find their food.
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Affiliation(s)
- Carla Cm Arce
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Vanitha Theepan
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | | | - Geoffrey Jaffuel
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Matthias Erb
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Ricardo Ar Machado
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,Institute of Plant Sciences, University of Bern, Bern, Switzerland
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17
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Chen ST, Kowalewski J, Ray A. Prolonged activation of carbon dioxide-sensitive neurons in mosquitoes. Interface Focus 2021; 11:20200043. [PMID: 33633836 DOI: 10.1098/rsfs.2020.0043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 11/12/2022] Open
Abstract
Many insects can detect carbon dioxide (CO2) plumes using a conserved receptor made up of members of the gustatory receptor (Gr) family Gr1, Gr2 and Gr3. Mosquitoes are attracted to host animals for blood meals using plumes of CO2 in the exhaled breath using the receptor expressed in the A neuron of the capitate peg sensilla type on the maxillary palps. The receptor is known to also detect several other classes of odorants, including ones emitted from human skin. Here, we discover that a common skin odorant, butyric acid, can cause a phasic activation followed by an unusually prolonged tonic activity after the stimulus is over in the CO2 neurons of mosquitoes. The effect is conserved in both Aedes aegypti and Anopheles gambiae mosquitoes. This raises a question about its role in a mosquito's preference for the skin odour of different individuals. Butyric acid belongs to a small number of odorants known to cause the prolonged activation of the CO2 receptor. A chemical informatic analysis identifies a specific set of physico-chemical features that can be used in a machine learning predictive model for the prolonged activators. Interestingly, this set is different from physico-chemical features selected for activators or inhibitors, indicating that each has a distinct structural basis. The structural understanding opens up an opportunity to find novel ligands to manipulate the CO2 receptor and mosquito behaviour.
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Affiliation(s)
- Stephanie Turner Chen
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA 92521, USA
| | - Joel Kowalewski
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA
| | - Anandasankar Ray
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA 92521, USA.,Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA
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18
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Yang L, Agramonte N, Linthicum KJ, Bloomquist JR. A Survey of Chemoreceptive Responses on Different Mosquito Appendages. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:475-479. [PMID: 32740665 DOI: 10.1093/jme/tjaa154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Indexed: 06/11/2023]
Abstract
Research on the functions of insect chemoreceptors have primarily focused on antennae (olfactory receptors) and mouthparts (gustatory receptors). However, chemoreceptive sensilla are also present on other appendages, such as the leg tarsi and the anterior wing margin, and their specific roles in chemoreception and mosquito behavior remain largely unknown. In this study, electrophysiological analyses in an electroantennogram recording format were performed on Aedes aegypti (L., Diptera: Culicidae) antennae, mouthparts, tarsi, and wings during exposure to a variety of insect repellent and attractant compounds. The results provide evidence that the tarsi and wings can sense chemicals in a gaseous form, and that the odors produce differing responses on different appendages. The most consistent and strongest response occurred when exposed to triethylamine (TEA). Antennae and mouthparts showed nearly identical responses pattern to all tested compounds, and their rank orders of effectiveness were similar to those of fore- and mid-leg tarsi. Hindleg tarsi only responded to TEA, indicating that the hind legs are not as chemoreceptive. Wings responded to a range of odorants, but with a different rank order and voltage amplitude. Insights gleaned into the function of these appendages in insect chemoreception are discussed.
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Affiliation(s)
- Liu Yang
- Neurotoxicology Laboratory, Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL
| | - Natasha Agramonte
- Neurotoxicology Laboratory, Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL
| | - Kenneth J Linthicum
- USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL
| | - Jeffrey R Bloomquist
- Neurotoxicology Laboratory, Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL
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19
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Kowalewski J, Ray A. Predicting Human Olfactory Perception from Activities of Odorant Receptors. iScience 2020; 23:101361. [PMID: 32731170 PMCID: PMC7393469 DOI: 10.1016/j.isci.2020.101361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 05/31/2020] [Accepted: 07/09/2020] [Indexed: 11/30/2022] Open
Abstract
Odor perception in humans is initiated by activation of odorant receptors (ORs) in the nose. However, the ORs linked to specific olfactory percepts are unknown, unlike in vision or taste where receptors are linked to perception of different colors and tastes. The large family of ORs (~400) and multiple receptors activated by an odorant present serious challenges. Here, we first use machine learning to screen ~0.5 million compounds for new ligands and identify enriched structural motifs for ligands of 34 human ORs. We next demonstrate that the activity of ORs successfully predicts many of the 146 different perceptual qualities of chemicals. Although chemical features have been used to model odor percepts, we show that biologically relevant OR activity is often superior. Interestingly, each odor percept could be predicted with very few ORs, implying they contribute more to each olfactory percept. A similar model is observed in Drosophila where comprehensive OR-neuron data are available. Machine learning predicted activity of 34 human ORs for ~0.5 million chemicals Activities of human ORs could predict odor character using machine learning Few OR activities were needed to optimize predictions of each odor percept Behavior predictions in Drosophila also need few olfactory receptor activities
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Affiliation(s)
- Joel Kowalewski
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA
| | - Anandasankar Ray
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA; Department of Molecular, Cell and Systems Biology, University of California, 3401 Watkins Drive, Riverside, CA 92521, USA.
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20
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Charroux B, Daian F, Royet J. Drosophila Aversive Behavior toward Erwinia carotovora carotovora Is Mediated by Bitter Neurons and Leukokinin. iScience 2020; 23:101152. [PMID: 32450516 PMCID: PMC7251953 DOI: 10.1016/j.isci.2020.101152] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 03/02/2020] [Accepted: 05/06/2020] [Indexed: 12/18/2022] Open
Abstract
The phytopathogen Erwinia carotovora carotovora (Ecc) has been used successfully to decipher some of the mechanisms that regulate the interactions between Drosophila melanogaster and bacteria, mostly following forced association between the two species. How do Drosophila normally perceive and respond to the presence of Ecc is unknown. Using a fly feeding two-choice assay and video tracking, we show that Drosophila are first attracted but then repulsed by an Ecc-contaminated solution. The initial attractive phase is dependent on the olfactory Gr63a and Gαq proteins, whereas the second repulsive phase requires a functional gustatory system. Genetic manipulations and calcium imaging indicate that bitter neurons and gustatory receptors Gr66a and Gr33a are needed for the aversive phase and that the neuropeptide leukokinin is also involved. We also demonstrate that these behaviors are independent of the NF-κB cascade that controls some of the immune, metabolic, and behavioral responses to bacteria.
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Affiliation(s)
| | - Fabrice Daian
- Aix-Marseille Université, CNRS, IBDM, Marseille, France
| | - Julien Royet
- Aix-Marseille Université, CNRS, IBDM, Marseille, France.
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21
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Chin SG, Maguire SE, Huoviala P, Jefferis GSXE, Potter CJ. Olfactory Neurons and Brain Centers Directing Oviposition Decisions in Drosophila. Cell Rep 2020; 24:1667-1678. [PMID: 30089274 PMCID: PMC6290906 DOI: 10.1016/j.celrep.2018.07.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 04/30/2018] [Accepted: 07/04/2018] [Indexed: 01/19/2023] Open
Abstract
The sense of smell influences many behaviors, yet how odors are represented in the brain remains unclear. A major challenge to studying olfaction is the lack of methods allowing activation of specific types of olfactory neurons in an ethologically relevant setting. To address this, we developed a genetic method in Drosophila called olfactogenetics in which a narrowly tuned odorant receptor, Or56a, is ectopically expressed in different olfactory neuron types. Stimulation with geosmin (the only known Or56a ligand) in an Or56a mutant background leads to specific activation of only target olfactory neuron types. We used this approach to identify olfactory sensory neurons (OSNs) that directly guide oviposition decisions. We identify 5 OSN-types (Or71a, Or47b, Or49a, Or67b, and Or7a) that, when activated alone, suppress oviposition. Projection neurons partnering with these OSNs share a region of innervation in the lateral horn, suggesting that oviposition site selection might be encoded in this brain region.
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Affiliation(s)
- Sonia G Chin
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Sarah E Maguire
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Paavo Huoviala
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 OQH, UK
| | - Gregory S X E Jefferis
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 OQH, UK
| | - Christopher J Potter
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205, USA.
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22
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Ghaninia M, Majeed S, Dekker T, Hill SR, Ignell R. Hold your breath - Differential behavioral and sensory acuity of mosquitoes to acetone and carbon dioxide. PLoS One 2019; 14:e0226815. [PMID: 31887129 PMCID: PMC6936819 DOI: 10.1371/journal.pone.0226815] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 12/04/2019] [Indexed: 01/16/2023] Open
Abstract
Host seeking in the yellow fever mosquito, Aedes aegypti, and the African malaria mosquito, Anopheles coluzzii, relies on specific and generic host-derived odorants. Previous analyses indicate that the behavioral response of these species depends differentially on the presence of carbon dioxide (CO2) and other constituents in human breath for activation and attraction. In this study, we use a flight tube assay and electrophysiological analysis to assess the role of acetone, a major component of exhaled human breath, in modulating the behavioral and sensory neuronal response of these mosquito species, in the presence and absence of CO2. When presented alone at ecologically relevant concentrations, acetone increases attraction in Ae. aegypti, but not in An. coluzzii. Moreover, in combination with CO2, human breath-equivalents of acetone ranging between 0.1 and 10 ppm reproduces a behavioral response similar to that observed to human breath in host-seeking Ae. aegypti, but not in An. coluzzii. Acetone does, however, reduce attraction to CO2 in An. coluzzii, when presented at a higher concentration of 10 ppm. We identify the capitate peg A neuron of the maxillary palp of both species as a dual detector of CO2 and acetone. The sensory response to acetone, or binary blends of acetone and CO2, reflects the observed behavioral output in both Ae. aegypti and An. coluzzii. We conclude that host recognition is contextual and dependent on a combination of ecologically relevant odorants at naturally occurring concentrations that are encoded, in this case, by differences in the temporal structure of the neuronal response. This information should be considered when designing synthetic blends for that optimally attract mosquitoes for monitoring and control.
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Affiliation(s)
- Majid Ghaninia
- School of Life Sciences, Arizona State University, Tempe, AZ, United States of America
- Division of Entomology, Department of Plant Protection, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Shahid Majeed
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Teun Dekker
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Sharon R. Hill
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Rickard Ignell
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
- * E-mail:
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23
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Human Odour Coding in the Yellow Fever Mosquito, Aedes aegypti. Sci Rep 2019; 9:13336. [PMID: 31527631 PMCID: PMC6746732 DOI: 10.1038/s41598-019-49753-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 08/30/2019] [Indexed: 11/16/2022] Open
Abstract
Insects use their olfactory systems to obtain chemical information on mating partners, oviposition sites and food. The yellow fever mosquito Aedes aegypti, an important vector of human infectious diseases, shows strong preference for human blood meals. This study investigated the chemical basis of host detection by characterizing the neuronal responses of antennal olfactory sensilla of female Ae. aegypti to 103 compounds from human skin emanations. The effect of blood feeding on the responses of olfactory sensilla to these odorants was examined as well. Sensilla SBTII, GP, and three functional subtypes of SST (SST1, SST2, and SST3) responded to most of the compounds tested. Olfactory receptor neurons (ORNs) ‘A’ and ‘B’ in the trichoid sensilla, either activated or inhibited, were involved in the odour coding process. Compounds from different chemical classes elicited responses with different temporal structures and different response patterns across the olfactory sensilla. Except for their increased responses to several odorants, blood-fed mosquitoes generally evoked reduced responses to specific aldehydes, alcohols, aliphatics/aromatics, ketones, and amines through the SST1, SST2, SBTI, SBTII and GP sensilla. The odorants eliciting diminished responses in female mosquitoes after blood feeding may be important in Ae. aegypti host-seeking activity and thus can be candidates for mosquito attractants in the process of this disease vector management.
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24
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Abstract
In this issue of Neuron, MacWilliam et al. (2018) show that the insect carbon dioxide receptor can also detect odorants from different chemical classes, the valence of which is determined by whether they excite or inhibit the sensory neuron.
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Affiliation(s)
- Dieter Wicher
- Department Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-St. 8, 07745 Jena, Germany.
| | - Bill S Hansson
- Department Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-St. 8, 07745 Jena, Germany.
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25
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Mohamed AAM, Retzke T, Das Chakraborty S, Fabian B, Hansson BS, Knaden M, Sachse S. Odor mixtures of opposing valence unveil inter-glomerular crosstalk in the Drosophila antennal lobe. Nat Commun 2019; 10:1201. [PMID: 30867415 PMCID: PMC6416470 DOI: 10.1038/s41467-019-09069-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 02/20/2019] [Indexed: 12/17/2022] Open
Abstract
Evaluating odor blends in sensory processing is a crucial step for signal recognition and execution of behavioral decisions. Using behavioral assays and 2-photon imaging, we have characterized the neural and behavioral correlates of mixture perception in the olfactory system of Drosophila. Mixtures of odors with opposing valences elicit strong inhibition in certain attractant-responsive input channels. This inhibition correlates with reduced behavioral attraction. We demonstrate that defined subsets of GABAergic interneurons provide the neuronal substrate of this computation at pre- and postsynaptic loci via GABAB- and GABAA receptors, respectively. Intriguingly, manipulation of single input channels by silencing and optogenetic activation unveils a glomerulus-specific crosstalk between the attractant- and repellent-responsive circuits. This inhibitory interaction biases the behavioral output. Such a form of selective lateral inhibition represents a crucial neuronal mechanism in the processing of conflicting sensory information.
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Affiliation(s)
- Ahmed A M Mohamed
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Tom Retzke
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Sudeshna Das Chakraborty
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Benjamin Fabian
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Markus Knaden
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany
| | - Silke Sachse
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, 07745, Jena, Germany.
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26
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Coutinho-Abreu IV, Sharma K, Cui L, Yan G, Ray A. Odorant ligands for the CO 2 receptor in two Anopheles vectors of malaria. Sci Rep 2019; 9:2549. [PMID: 30796292 PMCID: PMC6385339 DOI: 10.1038/s41598-019-39099-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 01/08/2019] [Indexed: 01/01/2023] Open
Abstract
Exhaled CO2 is an important host-seeking cue for Anopheles mosquitoes, which is detected by a highly conserved heteromeric receptor consisting of three 7-transmembrane proteins Gr22, Gr23, and Gr24. The CO2 receptor neuron has been shown to also respond sensitively to a variety of odorants in Aedes aegypti. The detection of CO2 is important for upwind navigation and for enhancing the attraction to body heat as well as to skin odorants. The orthologs of the CO2 receptor proteins are present in malaria-transmitting mosquitoes like Anopheles coluzzii and Anopheles sinensis. Activators and inhibitors of the CO2-neuron were tested on the maxillary palps in these two species by single-sensillum electrophysiology. The electrophysiological testing of three prolonged-activator odorants identified originally in Aedes aegypti also showed varying ability to reduce the CO2-ellicited increase in spikes. These findings provide a foundation for comparing the functional conservation with the evolutionary conservation of an important class of odorant receptor. The identification of a suite of natural odorants that can be used to modify the CO2-detection pathway may also contribute to odor-blends that can alter the behavior of these disease transmitting mosquitoes.
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Affiliation(s)
- Iliano V Coutinho-Abreu
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Kavita Sharma
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Liwang Cui
- Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Guiyun Yan
- Public Health and Ecology & Evolution Biology, University of California, Irvine, CA, 92697, USA
| | - Anandasankar Ray
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA.
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Varela N, Gaspar M, Dias S, Vasconcelos ML. Avoidance response to CO2 in the lateral horn. PLoS Biol 2019; 17:e2006749. [PMID: 30653496 PMCID: PMC6336243 DOI: 10.1371/journal.pbio.2006749] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 12/13/2018] [Indexed: 12/16/2022] Open
Abstract
In flies, the olfactory information is carried from the first relay in the brain, the antennal lobe, to the mushroom body (MB) and the lateral horn (LH). Olfactory associations are formed in the MB. The LH was ascribed a role in innate responses based on the stereotyped connectivity with the antennal lobe, stereotyped physiological responses to odors, and MB silencing experiments. Direct evidence for the functional role of the LH is still missing. Here, we investigate the behavioral role of the LH neurons (LHNs) directly, using the CO2 response as a paradigm. Our results show the involvement of the LH in innate responses. Specifically, we demonstrate that activity in two sets of neurons is required for the full behavioral response to CO2. Tests of the behavioral response to other odors indicate the neurons are selective to CO2 response. Using calcium imaging, we observe that the two sets of neurons respond to CO2 in a different manner. Using independent manipulation and recording of the two sets of neurons, we find that the one that projects to the superior intermediate protocerebrum (SIP) also outputs to the local neurons within the LH. The design of simultaneous output at the LH and the SIP, an output of the MB, allows for coordination between innate and learned responses.
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Affiliation(s)
- Nélia Varela
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Miguel Gaspar
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Sophie Dias
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
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28
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Koerte S, Keesey IW, Khallaf MA, Cortés Llorca L, Grosse-Wilde E, Hansson BS, Knaden M. Evaluation of the DREAM Technique for a High-Throughput Deorphanization of Chemosensory Receptors in Drosophila. Front Mol Neurosci 2018; 11:366. [PMID: 30356801 PMCID: PMC6189519 DOI: 10.3389/fnmol.2018.00366] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
In the vinegar fly Drosophila melanogaster, the majority of olfactory receptors mediating the detection of volatile chemicals found in their natural habitat have been functionally characterized (deorphanized) in vivo. In this process, receptors have been assigned ligands leading to either excitation or inhibition in the olfactory sensory neuron where they are expressed. In other, non-drosophilid insect species, scientists have not yet been able to compile datasets about ligand-receptor interactions anywhere near as extensive as in the model organism D. melanogaster, as genetic tools necessary for receptor deorphanization are still missing. Recently, it was discovered that exposure to artificially high concentrations of odorants leads to reliable alterations in mRNA levels of interacting odorant receptors in mammals. Analyzing receptor expression after odorant exposure can, therefore, help to identify ligand-receptor interactions in vivo without the need for other genetic tools. Transfer of the same methodology from mice to a small number of receptors in D. melanogaster resulted in a similar trend, indicating that odorant exposure induced alterations in mRNA levels are generally applicable for deorphanization of interacting chemosensory receptors. Here, we evaluated the potential of the DREAM (Deorphanization of receptors based on expression alterations in mRNA levels) technique for high-throughput deorphanization of chemosensory receptors in insect species using D. melanogaster as a model. We confirmed that in some cases the exposure of a chemosensory receptor to high concentration of its best ligand leads to measureable alterations in mRNA levels. However, unlike in mammals, we found several cases where either confirmed ligands did not induce alterations in mRNA levels of the corresponding chemosensory receptors, or where gene transcript-levels were altered even though there is no evidence for a ligand-receptor interaction. Hence, there are severe limitations to the suitability of the DREAM technique for deorphanization as a general tool to characterize olfactory receptors in insects.
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Affiliation(s)
- Sarah Koerte
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Ian W Keesey
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Mohammed A Khallaf
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Lucas Cortés Llorca
- Department for Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Ewald Grosse-Wilde
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Markus Knaden
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
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