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Sun J, Zhang W, Cui Z, Pan Y, Smagghe G, Zhang L, Wickham JD, Sun J, Mang D. HcGr76 responds to fructose and chlorogenic acid and is involved in regulation of peptide expression in the midgut of Hyphantria cunea larvae. PEST MANAGEMENT SCIENCE 2024. [PMID: 38982883 DOI: 10.1002/ps.8285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/31/2024] [Accepted: 06/20/2024] [Indexed: 07/11/2024]
Abstract
BACKGROUND Sensing dietary components in the gut is important to ensure an appropriate hormonal response and metabolic regulation after food intake. The fall webworm, Hyphantria cunea, is a major invasive pest in China and has led to significant economic losses and ecosystem disruption. The larvae's broad host range and voracious appetite for leaves make H. cunea a primary cause of serious damage to both forests and crops. To date, however, the gustatory receptors (Grs) of H. cunea and their regulatory function remain largely unknown. RESULTS We identified the fall webworm gustatory receptor HcGr76 as a fructose and chlorogenic acid receptor using Ca2+ imaging and determination of intracellular Ca2+ concentration by a microplate reader. Moreover, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis revealed that HcGr76 is highly expressed in the anterior and middle midgut. Knockdown of HcGr76 caused a significant reduction in the expression of neuropeptide F 1 (NPF1) and CCHamide-2, and led to a decrease in carbohydrate and lipid levels in the hemolymph. CONCLUSION Our studies provide circumstantial evidence that HcGr76 expressed in the midgut is involved in sensing dietary components, and regulates the expression of relevant peptide hormones to alter metabolism in H. cunea larvae, thus providing a promising molecular target for the development of new insect-specific control products. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Jing Sun
- College of Life Science, Hebei University, Baoding, China
| | - Wenjing Zhang
- College of Life Science, Hebei University, Baoding, China
| | - Zhebo Cui
- College of Life Science, Hebei University, Baoding, China
| | - Yifan Pan
- College of Life Science, Hebei University, Baoding, China
- Hebei Basic Science Center for Biotic Interaction, Hebei University, Baoding, China
| | - Guy Smagghe
- Institute of Entomology and Special Key Laboratory for Development and Utilization of Insect Resources of Guizhou, Guizhou University, Guiyang, China
- Cellular and Molecular Life Sciences, Department of Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Department of Plants and Crops, Ghent University, Ghent, Belgium
| | - Longwa Zhang
- Anhui Provincial Key Laboratory of Microbial Control, Engineering Research Center of Fungal Biotechnology, Ministry of Education, School of Forestry & Landscape Architecture, Anhui Agricultural University, Hefei, China
| | - Jacob D Wickham
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Jianghua Sun
- College of Life Science, Hebei University, Baoding, China
- Hebei Basic Science Center for Biotic Interaction, Hebei University, Baoding, China
| | - Dingze Mang
- College of Life Science, Hebei University, Baoding, China
- Hebei Basic Science Center for Biotic Interaction, Hebei University, Baoding, China
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
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2
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Kim H, Zhong Z, Cui X, Sung H, Agrawal N, Jiang T, Dus M, Yapici N. HisCl1 regulates gustatory habituation in sweet taste neurons and mediates sugar ingestion in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.592591. [PMID: 38765964 PMCID: PMC11100615 DOI: 10.1101/2024.05.06.592591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Similar to other animals, the fly, Drosophila melanogaster, reduces its responsiveness to tastants with repeated exposure, a phenomenon called gustatory habituation. Previous studies have focused on the circuit basis of gustatory habituation in the fly chemosensory system1,2. However, gustatory neurons reduce their firing rate during repeated stimulation3, suggesting that cell-autonomous mechanisms also contribute to habituation. Here, we used deep learning-based pose estimation and optogenetic stimulation to demonstrate that continuous activation of sweet taste neurons causes gustatory habituation in flies. We conducted a transgenic RNAi screen to identify genes involved in this process and found that knocking down Histamine-gated chloride channel subunit 1 (HisCl1) in the sweet taste neurons significantly reduced gustatory habituation. Anatomical analysis showed that HisCl1 is expressed in the sweet taste neurons of various chemosensory organs. Using single sensilla electrophysiology, we showed that sweet taste neurons reduced their firing rate with prolonged exposure to sucrose. Knocking down HisCl1 in sweet taste neurons suppressed gustatory habituation by reducing the spike frequency adaptation observed in these neurons during high-concentration sucrose stimulation. Finally, we showed that flies lacking HisCl1 in sweet taste neurons increased their consumption of high-concentration sucrose solution at their first meal bout compared to control flies. Together, our results demonstrate that HisCl1 tunes spike frequency adaptation in sweet taste neurons and contributes to gustatory habituation and food intake regulation in flies. Since HisCl1 is highly conserved across many dipteran and hymenopteran species, our findings open a new direction in studying insect gustatory habituation.
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Affiliation(s)
- Haein Kim
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
| | - Ziqing Zhong
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
- Current address: Tianqiao and Chrissy Chen Institute for Neuroscience, California Institute of Technology, Pasadena, CA, USA
| | - Xinyue Cui
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
| | - Hayeon Sung
- Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, MI, USA
| | - Naman Agrawal
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
| | - Tianxing Jiang
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
| | - Monica Dus
- Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, MI, USA
| | - Nilay Yapici
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
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3
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Sang J, Dhakal S, Shrestha B, Nath DK, Kim Y, Ganguly A, Montell C, Lee Y. A single pair of pharyngeal neurons functions as a commander to reject high salt in Drosophila melanogaster. eLife 2024; 12:RP93464. [PMID: 38573740 PMCID: PMC10994663 DOI: 10.7554/elife.93464] [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] [Indexed: 04/05/2024] Open
Abstract
Salt (NaCl), is an essential nutrient for survival, while excessive salt can be detrimental. In the fruit fly, Drosophila melanogaster, internal taste organs in the pharynx are critical gatekeepers impacting the decision to accept or reject a food. Currently, our understanding of the mechanism through which pharyngeal gustatory receptor neurons (GRNs) sense high salt are rudimentary. Here, we found that a member of the ionotropic receptor family, Ir60b, is expressed exclusively in a pair of GRNs activated by high salt. Using a two-way choice assay (DrosoX) to measure ingestion volume, we demonstrate that IR60b and two co-receptors IR25a and IR76b are required to prevent high salt consumption. Mutants lacking external taste organs but retaining the internal taste organs in the pharynx exhibit much higher salt avoidance than flies with all taste organs but missing the three IRs. Our findings highlight the vital role for IRs in a pharyngeal GRN to control ingestion of high salt.
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Affiliation(s)
- Jiun Sang
- Department of Bio and Fermentation Convergence Technology, Kookmin UniversitySeoulRepublic of Korea
| | - Subash Dhakal
- Department of Bio and Fermentation Convergence Technology, Kookmin UniversitySeoulRepublic of Korea
| | - Bhanu Shrestha
- Department of Bio and Fermentation Convergence Technology, Kookmin UniversitySeoulRepublic of Korea
| | - Dharmendra Kumar Nath
- Department of Bio and Fermentation Convergence Technology, Kookmin UniversitySeoulRepublic of Korea
| | - Yunjung Kim
- Department of Bio and Fermentation Convergence Technology, Kookmin UniversitySeoulRepublic of Korea
| | - Anindya Ganguly
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Craig Montell
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin UniversitySeoulRepublic of Korea
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4
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Montanari M, Manière G, Berthelot-Grosjean M, Dusabyinema Y, Gillet B, Grosjean Y, Kurz CL, Royet J. Larval microbiota primes the Drosophila adult gustatory response. Nat Commun 2024; 15:1341. [PMID: 38351056 PMCID: PMC10864365 DOI: 10.1038/s41467-024-45532-4] [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: 03/06/2023] [Accepted: 01/25/2024] [Indexed: 02/16/2024] Open
Abstract
The survival of animals depends, among other things, on their ability to identify threats in their surrounding environment. Senses such as olfaction, vision and taste play an essential role in sampling their living environment, including microorganisms, some of which are potentially pathogenic. This study focuses on the mechanisms of detection of bacteria by the Drosophila gustatory system. We demonstrate that the peptidoglycan (PGN) that forms the cell wall of bacteria triggers an immediate feeding aversive response when detected by the gustatory system of adult flies. Although we identify ppk23+ and Gr66a+ gustatory neurons as necessary to transduce fly response to PGN, we demonstrate that they play very different roles in the process. Time-controlled functional inactivation and in vivo calcium imaging demonstrate that while ppk23+ neurons are required in the adult flies to directly transduce PGN signal, Gr66a+ neurons must be functional in larvae to allow future adults to become PGN sensitive. Furthermore, the ability of adult flies to respond to bacterial PGN is lost when they hatch from larvae reared under axenic conditions. Recolonization of germ-free larvae, but not adults, with a single bacterial species, Lactobacillus brevis, is sufficient to restore the ability of adults to respond to PGN. Our data demonstrate that the genetic and environmental characteristics of the larvae are essential to make the future adults competent to respond to certain sensory stimuli such as PGN.
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Affiliation(s)
| | - Gérard Manière
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRAe, Université Bourgogne, F-21000, Dijon, France
| | - Martine Berthelot-Grosjean
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRAe, Université Bourgogne, F-21000, Dijon, France
| | - Yves Dusabyinema
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR5242, F-69007, Lyon, France
| | - Benjamin Gillet
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR5242, F-69007, Lyon, France
| | - Yaël Grosjean
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRAe, Université Bourgogne, F-21000, Dijon, France
| | - C Léopold Kurz
- Aix-Marseille Université, CNRS, IBDM, Marseille, France.
| | - Julien Royet
- Aix-Marseille Université, CNRS, IBDM, Marseille, France.
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5
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Sang J, Dhakal S, Shrestha B, Nath DK, Kim Y, Ganguly A, Montell C, Lee Y. A single pair of pharyngeal neurons functions as a commander to reject high salt in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.17.562703. [PMID: 37904986 PMCID: PMC10614918 DOI: 10.1101/2023.10.17.562703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Salt is an essential nutrient for survival, while excessive NaCl can be detrimental. In the fruit fly, Drosophila melanogaster, internal taste organs in the pharynx are critical gatekeepers impacting the decision to accept or reject a food. Currently, our understanding of the mechanism through which pharyngeal gustatory receptor neurons (GRNs) sense high salt are rudimentary. Here, we found that a member of the ionotropic receptor family, Ir60b, is expressed exclusively in a pair of GRNs activated by high salt. Using a two-way choice assay (DrosoX) to measure ingestion volume, we demonstrate that IR60b and two coreceptors IR25a and IR76b, are required to prevent high salt consumption. Mutants lacking external taste organs but retaining the internal taste organs in the pharynx exhibit much higher salt avoidance than flies with all taste organs but missing the three IRs. Our findings highlight the vital role for IRs in a pharyngeal GRN to control ingestion of high salt.
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Affiliation(s)
- Jiun Sang
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
- These authors contributed equally
| | - Subash Dhakal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
- These authors contributed equally
| | - Bhanu Shrestha
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Dharmendra Kumar Nath
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Yunjung Kim
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Anindya Ganguly
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA United States
| | - Craig Montell
- Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA United States
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
- Lead Contract
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6
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Chen R, Ai D, Wang G, Wang B. Comparative transcriptome analysis of the antenna and proboscis reveals feeding state-dependent chemosensory genes in Eupeodes corollae. Open Biol 2024; 14:230208. [PMID: 38195061 PMCID: PMC10776234 DOI: 10.1098/rsob.230208] [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: 06/30/2023] [Accepted: 12/11/2023] [Indexed: 01/11/2024] Open
Abstract
The physiological state of an insect can affect its olfactory system. However, the molecular mechanism underlying the effect of nutrition-dependent states on odour-guided behaviours in hoverflies remains unclear. In this study, comparative transcriptome analysis of the antenna and proboscis from Eupeodes corollae under different feeding states was conducted. Compared with the previously published antennal transcriptome, a total of 32 novel chemosensory genes were identified, including 4 ionotropic receptors, 17 gustatory receptors, 9 odorant binding proteins and 2 chemosensory proteins. Analysis of differences in gene expression between different feeding states in male and female antennae and proboscises revealed that the expression levels of chemosensory genes were impacted by feeding state. For instance, the expression levels of EcorOBP19 in female antennae, EcorOBP6 in female proboscis, and EcorOR6, EcorOR14, EcorIR5 and EcorIR84a in male antennae were significantly upregulated after feeding. On the other hand, the expression levels of EcorCSP7 in male proboscis and EcorOR40 in male antennae were significantly downregulated. These findings suggest that nutritional state plays a role in the adaptation of hoverflies' olfactory system to food availability. Overall, our study provides important insights into the plasticity and adaptation of chemosensory systems in hoverflies.
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Affiliation(s)
- Ruipeng Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Dong Ai
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Guirong Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, People’s Republic of China
| | - Bing Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
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7
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Derby CD, Caprio J. What are olfaction and gustation, and do all animals have them? Chem Senses 2024; 49:bjae009. [PMID: 38422390 DOI: 10.1093/chemse/bjae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Indexed: 03/02/2024] Open
Abstract
Different animals have distinctive anatomical and physiological properties to their chemical senses that enhance detection and discrimination of relevant chemical cues. Humans and other vertebrates are recognized as having 2 main chemical senses, olfaction and gustation, distinguished from each other by their evolutionarily conserved neuroanatomical organization. This distinction between olfaction and gustation in vertebrates is not based on the medium in which they live because the most ancestral and numerous vertebrates, the fishes, live in an aquatic habitat and thus both olfaction and gustation occur in water and both can be of high sensitivity. The terms olfaction and gustation have also often been applied to the invertebrates, though not based on homology. Consequently, any similarities between olfaction and gustation in the vertebrates and invertebrates have resulted from convergent adaptations or shared constraints during evolution. The untidiness of assigning olfaction and gustation to invertebrates has led some to recommend abandoning the use of these terms and instead unifying them and others into a single category-chemical sense. In our essay, we compare the nature of the chemical senses of diverse animal types and consider their designation as olfaction, oral gustation, extra-oral gustation, or simply chemoreception. Properties that we have found useful in categorizing chemical senses of vertebrates and invertebrates include the nature of peripheral sensory cells, organization of the neuropil in the processing centers, molecular receptor specificity, and function.
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Affiliation(s)
- Charles D Derby
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - John Caprio
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States
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8
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Chiang MH, Lin YC, Wu T, Wu CL. Thermosensation and Temperature Preference: From Molecules to Neuronal Circuits in Drosophila. Cells 2023; 12:2792. [PMID: 38132112 PMCID: PMC10741703 DOI: 10.3390/cells12242792] [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: 11/02/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Temperature has a significant effect on all physiological processes of animals. Suitable temperatures promote responsiveness, movement, metabolism, growth, and reproduction in animals, whereas extreme temperatures can cause injury or even death. Thus, thermosensation is important for survival in all animals. However, mechanisms regulating thermosensation remain unexplored, mostly because of the complexity of mammalian neural circuits. The fruit fly Drosophila melanogaster achieves a desirable body temperature through ambient temperature fluctuations, sunlight exposure, and behavioral strategies. The availability of extensive genetic tools and resources for studying Drosophila have enabled scientists to unravel the mechanisms underlying their temperature preference. Over the past 20 years, Drosophila has become an ideal model for studying temperature-related genes and circuits. This review provides a comprehensive overview of our current understanding of thermosensation and temperature preference in Drosophila. It encompasses various aspects, such as the mechanisms by which flies sense temperature, the effects of internal and external factors on temperature preference, and the adaptive strategies employed by flies in extreme-temperature environments. Understanding the regulating mechanisms of thermosensation and temperature preference in Drosophila can provide fundamental insights into the underlying molecular and neural mechanisms that control body temperature and temperature-related behavioral changes in other animals.
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Affiliation(s)
- Meng-Hsuan Chiang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan; (M.-H.C.); (Y.-C.L.)
| | - Yu-Chun Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan; (M.-H.C.); (Y.-C.L.)
| | - Tony Wu
- Department of Neurology, New Taipei Municipal TuCheng Hospital, Chang Gung Memorial Hospital, New Taipei City 23652, Taiwan;
| | - Chia-Lin Wu
- Department of Neurology, New Taipei Municipal TuCheng Hospital, Chang Gung Memorial Hospital, New Taipei City 23652, Taiwan;
- Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
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9
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Jelen M, Musso PY, Junca P, Gordon MD. Optogenetic induction of appetitive and aversive taste memories in Drosophila. eLife 2023; 12:e81535. [PMID: 37750673 PMCID: PMC10561975 DOI: 10.7554/elife.81535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/22/2023] [Indexed: 09/27/2023] Open
Abstract
Tastes typically evoke innate behavioral responses that can be broadly categorized as acceptance or rejection. However, research in Drosophila melanogaster indicates that taste responses also exhibit plasticity through experience-dependent changes in mushroom body circuits. In this study, we develop a novel taste learning paradigm using closed-loop optogenetics. We find that appetitive and aversive taste memories can be formed by pairing gustatory stimuli with optogenetic activation of sensory neurons or dopaminergic neurons encoding reward or punishment. As with olfactory memories, distinct dopaminergic subpopulations drive the parallel formation of short- and long-term appetitive memories. Long-term memories are protein synthesis-dependent and have energetic requirements that are satisfied by a variety of caloric food sources or by direct stimulation of MB-MP1 dopaminergic neurons. Our paradigm affords new opportunities to probe plasticity mechanisms within the taste system and understand the extent to which taste responses depend on experience.
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Affiliation(s)
- Meghan Jelen
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
| | - Pierre-Yves Musso
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
| | - Pierre Junca
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
| | - Michael D Gordon
- Department of Zoology and Life Sciences Institute, University of British ColumbiaVancouverCanada
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10
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Pradhan RN, Shrestha B, Lee Y. Molecular Basis of Hexanoic Acid Taste in Drosophila melanogaster. Mol Cells 2023; 46:451-460. [PMID: 37202372 PMCID: PMC10336273 DOI: 10.14348/molcells.2023.0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/28/2023] [Accepted: 04/10/2023] [Indexed: 05/20/2023] Open
Abstract
Animals generally prefer nutrients and avoid toxic and harmful chemicals. Recent behavioral and physiological studies have identified that sweet-sensing gustatory receptor neurons (GRNs) in Drosophila melanogaster mediate appetitive behaviors toward fatty acids. Sweet-sensing GRN activation requires the function of the ionotropic receptors IR25a, IR56d, and IR76b, as well as the gustatory receptor GR64e. However, we reveal that hexanoic acid (HA) is toxic rather than nutritious to D. melanogaster. HA is one of the major components of the fruit Morinda citrifolia (noni). Thus, we analyzed the gustatory responses to one of major noni fatty acids, HA, via electrophysiology and proboscis extension response (PER) assay. Electrophysiological tests show this is reminiscent of arginine-mediated neuronal responses. Here, we determined that a low concentration of HA induced attraction, which was mediated by sweet-sensing GRNs, and a high concentration of HA induced aversion, which was mediated by bitter-sensing GRNs. We also demonstrated that a low concentration of HA elicits attraction mainly mediated by GR64d and IR56d expressed by sweet-sensing GRNs, but a high concentration of HA activates three gustatory receptors (GR32a, GR33a, and GR66a) expressed by bitter-sensing GRNs. The mechanism of sensing HA is biphasic in a dose dependent manner. Furthermore, HA inhibit sugar-mediated activation like other bitter compounds. Taken together, we discovered a binary HA-sensing mechanism that may be evolutionarily meaningful in the foraging niche of insects.
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Affiliation(s)
| | - Bhanu Shrestha
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
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11
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Shrestha B, Aryal B, Lee Y. The taste of vitamin C in Drosophila. EMBO Rep 2023; 24:e56319. [PMID: 37114473 PMCID: PMC10240197 DOI: 10.15252/embr.202256319] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 04/04/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Vitamins are essential micronutrients, but the mechanisms of vitamin chemoreception in animals are poorly understood. Here, we provide evidence that vitamin C doubles starvation resistance and induces egg laying in Drosophila melanogaster. Our behavioral analyses of genetically engineered and anatomically ablated flies show that fruit flies sense vitamin C via sweet-sensing gustatory receptor neurons (GRNs) in the labellum. Using a behavioral screen and in vivo electrophysiological analyses of ionotropic receptors (IRs) and sweet-sensing gustatory receptors (GRs), we find that two broadly tuned IRs (i.e., IR25a and IR76b) and five GRs (i.e., GR5a, GR61a, GR64b, GR64c, and GR64e) are essential for vitamin C detection. Thus, vitamin C is directly detected by the fly labellum and requires at least two distinct receptor types. Next, we expand our electrophysiological study to test attractive tastants such as sugars, carboxylic acids, and glycerol. Our analysis elucidates the molecular basis of chemoreception in sweet-sensing GRNs.
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Affiliation(s)
- Bhanu Shrestha
- Department of Bio & Fermentation Convergence TechnologyKookmin UniversitySeoulKorea
| | - Binod Aryal
- Department of Bio & Fermentation Convergence TechnologyKookmin UniversitySeoulKorea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence TechnologyKookmin UniversitySeoulKorea
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12
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Shiu PK, Sterne GR, Spiller N, Franconville R, Sandoval A, Zhou J, Simha N, Kang CH, Yu S, Kim JS, Dorkenwald S, Matsliah A, Schlegel P, Szi-chieh Y, McKellar CE, Sterling A, Costa M, Eichler K, Jefferis GS, Murthy M, Bates AS, Eckstein N, Funke J, Bidaye SS, Hampel S, Seeds AM, Scott K. A leaky integrate-and-fire computational model based on the connectome of the entire adult Drosophila brain reveals insights into sensorimotor processing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.02.539144. [PMID: 37205514 PMCID: PMC10187186 DOI: 10.1101/2023.05.02.539144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The forthcoming assembly of the adult Drosophila melanogaster central brain connectome, containing over 125,000 neurons and 50 million synaptic connections, provides a template for examining sensory processing throughout the brain. Here, we create a leaky integrate-and-fire computational model of the entire Drosophila brain, based on neural connectivity and neurotransmitter identity, to study circuit properties of feeding and grooming behaviors. We show that activation of sugar-sensing or water-sensing gustatory neurons in the computational model accurately predicts neurons that respond to tastes and are required for feeding initiation. Computational activation of neurons in the feeding region of the Drosophila brain predicts those that elicit motor neuron firing, a testable hypothesis that we validate by optogenetic activation and behavioral studies. Moreover, computational activation of different classes of gustatory neurons makes accurate predictions of how multiple taste modalities interact, providing circuit-level insight into aversive and appetitive taste processing. Our computational model predicts that the sugar and water pathways form a partially shared appetitive feeding initiation pathway, which our calcium imaging and behavioral experiments confirm. Additionally, we applied this model to mechanosensory circuits and found that computational activation of mechanosensory neurons predicts activation of a small set of neurons comprising the antennal grooming circuit that do not overlap with gustatory circuits, and accurately describes the circuit response upon activation of different mechanosensory subtypes. Our results demonstrate that modeling brain circuits purely from connectivity and predicted neurotransmitter identity generates experimentally testable hypotheses and can accurately describe complete sensorimotor transformations.
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Affiliation(s)
- Philip K. Shiu
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Gabriella R. Sterne
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
- University of Rochester Medical Center, Department of Biomedical Genetics
| | - Nico Spiller
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | | | - Andrea Sandoval
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Joie Zhou
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Neha Simha
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Chan Hyuk Kang
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Seongbong Yu
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Jinseop S. Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Sven Dorkenwald
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
- Computer Science Department, Princeton University, Princeton, NJ, USA
| | - Arie Matsliah
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Philipp Schlegel
- Department of Zoology, University of Cambridge
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge
| | - Yu Szi-chieh
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Claire E. McKellar
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Amy Sterling
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Marta Costa
- Department of Zoology, University of Cambridge
| | | | - Gregory S.X.E. Jefferis
- Department of Zoology, University of Cambridge
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge
| | - Mala Murthy
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Alexander Shakeel Bates
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge
- Centre for Neural Circuits and Behaviour, The University of Oxford
- Department of Neurobiology and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | | | - Jan Funke
- HHMI Janelia Research Campus, Ashburn, USA
| | - Salil S. Bidaye
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Stefanie Hampel
- Institute of Neurobiology, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico
| | - Andrew M. Seeds
- Institute of Neurobiology, University of Puerto Rico-Medical Sciences Campus, San Juan, Puerto Rico
| | - Kristin Scott
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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13
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Benton R, Dahanukar A. Chemosensory Coding in Drosophila Single Sensilla. Cold Spring Harb Protoc 2023; 2023:107803-pdb.top. [PMID: 36446528 DOI: 10.1101/pdb.top107803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The chemical senses-smell and taste-detect and discriminate an enormous diversity of environmental stimuli and provide fascinating but challenging models to investigate how sensory cues are represented in the brain. Important stimulus-coding events occur in peripheral sensory neurons, which express specific combinations of chemosensory receptors with defined ligand-response profiles. These receptors convert ligand recognition into spatial and temporal patterns of neural activity that are transmitted to, and interpreted in, central brain regions. Drosophila melanogaster provides an attractive model to study chemosensory coding because it possesses relatively simple peripheral olfactory and gustatory systems that display many organizational parallels to those of vertebrates. Moreover, nearly all peripheral chemosensory neurons have been molecularly characterized and are accessible for physiological analysis, as they are exposed on the surface of sensory organs housed in specialized hairs called sensilla. Here, we briefly review anatomical, molecular, and physiological properties of adult Drosophila olfactory and gustatory systems and provide background to methods for electrophysiological recordings of ligand-evoked activity from different types of chemosensory sensilla.
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Affiliation(s)
- Richard Benton
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Anupama Dahanukar
- Department of Molecular, Cell & Systems Biology, University of California, Riverside, California 92521, USA
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14
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Mang D, Toyama T, Yamagishi T, Sun J, Purba ER, Endo H, Matthews MM, Ito K, Nagata S, Sato R. Dietary compounds activate an insect gustatory receptor on enteroendocrine cells to elicit myosuppressin secretion. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 155:103927. [PMID: 36871864 DOI: 10.1016/j.ibmb.2023.103927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 03/01/2023] [Accepted: 03/01/2023] [Indexed: 05/10/2023]
Abstract
Sensing of midgut internal contents is important for ensuring appropriate hormonal response and digestion following the ingestion of dietary components. Studies in mammals have demonstrated that taste receptors (TRs), a subgroup of G protein-coupled receptors (GPCRs), are expressed in gut enteroendocrine cells (EECs) to sense dietary compounds and regulate the production and/or secretion of peptide hormones. Although progress has been made in identifying expression patterns of gustatory receptors (GRs) in gut EECs, it is currently unknown whether these receptors, which act as ligand-gated ion channels, serve similar functions as mammalian GPCR TRs to elicit hormone production and/or secretion. A Bombyx mori Gr, BmGr6, has been demonstrated to express in cells by oral sensory organs, midgut and nervous system; and to sense isoquercitrin and chlorogenic acid, which are non-nutritional secondary metabolites of host mulberry. Here, we show that BmGr6 co-expresses with Bommo-myosuppressin (BMS) in midgut EECs, responds to dietary compounds and is involved in regulation of BMS secretion. The presence of dietary compounds in midgut lumen after food intake resulted in an increase of BMS secretions in hemolymph of both wild-type and BmGr9 knockout larvae, but BMS secretions in BmGr6 knockout larvae decreased relative to wild-type. In addition, loss of BmGr6 led to a significant decrease in weight gain, excrement, hemolymph carbohydrates levels and hemolymph lipid levels. Interestingly, although BMS is produced in both midgut EECs and brain neurosecretory cells (NSCs), BMS levels in tissue extracts suggested that the increase in hemolymph BMS during feeding conditions is primarily due to secretion from midgut EECs. Our studies indicate that BmGr6 expressed in midgut EECs responds to the presence of dietary compounds in the lumen by eliciting BMS secretion in B. mori larvae.
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Affiliation(s)
- Dingze Mang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China; Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan.
| | - Tomoko Toyama
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan
| | - Takayuki Yamagishi
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan
| | - Jing Sun
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China
| | - Endang R Purba
- Structural Cellular Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Haruka Endo
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan
| | - Melissa M Matthews
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Katsuhiko Ito
- Department of Science of Biological Production, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Shinji Nagata
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Ryoichi Sato
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan.
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15
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King BH, Gunathunga PB. Gustation in insects: taste qualities and types of evidence used to show taste function of specific body parts. JOURNAL OF INSECT SCIENCE (ONLINE) 2023; 23:11. [PMID: 37014302 PMCID: PMC10072106 DOI: 10.1093/jisesa/iead018] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/03/2023] [Accepted: 03/10/2023] [Indexed: 06/19/2023]
Abstract
The insect equivalent of taste buds are gustatory sensilla, which have been found on mouthparts, pharynxes, antennae, legs, wings, and ovipositors. Most gustatory sensilla are uniporous, but not all apparently uniporous sensilla are gustatory. Among sensilla containing more than one neuron, a tubular body on one dendrite is also indicative of a taste sensillum, with the tubular body adding tactile function. But not all taste sensilla are also tactile. Additional morphological criteria are often used to recognize if a sensillum is gustatory. Further confirmation of such criteria by electrophysiological or behavioral evidence is needed. The five canonical taste qualities to which insects respond are sweet, bitter, sour, salty, and umami. But not all tastants that insects respond to easily fit in these taste qualities. Categories of insect tastants can be based not only on human taste perception, but also on whether the response is deterrent or appetitive and on chemical structure. Other compounds that at least some insects taste include, but are not limited to: water, fatty acids, metals, carbonation, RNA, ATP, pungent tastes as in horseradish, bacterial lipopolysaccharides, and contact pheromones. We propose that, for insects, taste be defined not only as a response to nonvolatiles but also be restricted to responses that are, or are thought to be, mediated by a sensillum. This restriction is useful because some of the receptor proteins in gustatory sensilla are also found elsewhere.
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16
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Molecular sensors in the taste system of Drosophila. Genes Genomics 2023; 45:693-707. [PMID: 36828965 DOI: 10.1007/s13258-023-01370-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 02/08/2023] [Indexed: 02/26/2023]
Abstract
BACKGROUND Most animals, including humans and insects, consume foods based on their senses. Feeding is mostly regulated by taste and smell. Recent insect studies shed insight into the cross-talk between taste and smell, sweetness and temperature, sweetness and texture, and other sensory modality pairings. Five canonical tastes include sweet, umami, bitter, salty, and sour. Furthermore, other receptors that mediate the detection of noncanonical sensory attributes encoded by taste stimuli, such as Ca2+, Zn2+, Cu2+, lipid, and carbonation, have been characterized. Deorphanizing receptors and interactions among different modalities are expanding the taste field. METHODS Our study explores the taste system of Drosophila melanogaster and perception processing in insects to broaden the neuroscience of taste. Attractive and aversive taste cues and their chemoreceptors are categorized as tables. In addition, we summarize the recent progress in animal behavior as affected by the integration of multisensory information in relation to different gustatory receptor neuronal activations, olfaction, texture, and temperature. We mainly focus on peripheral responses and insect decision-making. CONCLUSION Drosophila is an excellent model animal to study the cellular and molecular mechanism of the taste system. Despite the divergence in the receptors to detect chemicals, taste research in the fruit fly can offer new insights into the many different taste sensors of animals and how to test the interaction among different sensory modalities.
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17
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Abstract
Salt taste, the taste of sodium chloride (NaCl), is mechanistically one of the most complex and puzzling among basic tastes. Sodium has essential functions in the body but causes harm in excess. Thus, animals use salt taste to ingest the right amount of salt, which fluctuates by physiological needs: typically, attraction to low salt concentrations and rejection of high salt. This concentration-valence relationship is universally observed in terrestrial animals, and research has revealed complex peripheral codes for NaCl involving multiple taste pathways of opposing valence. Sodium-dependent and -independent pathways mediate attraction and aversion to NaCl, respectively. Gustatory sensors and cells that transduce NaCl have been uncovered, along with downstream signal transduction and neurotransmission mechanisms. However, much remains unknown. This article reviews classical and recent advances in our understanding of the molecular and cellular mechanisms underlying salt taste in mammals and insects and discusses perspectives on human salt taste.
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Affiliation(s)
- Akiyuki Taruno
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan; .,Japan Science and Technology Agency, CREST, Saitama, Japan
| | - Michael D Gordon
- Department of Zoology and Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
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18
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Reisenman CE, Wong J, Vedagarbha N, Livelo C, Scott K. Taste adaptations associated with host specialization in the specialist Drosophila sechellia. J Exp Biol 2023; 226:jeb244641. [PMID: 36637369 PMCID: PMC10088416 DOI: 10.1242/jeb.244641] [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: 06/08/2022] [Accepted: 01/09/2023] [Indexed: 01/14/2023]
Abstract
Chemosensory-driven host plant specialization is a major force mediating insect ecological adaptation and speciation. Drosophila sechellia, a species endemic to the Seychelles islands, feeds and oviposits on Morinda citrifolia almost exclusively. This fruit is harmless to D. sechellia but toxic to other Drosophilidae, including the closely related generalists D. simulans and D. melanogaster, because of its high content of fatty acids. While several olfactory adaptations mediating D. sechellia's preference for its host have been uncovered, the role of taste has been much less examined. We found that D. sechellia has reduced taste and feeding aversion to bitter compounds and host fatty acids that are aversive to D. melanogaster and D. simulans. The loss of aversion to canavanine, coumarin and fatty acids arose in the D. sechellia lineage, as its sister species D. simulans showed responses akin to those of D. melanogaster. Drosophila sechellia has increased taste and feeding responses towards M. citrifolia. These results are in line with D. sechellia's loss of genes that encode bitter gustatory receptors (GRs) in D. melanogaster. We found that two GR genes which are lost in D. sechellia, GR39a.a and GR28b.a, influence the reduction of aversive responses to some bitter compounds. Also, D. sechellia has increased appetite for a prominent host fatty acid compound that is toxic to its relatives. Our results support the hypothesis that changes in the taste system, specifically a reduction of sensitivity to bitter compounds that deter generalist ancestors, contribute to the specialization of D. sechellia for its host.
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Affiliation(s)
- Carolina E. Reisenman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
- Essig Museum of Entomology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Joshua Wong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Namrata Vedagarbha
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | | | - Kristin Scott
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
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19
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Yu J, Guo X, Zheng S, Zhang W. A dedicate sensorimotor circuit enables fine texture discrimination by active touch. PLoS Genet 2023; 19:e1010562. [PMID: 36649336 PMCID: PMC9882754 DOI: 10.1371/journal.pgen.1010562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 01/27/2023] [Accepted: 12/08/2022] [Indexed: 01/18/2023] Open
Abstract
Active touch facilitates environments exploration by voluntary, self-generated movements. However, the neural mechanisms underlying sensorimotor control for active touch are poorly understood. During foraging and feeding, Drosophila gather information on the properties of food (texture, hardness, taste) by constant probing with their proboscis. Here we identify a group of neurons (sd-L neurons) on the fly labellum that are mechanosensitive to labellum displacement and synapse onto the sugar-sensing neurons via axo-axonal synapses to induce preference to harder food. These neurons also feed onto the motor circuits that control proboscis extension and labellum spreading to provide on-line sensory feedback critical for controlling the probing processes, thus facilitating ingestion of less liquified food. Intriguingly, this preference was eliminated in mated female flies, reflecting an elevated need for softer food. Our results propose a sensorimotor circuit composed of mechanosensory, gustatory and motor neurons that enables the flies to select ripe yet not over-rotten food by active touch.
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Affiliation(s)
- Jie Yu
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Xuan Guo
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Shen Zheng
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Wei Zhang
- School of Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- * E-mail:
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20
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Değirmenci L, Rogé Ferreira FL, Vukosavljevic A, Heindl C, Keller A, Geiger D, Scheiner R. Sugar perception in honeybees. Front Physiol 2023; 13:1089669. [PMID: 36714315 PMCID: PMC9880324 DOI: 10.3389/fphys.2022.1089669] [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: 11/08/2022] [Accepted: 12/28/2022] [Indexed: 01/14/2023] Open
Abstract
Honeybees (Apis mellifera) need their fine sense of taste to evaluate nectar and pollen sources. Gustatory receptors (Grs) translate taste signals into electrical responses. In vivo experiments have demonstrated collective responses of the whole Gr-set. We here disentangle the contributions of all three honeybee sugar receptors (AmGr1-3), combining CRISPR/Cas9 mediated genetic knock-out, electrophysiology and behaviour. We show an expanded sugar spectrum of the AmGr1 receptor. Mutants lacking AmGr1 have a reduced response to sucrose and glucose but not to fructose. AmGr2 solely acts as co-receptor of AmGr1 but not of AmGr3, as we show by electrophysiology and using bimolecular fluorescence complementation. Our results show for the first time that AmGr2 is indeed a functional receptor on its own. Intriguingly, AmGr2 mutants still display a wildtype-like sugar taste. AmGr3 is a specific fructose receptor and is not modulated by a co-receptor. Eliminating AmGr3 while preserving AmGr1 and AmGr2 abolishes the perception of fructose but not of sucrose. Our comprehensive study on the functions of AmGr1, AmGr2 and AmGr3 in honeybees is the first to combine investigations on sugar perception at the receptor level and simultaneously in vivo. We show that honeybees rely on two gustatory receptors to sense all relevant sugars.
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Affiliation(s)
- Laura Değirmenci
- Behavioral Physiology and Sociobiology, Biocenter, Julius-Maximilians-Universität Würzburg, Wuerzburg, Germany,*Correspondence: Laura Değirmenci, ; Fabio Luiz Rogé Ferreira,
| | - Fabio Luiz Rogé Ferreira
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Julius-Maximilians-Universität Würzburg, Wuerzburg, Germany,*Correspondence: Laura Değirmenci, ; Fabio Luiz Rogé Ferreira,
| | - Adrian Vukosavljevic
- Behavioral Physiology and Sociobiology, Biocenter, Julius-Maximilians-Universität Würzburg, Wuerzburg, Germany
| | - Cornelia Heindl
- Behavioral Physiology and Sociobiology, Biocenter, Julius-Maximilians-Universität Würzburg, Wuerzburg, Germany
| | - Alexander Keller
- Organismic and Cellular Interactions, Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Dietmar Geiger
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Julius-Maximilians-Universität Würzburg, Wuerzburg, Germany
| | - Ricarda Scheiner
- Behavioral Physiology and Sociobiology, Biocenter, Julius-Maximilians-Universität Würzburg, Wuerzburg, Germany
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21
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Dey M, Ganguly A, Dahanukar A. An inhibitory mechanism for suppressing high salt intake in Drosophila. Chem Senses 2023; 48:bjad014. [PMID: 37201555 PMCID: PMC10413321 DOI: 10.1093/chemse/bjad014] [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: 08/15/2022] [Indexed: 05/20/2023] Open
Abstract
High concentrations of dietary salt are harmful to health. Like most animals, Drosophila melanogaster are attracted to foods that have low concentrations of salt, but show strong taste avoidance of high salt foods. Salt in known on multiple classes of taste neurons, activating Gr64f sweet-sensing neurons that drive food acceptance and 2 others (Gr66a bitter and Ppk23 high salt) that drive food rejection. Here we find that NaCl elicits a bimodal dose-dependent response in Gr64f taste neurons, which show high activity with low salt and depressed activity with high salt. High salt also inhibits the sugar response of Gr64f neurons, and this action is independent of the neuron's taste response to salt. Consistent with the electrophysiological analysis, feeding suppression in the presence of salt correlates with inhibition of Gr64f neuron activity, and remains if high salt taste neurons are genetically silenced. Other salts such as Na2SO4, KCl, MgSO4, CaCl2, and FeCl3 act on sugar response and feeding behavior in the same way. A comparison of the effects of various salts suggests that inhibition is dictated by the cationic moiety rather than the anionic component of the salt. Notably, high salt-dependent inhibition is not observed in Gr66a neurons-response to a canonical bitter tastant, denatonium, is not altered by high salt. Overall, this study characterizes a mechanism in appetitive Gr64f neurons that can deter ingestion of potentially harmful salts.
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Affiliation(s)
- Manali Dey
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, United States
| | - Anindya Ganguly
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, United States
| | - Anupama Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, United States
- Department of Molecular, Cell & Systems Biology, University of California, Riverside, CA 92521, United States
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22
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Snell NJ, Fisher JD, Hartmann GG, Zolyomi B, Talay M, Barnea G. Complex representation of taste quality by second-order gustatory neurons in Drosophila. Curr Biol 2022; 32:3758-3772.e4. [PMID: 35973432 PMCID: PMC9474709 DOI: 10.1016/j.cub.2022.07.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 04/08/2022] [Accepted: 07/19/2022] [Indexed: 01/24/2023]
Abstract
Sweet and bitter compounds excite different sensory cells and drive opposing behaviors. However, it remains unclear how sweet and bitter tastes are represented by the neural circuits linking sensation to behavior. To investigate this question in Drosophila, we devised trans-Tango(activity), a strategy for calcium imaging of second-order gustatory projection neurons based on trans-Tango, a genetic transsynaptic tracing technique. We found spatial overlap between the projection neuron populations activated by sweet and bitter tastants. The spatial representation of bitter tastants in the projection neurons was consistent, while that of sweet tastants was heterogeneous. Furthermore, we discovered that bitter tastants evoke responses in the gustatory receptor neurons and projection neurons upon both stimulus onset and offset and that bitter offset and sweet onset excite overlapping second-order projections. These findings demonstrate an unexpected complexity in the representation of sweet and bitter tastants by second-order neurons of the gustatory circuit.
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Affiliation(s)
- Nathaniel J Snell
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA; The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - John D Fisher
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA; The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Griffin G Hartmann
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA; The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Bence Zolyomi
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA; The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Mustafa Talay
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA; The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA
| | - Gilad Barnea
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA; The Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA.
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23
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McDowell SAT, Stanley M, Gordon MD. A molecular mechanism for high salt taste in Drosophila. Curr Biol 2022; 32:3070-3081.e5. [PMID: 35772408 DOI: 10.1016/j.cub.2022.06.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/04/2022] [Accepted: 06/07/2022] [Indexed: 11/25/2022]
Abstract
Dietary salt detection and consumption are crucial to maintaining fluid and ionic homeostasis. To optimize salt intake, animals employ salt-dependent activation of multiple taste pathways. Generally, sodium activates attractive taste cells, but attraction is overridden at high salt concentrations by cation non-selective activation of aversive taste cells. In flies, high salt avoidance is driven by both "bitter" taste neurons and a class of glutamatergic "high salt" neurons expressing pickpocket23 (ppk23). Although the cellular basis of salt taste has been described, many of the molecular mechanisms remain elusive. Here, we show that ionotropic receptor 7c (IR7c) is expressed in glutamatergic high salt neurons, where it functions with co-receptors IR76b and IR25a to detect high salt and is essential for monovalent salt taste. Misexpression of IR7c in sweet neurons, which endogenously express IR76b and IR25a, confers responsiveness to non-sodium salts, indicating that IR7c is sufficient to convert a sodium-selective gustatory receptor neuron to a cation non-selective one. Furthermore, the resultant transformation of taste neuron tuning switches potassium chloride from an aversive to an attractive tastant. This research provides insight into the molecular basis of monovalent and divalent salt-taste coding.
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Affiliation(s)
- Sasha A T McDowell
- Department of Zoology and Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Molly Stanley
- Department of Zoology and Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Michael D Gordon
- Department of Zoology and Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Parkinson RH, Kessler SC, Scott J, Simpson A, Bu J, Al-Esawy M, Mahdi A, Miriyala A, Wright GA. Temporal responses of bumblebee gustatory neurons to sugars. iScience 2022; 25:104499. [PMID: 35733788 PMCID: PMC9207677 DOI: 10.1016/j.isci.2022.104499] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/19/2022] [Accepted: 05/26/2022] [Indexed: 11/05/2022] Open
Abstract
The sense of taste permits the recognition of valuable nutrients and the avoidance of potential toxins. Previously, we found that bumblebees have a specialized mechanism for sensing sugars whereby two gustatory receptor neurons (GRNs) within the galeal sensilla of the bees’ mouthparts exhibit bursts of spikes. Here, we show that the temporal firing patterns of these GRNs separate sugars into four distinct groups that correlate with sugar nutritional value and palatability. We also identified a third GRN that responded to stimulation with relatively high concentrations of fructose, sucrose, and maltose. Sugars that were nonmetabolizable or toxic suppressed the responses of bursting GRNs to sucrose. These abilities to encode information about sugar value are a refinement to the bumblebee’s sense of sweet taste that could be an adaptation that enables precise calculations of the nature and nutritional value of floral nectar. Up to three gustatory receptor neurons (GRNs) per galeal sensillum respond to sugars Bumblebee GRNs produce a bursting pattern in response to sugars of high nutritional value Response patterns of GRNs can be grouped by sugar nutritional value Nonmetabolizable and toxic sugars suppress the responses of bursting GRNs to sucrose
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Affiliation(s)
| | - Sébastien C Kessler
- Institute of Neuroscience, Newcastle University, Newcastle-upon-Tyne NE2 4HH, UK
| | - Jennifer Scott
- Department of Zoology, University of Oxford, Oxford OX1 3SZ, UK
| | - Alexander Simpson
- Institute of Neuroscience, Newcastle University, Newcastle-upon-Tyne NE2 4HH, UK
| | - Jennifer Bu
- School of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | | | - Adam Mahdi
- Oxford Internet Institute, University of Oxford, Oxford OX1 3JS, UK
| | - Ashwin Miriyala
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford OX1 3SR, UK
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Kohatsu S, Tanabe N, Yamamoto D, Isono K. Which Sugar to Take and How Much to Take? Two Distinct Decisions Mediated by Separate Sensory Channels. Front Mol Neurosci 2022; 15:895395. [PMID: 35726300 PMCID: PMC9206540 DOI: 10.3389/fnmol.2022.895395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 05/09/2022] [Indexed: 11/13/2022] Open
Abstract
In Drosophila melanogaster, gustatory receptor neurons (GRNs) for sugar taste coexpress various combinations of gustatory receptor (Gr) genes and are found in multiple sites in the body. To determine whether diverse sugar GRNs expressing different combinations of Grs have distinct behavioral roles, we examined the effects on feeding behavior of genetic manipulations which promote or suppress functions of GRNs that express either or both of the sugar receptor genesGr5a (Gr5a+ GRNs) and Gr61a (Gr61a+ GRNs). Cell-population-specific overexpression of the wild-type form of Gr5a (Gr5a+) in the Gr5a mutant background revealed that Gr61a+ GRNs localized on the legs and internal mouthpart critically contribute to food choice but not to meal size decisions, while Gr5a+ GRNs, which are broadly expressed in many sugar-responsive cells across the body with an enrichment in the labella, are involved in both food choice and meal size decisions. The legs harbor two classes of Gr61a expressing GRNs, one with Gr5a expression (Gr5a+/Gr61a+ GRNs) and the other without Gr5aexpression (Gr5a−/Gr61a+ GRNs). We found that blocking the Gr5a+ class in the entire body reduced the preference for trehalose and blocking the Gr5a- class reduced the preference for fructose. These two subsets of GRNsare also different in their central projections: axons of tarsal Gr5a+/Gr61a+ GRNs terminate exclusively in the ventral nerve cord, while some axons of tarsal Gr5a−/Gr61a+ GRNs ascend through the cervical connectives to terminate in the subesophageal ganglion. We propose that tarsal Gr5a+/Gr61a+ GRNs and Gr5a−/Gr61a+ GRNs represent functionally distinct sensory pathways that function differently in food preference and meal-size decisions.
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Affiliation(s)
- Soh Kohatsu
- Neuro-ICT Laboratory, Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Japan
- *Correspondence: Soh Kohatsu Kunio Isono
| | - Noriko Tanabe
- Fukuoka Junior College for Kindergarten Teachers, Fukuoka, Japan
| | - Daisuke Yamamoto
- Neuro-ICT Laboratory, Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Japan
| | - Kunio Isono
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
- *Correspondence: Soh Kohatsu Kunio Isono
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Engert S, Sterne GR, Bock DD, Scott K. Drosophila gustatory projections are segregated by taste modality and connectivity. eLife 2022; 11:78110. [PMID: 35611959 PMCID: PMC9170244 DOI: 10.7554/elife.78110] [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: 02/23/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
Gustatory sensory neurons detect caloric and harmful compounds in potential food and convey this information to the brain to inform feeding decisions. To examine the signals that gustatory neurons transmit and receive, we reconstructed gustatory axons and their synaptic sites in the adult Drosophila melanogaster brain, utilizing a whole-brain electron microscopy volume. We reconstructed 87 gustatory projections from the proboscis labellum in the right hemisphere and 57 from the left, representing the majority of labellar gustatory axons. Gustatory neurons contain a nearly equal number of interspersed pre-and post-synaptic sites, with extensive synaptic connectivity among gustatory axons. Morphology- and connectivity-based clustering revealed six distinct groups, likely representing neurons recognizing different taste modalities. The vast majority of synaptic connections are between neurons of the same group. This study resolves the anatomy of labellar gustatory projections, reveals that gustatory projections are segregated based on taste modality, and uncovers synaptic connections that may alter the transmission of gustatory signals.
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Affiliation(s)
- Stefanie Engert
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Gabriella R Sterne
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, United States
| | - Davi D Bock
- Department of Neurological Sciences, University of Vermont, Burlington, United States
| | - Kristin Scott
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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Aryal B, Lee Y. Histamine avoidance through three gustatory receptors in Drosophila melanogaster. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 144:103760. [PMID: 35346814 DOI: 10.1016/j.ibmb.2022.103760] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/15/2022] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Histamine is a fermented food product that exerts adverse health effects on animals when consumed in high amounts. This biogenic amine is fermented by microorganisms from histidine through the activity of histidine decarboxylase. Drosophila melanogaster can discriminate histidine and histamine using GR22e and IR76b in bitter-sensing gustatory receptor neurons (GRNs). In this study, RNA interference screens were conducted to examine 28 uncharacterized gustatory receptor genes using electrophysiology and behavioral experiments, including the binary food choice and proboscis extension response assays. GR9a and GR98a were first identified as specific histamine receptors by evaluating newly generated null mutants and recovery experiments by expressing their wild-type cDNA in the bitter-sensing GRNs. We further determined that histamine sensation was mainly mediated by the labellum but not by the legs, as demonstrated by the proboscis extension response assay. Our findings indicated that toxic histamine directly activates bitter-sensing GRNs in S-type sensilla, and this response is mediated by the GR9a, GR22e, and GR98a gustatory receptors.
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Affiliation(s)
- Binod Aryal
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea.
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Aryal B, Dhakal S, Shrestha B, Lee Y. Molecular and neuronal mechanisms for amino acid taste perception in the Drosophila labellum. Curr Biol 2022; 32:1376-1386.e4. [PMID: 35176225 DOI: 10.1016/j.cub.2022.01.060] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/19/2021] [Accepted: 01/21/2022] [Indexed: 12/22/2022]
Abstract
Amino acids are essential nutrients that act as building blocks for protein synthesis. Recent studies in Drosophila have demonstrated that glycine, phenylalanine, and threonine elicit attraction, whereas tryptophan elicits aversion at ecologically relevant concentrations. Here, we demonstrated that eight amino acids, including arginine, glycine, alanine, serine, phenylalanine, threonine, cysteine, and proline, differentially stimulate feeding behavior by activating sweet-sensing gustatory receptor neurons (GRNs) in L-type and S-type sensilla. In turn, this process is mediated by three GRs (GR5a, GR61a, and GR64f), as well as two broadly required ionotropic receptors (IRs), IR25a and IR76b. However, GR5a, GR61a, and GR64f are only required for sensing amino acids in the sweet-sensing GRNs of L-type sensilla. This suggests that amino acid sensing in different type sensilla occurs through dual mechanisms. Furthermore, our findings indicated that ecologically relevant high concentrations of arginine, lysine, proline, valine, tryptophan, isoleucine, and leucine elicit aversive responses via bitter-sensing GRNs, which are mediated by three IRs (IR25a, IR51b, and IR76b). More importantly, our results demonstrate that arginine, lysine, and proline induce biphasic responses in a concentration-dependent manner. Therefore, amino acid detection in Drosophila occurs through two classes of receptors that activate two sets of sensory neurons in physiologically distinct pathways, which ultimately mediates attraction or aversion behaviors.
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Affiliation(s)
- Binod Aryal
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea
| | - Subash Dhakal
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea
| | - Bhanu Shrestha
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea; Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul 02707, Republic of Korea.
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Shrestha B, Nhuchhen Pradhan R, Nath DK, Lee Y. Cellular and molecular basis of IR3535 perception in Drosophila. PEST MANAGEMENT SCIENCE 2022; 78:793-802. [PMID: 34708523 DOI: 10.1002/ps.6693] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/24/2021] [Accepted: 10/28/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND IR3535 is among the most widely used synthetic insect repellents, particularly for the mitigation of mosquito-borne diseases such as malaria, yellow fever, dengue and Zika, as well as to control flies, ticks, fleas, lice and mites. These insects are well-known vectors of deadly diseases that affect humans, livestock and crops. Moreover, global warming could increase the populations of these vectors. RESULTS Here, we performed IR3535 dose-response analyses on Drosophila melanogaster, a well-known insect model organism, using electrophysiology and binary food choice assays. Our findings indicated that bitter-sensing gustatory receptor neurons (GRNs) are indispensable to detect IR3535. Further, potential candidate gustatory receptors were screened, among which GR47a was identified as a key molecular sensor. IR3535 concentrations in the range 0.1-0.4% affected larval development and mortality. In addition, N,N-diethyl-m-toluamide (DEET, another commonly used insecticide) was found to exert synergistic effects when co-administered with IR3535. CONCLUSION Our findings confirmed that IR3535 directly activates bitter-sensing GRNs, which are mediated by GR47a. This relatively safe and highly potent insecticide can be largely used in combination with DEET to increase its efficiency to protect livestock and crops. Collectively, our findings suggest that the molecular sensors elucidated herein could be used as targets for the development of alternative insecticides. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Bhanu Shrestha
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
| | - Roshani Nhuchhen Pradhan
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
| | - Dharmendra Kumar Nath
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul, Republic of Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul, Republic of Korea
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A functional division of Drosophila sweet taste neurons that is value-based and task-specific. Proc Natl Acad Sci U S A 2022; 119:2110158119. [PMID: 35031566 PMCID: PMC8784143 DOI: 10.1073/pnas.2110158119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2021] [Indexed: 11/18/2022] Open
Abstract
Sucrose is an attractive feeding substance and a positive reinforcer for Drosophila But Drosophila females have been shown to robustly reject a sucrose-containing option for egg-laying when given a choice between a plain and a sucrose-containing option in specific contexts. How the sweet taste system of Drosophila promotes context-dependent devaluation of an egg-laying option that contains sucrose, an otherwise highly appetitive tastant, is unknown. Here, we report that devaluation of sweetness/sucrose for egg-laying is executed by a sensory pathway recruited specifically by the sweet neurons on the legs of Drosophila First, silencing just the leg sweet neurons caused acceptance of the sucrose option in a sucrose versus plain decision, whereas expressing the channelrhodopsin CsChrimson in them caused rejection of a plain option that was "baited" with light over another that was not. Analogous bidirectional manipulations of other sweet neurons did not produce these effects. Second, circuit tracing revealed that the leg sweet neurons receive different presynaptic neuromodulations compared to some other sweet neurons and were the only ones with postsynaptic partners that projected prominently to the superior lateral protocerebrum (SLP) in the brain. Third, silencing one specific SLP-projecting postsynaptic partner of the leg sweet neurons reduced sucrose rejection, whereas expressing CsChrimson in it promoted rejection of a light-baited option during egg-laying. These results uncover that the Drosophila sweet taste system exhibits a functional division that is value-based and task-specific, challenging the conventional view that the system adheres to a simple labeled-line coding scheme.
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31
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Yao Z, Scott K. Serotonergic neurons translate taste detection into internal nutrient regulation. Neuron 2022; 110:1036-1050.e7. [PMID: 35051377 DOI: 10.1016/j.neuron.2021.12.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/26/2021] [Accepted: 12/16/2021] [Indexed: 12/20/2022]
Abstract
The nervous and endocrine systems coordinately monitor and regulate nutrient availability to maintain energy homeostasis. Sensory detection of food regulates internal nutrient availability in a manner that anticipates food intake, but sensory pathways that promote anticipatory physiological changes remain unclear. Here, we identify serotonergic (5-HT) neurons as critical mediators that transform gustatory detection by sensory neurons into the activation of insulin-producing cells and enteric neurons in Drosophila. One class of 5-HT neurons responds to gustatory detection of sugars, excites insulin-producing cells, and limits consumption, suggesting that they anticipate increased nutrient levels and prevent overconsumption. A second class of 5-HT neurons responds to gustatory detection of bitter compounds and activates enteric neurons to promote gastric motility, likely to stimulate digestion and increase circulating nutrients upon food rejection. These studies demonstrate that 5-HT neurons relay acute gustatory detection to divergent pathways for longer-term stabilization of circulating nutrients.
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Affiliation(s)
- Zepeng Yao
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Kristin Scott
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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Shrestha B, Lee Y. Mechanisms of Carboxylic Acid Attraction in Drosophila melanogaster. Mol Cells 2021; 44:900-910. [PMID: 34711686 PMCID: PMC8718364 DOI: 10.14348/molcells.2021.0205] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/07/2021] [Accepted: 10/15/2021] [Indexed: 11/27/2022] Open
Abstract
Sour is one of the fundamental taste modalities that enable taste perception in animals. Chemoreceptors embedded in taste organs are pivotal to discriminate between different chemicals to ensure survival. Animals generally prefer slightly acidic food and avoid highly acidic alternatives. We recently proposed that all acids are aversive at high concentrations, a response that is mediated by low pH as well as specific anions in Drosophila melanogaster. Particularly, some carboxylic acids such as glycolic acid, citric acid, and lactic acid are highly attractive to Drosophila compared with acetic acid. The present study determined that attractive carboxylic acids were mediated by broadly expressed Ir25a and Ir76b, as demonstrated by a candidate mutant library screen. The mutant deficits were completely recovered via wild-type cDNA expression in sweet-sensing gustatory receptor neurons. Furthermore, sweet gustatory receptors such as Gr5a, Gr61a, and Gr64a-f modulate attractive responses. These genetic defects were confirmed using binary food choice assays as well as electrophysiology in the labellum. Taken together, our findings demonstrate that at least two different kinds of receptors are required to discriminate attractive carboxylic acids from other acids.
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Affiliation(s)
- Bhanu Shrestha
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul 02707, Korea
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Excessive energy expenditure due to acute physical restraint disrupts Drosophila motivational feeding response. Sci Rep 2021; 11:24208. [PMID: 34921197 PMCID: PMC8683507 DOI: 10.1038/s41598-021-03575-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 12/03/2021] [Indexed: 11/22/2022] Open
Abstract
To study the behavior of Drosophila, it is often necessary to restrain and mount individual flies. This requires removal from food, additional handling, anesthesia, and physical restraint. We find a strong positive correlation between the length of time flies are mounted and their subsequent reflexive feeding response, where one hour of mounting is the approximate motivational equivalent to ten hours of fasting. In an attempt to explain this correlation, we rule out anesthesia side-effects, handling, additional fasting, and desiccation. We use respirometric and metabolic techniques coupled with behavioral video scoring to assess energy expenditure in mounted and free flies. We isolate a specific behavior capable of exerting large amounts of energy in mounted flies and identify it as an attempt to escape from restraint. We present a model where physical restraint leads to elevated activity and subsequent faster nutrient storage depletion among mounted flies. This ultimately further accelerates starvation and thus increases reflexive feeding response. In addition, we show that the consequences of the physical restraint profoundly alter aerobic activity, energy depletion, taste, and feeding behavior, and suggest that careful consideration is given to the time-sensitive nature of these highly significant effects when conducting behavioral, physiological or imaging experiments that require immobilization.
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Maier GL, Komarov N, Meyenhofer F, Kwon JY, Sprecher SG. Taste sensing and sugar detection mechanisms in Drosophila larval primary taste center. eLife 2021; 10:67844. [PMID: 34859782 PMCID: PMC8709573 DOI: 10.7554/elife.67844] [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: 02/24/2021] [Accepted: 11/23/2021] [Indexed: 11/25/2022] Open
Abstract
Despite the small number of gustatory sense neurons, Drosophila larvae are able to sense a wide range of chemicals. Although evidence for taste multimodality has been provided in single neurons, an overview of gustatory responses at the periphery is missing and hereby we explore whole-organ calcium imaging of the external taste center. We find that neurons can be activated by different combinations of taste modalities, including opposite hedonic valence and identify distinct temporal dynamics of response. Although sweet sensing has not been fully characterized so far in the external larval gustatory organ, we recorded responses elicited by sugar. Previous findings established that larval sugar sensing relies on the Gr43a pharyngeal receptor, but the question remains if external neurons contribute to this taste. Here, we postulate that external and internal gustation use distinct and complementary mechanisms in sugar sensing and we identify external sucrose sensing neurons.
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Affiliation(s)
- G Larisa Maier
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Nikita Komarov
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Felix Meyenhofer
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Republic of Korea
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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Dhakal S, Sang J, Aryal B, Lee Y. Ionotropic receptors mediate nitrogenous waste avoidance in Drosophila melanogaster. Commun Biol 2021; 4:1281. [PMID: 34773080 PMCID: PMC8589963 DOI: 10.1038/s42003-021-02799-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 10/19/2021] [Indexed: 01/03/2023] Open
Abstract
Ammonia and its amine-containing derivatives are widely found in natural decomposition byproducts. Here, we conducted biased chemoreceptor screening to investigate the mechanisms by which different concentrations of ammonium salt, urea, and putrescine in rotten fruits affect feeding and oviposition behavior. We identified three ionotropic receptors, including the two broadly required IR25a and IR76b receptors, as well as the narrowly tuned IR51b receptor. These three IRs were fundamental in eliciting avoidance against nitrogenous waste products, which is mediated by bitter-sensing gustatory receptor neurons (GRNs). The aversion of nitrogenous wastes was evaluated by the cellular requirement by expressing Kir2.1 and behavioral recoveries of the mutants in bitter-sensing GRNs. Furthermore, by conducting electrophysiology assays, we confirmed that ammonia compounds are aversive in taste as they directly activated bitter-sensing GRNs. Therefore, our findings provide insights into the ecological roles of IRs as a means to detect and avoid toxic nitrogenous waste products in nature.
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Affiliation(s)
- Subash Dhakal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Jiun Sang
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Binod Aryal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea.
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul, 02707, Republic of Korea.
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36
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Mitra S, Pinch M, Kandel Y, Li Y, Rodriguez SD, Hansen IA. Olfaction-Related Gene Expression in the Antennae of Female Mosquitoes From Common Aedes aegypti Laboratory Strains. Front Physiol 2021; 12:668236. [PMID: 34497531 PMCID: PMC8419471 DOI: 10.3389/fphys.2021.668236] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 08/02/2021] [Indexed: 11/17/2022] Open
Abstract
Adult female mosquitoes rely on olfactory cues like carbon dioxide and other small molecules to find vertebrate hosts to acquire blood. The molecular physiology of the mosquito olfactory system is critical for their host preferences. Many laboratory strains of the yellow fever mosquito Aedes aegypti have been established since the late 19th century. These strains have been used for most molecular studies in this species. Some earlier comparative studies have identified significant physiological differences between different laboratory strains. In this study, we used a Y-tube olfactometer to determine the attraction of females of seven different strains of Ae. aegypti to a human host: UGAL, Rockefeller, Liverpool, Costa Rica, Puerto Rico, and two odorant receptor co-receptor (Orco) mutants Orco2 and Orco16. We performed RNA-seq using antennae of Rockefeller, Liverpool, Costa Rica, and Puerto Rico females. Our results showed that female Aedes aegypti from the Puerto Rico strain had significantly reduced attraction rates toward human hosts compared to all other strains. RNA-seq analyses of the antenna transcriptomes of Rockefeller, Liverpool, Costa Rica, and Puerto Rico strains revealed distinct differences in gene expression between the four strains, but conservation in gene expression patterns of known human-sensing genes. However, we identified several olfaction-related genes that significantly vary between strains, including receptors with significantly different expression in mosquitoes from the Puerto Rico strain and the other strains.
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Affiliation(s)
- Soumi Mitra
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Matthew Pinch
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Yashoda Kandel
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Yiyi Li
- Department of Computer Science, New Mexico State University, Las Cruces, NM, United States
| | - Stacy D Rodriguez
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
| | - Immo A Hansen
- Department of Biology, New Mexico State University, Las Cruces, NM, United States
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Sterne GR, Otsuna H, Dickson BJ, Scott K. Classification and genetic targeting of cell types in the primary taste and premotor center of the adult Drosophila brain. eLife 2021; 10:e71679. [PMID: 34473057 PMCID: PMC8445619 DOI: 10.7554/elife.71679] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 09/01/2021] [Indexed: 12/29/2022] Open
Abstract
Neural circuits carry out complex computations that allow animals to evaluate food, select mates, move toward attractive stimuli, and move away from threats. In insects, the subesophageal zone (SEZ) is a brain region that receives gustatory, pheromonal, and mechanosensory inputs and contributes to the control of diverse behaviors, including feeding, grooming, and locomotion. Despite its importance in sensorimotor transformations, the study of SEZ circuits has been hindered by limited knowledge of the underlying diversity of SEZ neurons. Here, we generate a collection of split-GAL4 lines that provides precise genetic targeting of 138 different SEZ cell types in adult Drosophila melanogaster, comprising approximately one third of all SEZ neurons. We characterize the single-cell anatomy of these neurons and find that they cluster by morphology into six supergroups that organize the SEZ into discrete anatomical domains. We find that the majority of local SEZ interneurons are not classically polarized, suggesting rich local processing, whereas SEZ projection neurons tend to be classically polarized, conveying information to a limited number of higher brain regions. This study provides insight into the anatomical organization of the SEZ and generates resources that will facilitate further study of SEZ neurons and their contributions to sensory processing and behavior.
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Affiliation(s)
- Gabriella R Sterne
- University of California BerkeleyBerkeleyUnited States
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Hideo Otsuna
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Barry J Dickson
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
- Queensland Brain Institute, University of QueenslandQueenslandAustralia
| | - Kristin Scott
- University of California BerkeleyBerkeleyUnited States
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38
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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: 46] [Impact Index Per Article: 15.3] [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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39
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Aryal B, Lee Y. Histamine gustatory aversion in Drosophila melanogaster. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2021; 134:103586. [PMID: 33992752 DOI: 10.1016/j.ibmb.2021.103586] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/30/2021] [Accepted: 05/01/2021] [Indexed: 06/12/2023]
Abstract
Many foods and drinks contain histamine; however, the mechanisms that drive histamine taste perception have not yet been investigated. Here, we use a simple model organism, Drosophila melanogaster, to dissect the molecular sensors required to taste histamine. We first investigated histidine and histamine taste perception by performing a binary food choice assay and electrophysiology to identify essential sensilla for histamine sensing in the labellum. Histamine was found to activate S-type sensilla, which harbor bitter-sensing gustatory receptor neurons. Moreover, unbiased genetic screening for chemoreceptors revealed that a gustatory receptor, GR22e and an ionotropic receptor, IR76b are required for histamine sensing. Ectopic expression of GR22e was sufficient to induce a response in I-type sensilla, which normally do not respond to histamine. Taken together, our findings provide new insights into the mechanisms by which insects discriminate between the toxic histamine and beneficial histidine via their taste receptors.
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Affiliation(s)
- Binod Aryal
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea; Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul, 02707, Republic of Korea.
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40
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Stanley M, Ghosh B, Weiss ZF, Christiaanse J, Gordon MD. Mechanisms of lactic acid gustatory attraction in Drosophila. Curr Biol 2021; 31:3525-3537.e6. [PMID: 34197729 DOI: 10.1016/j.cub.2021.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/30/2021] [Accepted: 06/02/2021] [Indexed: 01/05/2023]
Abstract
Sour has been studied almost exclusively as an aversive taste modality. Yet recent work in Drosophila demonstrates that specific carboxylic acids are attractive at ecologically relevant concentrations. Here, we demonstrate that lactic acid is an appetitive and energetic tastant, which stimulates feeding through activation of sweet gustatory receptor neurons (GRNs). This activation displays distinct, mechanistically separable stimulus onset and removal phases. Ionotropic receptor 25a (IR25a) primarily mediates the onset response, which shows specificity for the lactate anion and drives feeding initiation through proboscis extension. Conversely, sweet gustatory receptors (Gr64a-f) mediate a non-specific removal response to low pH that primarily impacts ingestion. While mutations in either receptor family have marginal impacts on feeding, lactic acid attraction is completely abolished in combined mutants. Thus, specific components of lactic acid are detected through two classes of receptors to activate a single set of sensory neurons in physiologically distinct ways, ultimately leading to robust behavioral attraction.
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Affiliation(s)
- Molly Stanley
- Department of Zoology and Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Britya Ghosh
- Department of Zoology and Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada; Graduate Program in Cell and Developmental Biology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Zachary F Weiss
- Department of Zoology and Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Jaime Christiaanse
- Department of Zoology and Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Michael D Gordon
- Department of Zoology and Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
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41
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Lau CKS, Jelen M, Gordon MD. A closed-loop optogenetic screen for neurons controlling feeding in Drosophila. G3-GENES GENOMES GENETICS 2021; 11:6170659. [PMID: 33714999 PMCID: PMC8104954 DOI: 10.1093/g3journal/jkab073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 03/03/2021] [Indexed: 11/14/2022]
Abstract
Feeding is an essential part of animal life that is greatly impacted by the sense of taste. Although the characterization of taste-detection at the periphery has been extensive, higher order taste and feeding circuits are still being elucidated. Here, we use an automated closed-loop optogenetic activation screen to detect novel taste and feeding neurons in Drosophila melanogaster. Out of 122 Janelia FlyLight Project GAL4 lines preselected based on expression pattern, we identify six lines that acutely promote feeding and 35 lines that inhibit it. As proof of principle, we follow up on R70C07-GAL4, which labels neurons that strongly inhibit feeding. Using split-GAL4 lines to isolate subsets of the R70C07-GAL4 population, we find both appetitive and aversive neurons. Furthermore, we show that R70C07-GAL4 labels putative second-order taste interneurons that contact both sweet and bitter sensory neurons. These results serve as a resource for further functional dissection of fly feeding circuits.
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Affiliation(s)
- Celia K S Lau
- Department of Zoology and Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Meghan Jelen
- Department of Zoology and Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Michael D Gordon
- Department of Zoology and Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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42
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Brown EB, Shah KD, Palermo J, Dey M, Dahanukar A, Keene AC. Ir56d-dependent fatty acid responses in Drosophila uncover taste discrimination between different classes of fatty acids. eLife 2021; 10:67878. [PMID: 33949306 PMCID: PMC8169106 DOI: 10.7554/elife.67878] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/04/2021] [Indexed: 11/24/2022] Open
Abstract
Chemosensory systems are critical for evaluating the caloric value and potential toxicity of food. While animals can discriminate between thousands of odors, much less is known about the discriminative capabilities of taste systems. Fats and sugars represent calorically potent and attractive food sources that contribute to hedonic feeding. Despite the differences in nutritional value between fats and sugars, the ability of the taste system to discriminate between different rewarding tastants is thought to be limited. In Drosophila, taste neurons expressing the ionotropic receptor 56d (IR56d) are required for reflexive behavioral responses to the medium-chain fatty acid, hexanoic acid. Here, we tested whether flies can discriminate between different classes of fatty acids using an aversive memory assay. Our results indicate that flies are able to discriminate medium-chain fatty acids from both short- and long-chain fatty acids, but not from other medium-chain fatty acids. While IR56d neurons are broadly responsive to short-, medium-, and long-chain fatty acids, genetic deletion of IR56d selectively disrupts response to medium-chain fatty acids. Further, IR56d+ GR64f+ neurons are necessary for proboscis extension response (PER) to medium-chain fatty acids, but both IR56d and GR64f neurons are dispensable for PER to short- and long-chain fatty acids, indicating the involvement of one or more other classes of neurons. Together, these findings reveal that IR56d is selectively required for medium-chain fatty acid taste, and discrimination of fatty acids occurs through differential receptor activation in shared populations of neurons. Our study uncovers a capacity for the taste system to encode tastant identity within a taste category.
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Affiliation(s)
- Elizabeth B Brown
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States
| | - Kreesha D Shah
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States.,Wilkes Honors College, Florida Atlantic University, Jupiter, United States
| | - Justin Palermo
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States
| | - Manali Dey
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, United States
| | - Anupama Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, United States.,Department of Molecular, Cell & Systems Biology, University of California, Riverside, Riverside, United States
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, United States
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43
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Bestea L, Réjaud A, Sandoz JC, Carcaud J, Giurfa M, de Brito Sanchez MG. Peripheral taste detection in honey bees: What do taste receptors respond to? Eur J Neurosci 2021; 54:4417-4444. [PMID: 33934411 DOI: 10.1111/ejn.15265] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 11/30/2022]
Abstract
Understanding the neural principles governing taste perception in species that bear economic importance or serve as research models for other sensory modalities constitutes a strategic goal. Such is the case of the honey bee (Apis mellifera), which is environmentally and socioeconomically important, given its crucial role as pollinator agent in agricultural landscapes and which has served as a traditional model for visual and olfactory neurosciences and for research on communication, navigation, and learning and memory. Here we review the current knowledge on honey bee gustatory receptors to provide an integrative view of peripheral taste detection in this insect, highlighting specificities and commonalities with other insect species. We describe behavioral and electrophysiological responses to several tastant categories and relate these responses, whenever possible, to known molecular receptor mechanisms. Overall, we adopted an evolutionary and comparative perspective to understand the neural principles of honey bee taste and define key questions that should be answered in future gustatory research centered on this insect.
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Affiliation(s)
- Louise Bestea
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS (UMR 5169), University of Toulouse, Toulouse, France
| | - Alexandre Réjaud
- Laboratoire Evolution et Diversité Biologique, CNRS, IRD (UMR 5174), University of Toulouse, Toulouse, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, CNRS, IRD (UMR 9191, University Paris Saclay, Gif-sur-Yvette, France
| | - Julie Carcaud
- Evolution, Genomes, Behavior and Ecology, CNRS, IRD (UMR 9191, University Paris Saclay, Gif-sur-Yvette, France
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS (UMR 5169), University of Toulouse, Toulouse, France.,College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou, China.,Institut Universitaire de France (IUF), Paris, France
| | - Maria Gabriela de Brito Sanchez
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS (UMR 5169), University of Toulouse, Toulouse, France
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44
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Olafson PU, Aksoy S, Attardo GM, Buckmeier G, Chen X, Coates CJ, Davis M, Dykema J, Emrich SJ, Friedrich M, Holmes CJ, Ioannidis P, Jansen EN, Jennings EC, Lawson D, Martinson EO, Maslen GL, Meisel RP, Murphy TD, Nayduch D, Nelson DR, Oyen KJ, Raszick TJ, Ribeiro JMC, Robertson HM, Rosendale AJ, Sackton TB, Saelao P, Swiger SL, Sze SH, Tarone AM, Taylor DB, Warren WC, Waterhouse RM, Weirauch MT, Werren JH, Wilson RK, Zdobnov EM, Benoit JB. The genome of the stable fly, Stomoxys calcitrans, reveals potential mechanisms underlying reproduction, host interactions, and novel targets for pest control. BMC Biol 2021; 19:41. [PMID: 33750380 PMCID: PMC7944917 DOI: 10.1186/s12915-021-00975-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 02/03/2021] [Indexed: 01/01/2023] Open
Abstract
Background The stable fly, Stomoxys calcitrans, is a major blood-feeding pest of livestock that has near worldwide distribution, causing an annual cost of over $2 billion for control and product loss in the USA alone. Control of these flies has been limited to increased sanitary management practices and insecticide application for suppressing larval stages. Few genetic and molecular resources are available to help in developing novel methods for controlling stable flies. Results This study examines stable fly biology by utilizing a combination of high-quality genome sequencing and RNA-Seq analyses targeting multiple developmental stages and tissues. In conjunction, 1600 genes were manually curated to characterize genetic features related to stable fly reproduction, vector host interactions, host-microbe dynamics, and putative targets for control. Most notable was characterization of genes associated with reproduction and identification of expanded gene families with functional associations to vision, chemosensation, immunity, and metabolic detoxification pathways. Conclusions The combined sequencing, assembly, and curation of the male stable fly genome followed by RNA-Seq and downstream analyses provide insights necessary to understand the biology of this important pest. These resources and new data will provide the groundwork for expanding the tools available to control stable fly infestations. The close relationship of Stomoxys to other blood-feeding (horn flies and Glossina) and non-blood-feeding flies (house flies, medflies, Drosophila) will facilitate understanding of the evolutionary processes associated with development of blood feeding among the Cyclorrhapha. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-00975-9.
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Affiliation(s)
- Pia U Olafson
- Livestock Arthropod Pests Research Unit, USDA-ARS, Kerrville, TX, USA.
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Geoffrey M Attardo
- Department of Entomology and Nematology, University of California - Davis, Davis, CA, USA
| | - Greta Buckmeier
- Livestock Arthropod Pests Research Unit, USDA-ARS, Kerrville, TX, USA
| | - Xiaoting Chen
- The Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Craig J Coates
- Department of Entomology, Texas A & M University, College Station, TX, USA
| | - Megan Davis
- Livestock Arthropod Pests Research Unit, USDA-ARS, Kerrville, TX, USA
| | - Justin Dykema
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA
| | - Scott J Emrich
- Department of Electrical Engineering & Computer Science, University of Tennessee, Knoxville, TN, USA
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, Detroit, MI, USA
| | - Christopher J Holmes
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Panagiotis Ioannidis
- Department of Genetic Medicine and Development, University of Geneva Medical School and Swiss Institute of Bioinformatics, 1211, Geneva, Switzerland
| | - Evan N Jansen
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Emily C Jennings
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Daniel Lawson
- The European Molecular Biology Laboratory, The European Bioinformatics Institute, The Wellcome Genome Campus, Hinxton, CB10 1SD, UK
| | | | - Gareth L Maslen
- The European Molecular Biology Laboratory, The European Bioinformatics Institute, The Wellcome Genome Campus, Hinxton, CB10 1SD, UK
| | - Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Terence D Murphy
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Dana Nayduch
- Arthropod-borne Animal Diseases Research Unit, USDA-ARS, Manhattan, KS, USA
| | - David R Nelson
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Kennan J Oyen
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Tyler J Raszick
- Department of Entomology, Texas A & M University, College Station, TX, USA
| | - José M C Ribeiro
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD, USA
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | | | - Timothy B Sackton
- Informatics Group, Faculty of Arts and Sciences, Harvard University, Cambridge, MA, USA
| | - Perot Saelao
- Livestock Arthropod Pests Research Unit, USDA-ARS, Kerrville, TX, USA
| | - Sonja L Swiger
- Department of Entomology, Texas A&M AgriLife Research and Extension Center, Stephenville, TX, USA
| | - Sing-Hoi Sze
- Department of Computer Science & Engineering, Department of Biochemistry & Biophysics, Texas A & M University, College Station, TX, USA
| | - Aaron M Tarone
- Department of Entomology, Texas A & M University, College Station, TX, USA
| | - David B Taylor
- Agroecosystem Management Research Unit, USDA-ARS, Lincoln, NE, USA
| | - Wesley C Warren
- University of Missouri, Bond Life Sciences Center, Columbia, MO, USA
| | - Robert M Waterhouse
- Department of Ecology and Evolution, University of Lausanne, and Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology, Divisions of Biomedical Informatics and Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - John H Werren
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Richard K Wilson
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA.,College of Medicine, Ohio State University, Columbus, OH, USA
| | - Evgeny M Zdobnov
- Department of Genetic Medicine and Development, University of Geneva Medical School and Swiss Institute of Bioinformatics, 1211, Geneva, Switzerland
| | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA.
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45
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Yang K, Gong XL, Li GC, Huang LQ, Ning C, Wang CZ. A gustatory receptor tuned to the steroid plant hormone brassinolide in Plutella xylostella (Lepidoptera: Plutellidae). eLife 2020; 9:64114. [PMID: 33305735 PMCID: PMC7806260 DOI: 10.7554/elife.64114] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/10/2020] [Indexed: 01/18/2023] Open
Abstract
Feeding and oviposition deterrents help phytophagous insects to identify host plants. The taste organs of phytophagous insects contain bitter gustatory receptors (GRs). To explore their function, the GRs in Plutella xylostella were analyzed. Through RNA sequencing and qPCR, we detected abundant PxylGr34 transcripts in the larval head and adult antennae. Functional analyses using the Xenopus oocyte expression system and 24 diverse phytochemicals showed that PxylGr34 is tuned to the canonical plant hormones brassinolide (BL) and 24-epibrassinolide (EBL). Electrophysiological analyses revealed that the medial sensilla styloconica of 4th instar larvae are responsive to BL and EBL. Dual-choice bioassays demonstrated that BL inhibits larval feeding and female oviposition. Knock-down of PxylGr34 by RNAi attenuates the taste responses to BL, and abolishes BL-induced feeding inhibition. These results increase our understanding of how herbivorous insects detect compounds that deter feeding and oviposition, and may be useful for designing plant hormone-based pest management strategies. Plant-eating insects use their sense of taste to decide where to feed and where to lay their eggs. They do this using taste sensors called gustatory receptors which reside in the antennae and legs of adults, and in the mouthparts of larvae. Some of these sensors detect sugars which signal to the insect that the plant is a nutritious source of food. While others detect bitter compounds, such as poisons released by plants in self-defense. One of the most widespread plant-eating insects is the diamondback moth, which feeds and lays its eggs on cruciferous vegetable crops, like cabbage, oilseed rape and broccoli. Before laying its eggs, female diamondback moths pat the vegetable’s leaves with their antennae, tasting for the presence of chemicals. But little was known about the identity of these chemicals. Cabbages produce large amounts of a hormone called brassinolide, which is known to play a role in plant growth. To find out whether diamondback moths can taste this hormone, Yang et al. examined all their known gustatory receptors. This revealed that the adult antennae and larval mouthparts of these moths make high levels of a receptor called PxylGr34. To investigate the role of PxylGr34, Yang et al. genetically modified frog eggs to produce this receptor. Various tests on these receptors, as well as receptors in the mouthparts of diamondback larvae, showed that PxylGr34 is able to sense the hormone brassinolide. To find out how this affects the behavior of the moths, Yang et al. investigated how adults and larvae responded to different levels of the hormone. This revealed that the presence of brassinolide significantly decreased both larval feeding and the amount of eggs laid by adult moths. Farmers already use brassinolide to enhance plant growth and protect crops from stress. These results suggest that the hormone might also help to shield plants from insect damage. However, more research is needed to understand how this hormone acts as a deterrent. Further studies could improve understanding of insect behavior and potentially identify more chemicals that can be used for pest control.
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Affiliation(s)
- Ke Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Xin-Lin Gong
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Guo-Cheng Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Ling-Qiao Huang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Chao Ning
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Chen-Zhu Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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46
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Chen H, Lahey Z, Talamas EJ, Johnson NF. Identification and expression of chemosensory receptor genes in the egg parasitoid Trissolcus basalis. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 37:100758. [PMID: 33202309 DOI: 10.1016/j.cbd.2020.100758] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 11/17/2022]
Abstract
Parasitic wasps largely rely on chemosenses to locate resources. Understanding the evolution of their chemoreceptors can help elucidate the mechanisms underlying host adaptation and speciation. Trissolcus basalis is a biological control agent of the southern green stink bug, a pantropical pest, and is ideal for investigating the evolution of chemoreceptors. We identified 34 gustatory receptors, 170 odorant receptors, one odorant co-receptor, and 23 ionotropic receptors. Comparison with other Hymenoptera revealed species-specific expansions of 21 Grs and 53 Ors. Most of these Or expansions have 9 exons. Gender- and tissue-specific analyses showed that 5 Grs and 54 Ors are expressed only in antennae in both sexes, 66 Ors in female antennae only, and 4 Ors in male antennae alone. The identification and expression profile of chemosensory receptor genes in T. basalis helps in understanding the link between the evolution of chemoreceptors and speciation in parasitic wasps.
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Affiliation(s)
- Huayan Chen
- State Key Laboratory of Biocontrol, School of Life Sciences/School of Ecology, Sun Yat-sen University, Guangzhou 510275, China; Department of Entomology, The Ohio State University, 1315 Kinnear Road, Columbus, OH 43212, USA.
| | - Zachary Lahey
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, 1315 Kinnear Road, Columbus, OH 43212, USA.
| | - Elijah J Talamas
- Department of Entomology, The Ohio State University, 1315 Kinnear Road, Columbus, OH 43212, USA; Florida Department of Agriculture and Consumer Services, The Doyle Conner Building, 1911 SW 34th St, Gainesville, Florida 32608, USA.
| | - Norman F Johnson
- Department of Entomology, The Ohio State University, 1315 Kinnear Road, Columbus, OH 43212, USA; Department of Evolution, Ecology and Organismal Biology, The Ohio State University, 1315 Kinnear Road, Columbus, OH 43212, USA.
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Comparative morphological and transcriptomic analyses reveal chemosensory genes in the poultry red mite, Dermanyssus gallinae. Sci Rep 2020; 10:17923. [PMID: 33087814 PMCID: PMC7578799 DOI: 10.1038/s41598-020-74998-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/08/2020] [Indexed: 11/29/2022] Open
Abstract
Detection of chemical cues via chemosensory receptor proteins are essential for most animals, and underlies critical behaviors, including location and discrimination of food resources, identification of sexual partners and avoidance of predators. The current knowledge of how chemical cues are detected is based primarily on data acquired from studies on insects, while our understanding of the molecular basis for chemoreception in acari, mites in particular, remains limited. The poultry red mite (PRM), Dermanyssus gallinae, is one of the most important blood-feeding ectoparasites of poultry. PRM are active at night which suck the birds' blood during periods of darkness and hide themselves in all kinds of gaps and cracks during the daytime. The diversity in habitat usage, as well as the demonstrated host finding and avoidance behaviors suggest that PRM relies on their sense of smell to orchestrate complex behavioral decisions. Comparative transcriptome analyses revealed the presence of candidate variant ionotropic receptors, odorant binding proteins, niemann-pick proteins type C2 and sensory neuron membrane proteins. Some of these proteins were highly and differentially expressed in the forelegs of PRM. Rhodopsin-like G protein-coupled receptors were also identified, while insect-specific odorant receptors and odorant co-receptors were not detected. Furthermore, using scanning electron microscopy, the tarsomeres of all leg pairs were shown to be equipped with sensilla chaetica with or without tip pores, while wall-pored olfactory sensilla chaetica were restricted to the distal-most tarsomeres of the forelegs. This study is the first to describe the presence of chemosensory genes in any Dermanyssidae family. Our findings make a significant step forward in understanding the chemosensory abilities of D. gallinae.
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Chen YCD, Park SJ, Joseph RM, Ja WW, Dahanukar AA. Combinatorial Pharyngeal Taste Coding for Feeding Avoidance in Adult Drosophila. Cell Rep 2020; 29:961-973.e4. [PMID: 31644916 PMCID: PMC6860367 DOI: 10.1016/j.celrep.2019.09.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 08/18/2019] [Accepted: 09/12/2019] [Indexed: 01/05/2023] Open
Abstract
Taste drives appropriate food preference and intake. In Drosophila, taste neurons are housed in both external and internal organs, but the latter have been relatively underexplored. Here, we report that Poxn mutants with a minimal taste system of pharyngeal neurons can avoid many aversive tastants, including bitter compounds, acid, and salt, suggesting that pharyngeal taste is sufficient for rejecting intake of aversive compounds. Optogenetic activation of selected pharyngeal bitter neurons during feeding events elicits changes in feeding parameters that can suppress intake. Functional dissection experiments indicate that multiple classes of pharyngeal neurons are involved in achieving behavioral avoidance, by virtue of being inhibited or activated by aversive tastants. Tracing second-order pharyngeal circuits reveals two main relay centers for processing pharyngeal taste inputs. Together, our results suggest that the pharynx can control the ingestion of harmful compounds by integrating taste input from different classes of pharyngeal neurons. Chen et al. perform functional and behavioral experiments to study the roles of different subsets of pharyngeal neurons in governing food avoidance in flies. They find evidence that rejection of different categories of aversive compounds is dependent on distinct combinations of pharyngeal taste neurons.
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Affiliation(s)
- Yu-Chieh David Chen
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA
| | - Scarlet Jinhong Park
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA; Skaggs Graduate School, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Ryan Matthew Joseph
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA 92521, USA
| | - William W Ja
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA; Skaggs Graduate School, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Anupama Arun Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA; Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA 92521, USA.
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Ahmed OM, Avila-Herrera A, Tun KM, Serpa PH, Peng J, Parthasarathy S, Knapp JM, Stern DL, Davis GW, Pollard KS, Shah NM. Evolution of Mechanisms that Control Mating in Drosophila Males. Cell Rep 2020; 27:2527-2536.e4. [PMID: 31141679 PMCID: PMC6646047 DOI: 10.1016/j.celrep.2019.04.104] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 02/20/2019] [Accepted: 04/23/2019] [Indexed: 11/17/2022] Open
Abstract
Genetically wired neural mechanisms inhibit mating between species
because even naive animals rarely mate with other species. These mechanisms can
evolve through changes in expression or function of key genes in sensory
pathways or central circuits. Gr32a is a gustatory chemoreceptor that, in
D. melanogaster, is essential to inhibit interspecies
courtship and sense quinine. Similar to D. melanogaster, we
find that D. simulans Gr32a is expressed in foreleg tarsi,
sensorimotor appendages that inhibit interspecies courtship, and it is required
to sense quinine. Nevertheless, Gr32a is not required to inhibit interspecies
mating by D. simulans males. However, and similar to its
function in D. melanogaster, Ppk25, a member of the Pickpocket
family, promotes conspecific courtship in D. simulans.
Together, we have identified distinct evolutionary mechanisms underlying
chemosensory control of taste and courtship in closely related
Drosophila species. Mechanisms that inhibit interspecies mating are critical to reproductive
isolation of species. Ahmed et al. show that Gr32a, a chemoreceptor that
inhibits interspecies courtship by D. melanogaster males, does
not inhibit this behavior in the closely related D. simulans,
indicating rapid evolution of peripheral sensory mechanisms that preclude
interspecies breeding.
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Affiliation(s)
- Osama M Ahmed
- Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94143, USA; Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08540, USA
| | - Aram Avila-Herrera
- Integrative Program in Quantitative Biology, University of California, San Francisco, San Francisco, CA 94158, USA; Computation Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Gladstone Institutes, San Francisco, CA 94158, USA
| | - Khin May Tun
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Paula H Serpa
- Integrative Program in Quantitative Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Justin Peng
- Integrative Program in Quantitative Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Srinivas Parthasarathy
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA; L.E.K. Consulting, 75 State Street, Boston, MA 02109, USA
| | - Jon-Michael Knapp
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Janelia Research Campus, HHMI Ashburn, Ashburn, VA 20147, USA
| | - David L Stern
- Janelia Research Campus, HHMI Ashburn, Ashburn, VA 20147, USA
| | - Graeme W Davis
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Katherine S Pollard
- Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA 94158, USA; Gladstone Institutes, San Francisco, CA 94158, USA
| | - Nirao M Shah
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA; Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA.
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50
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Rimal S, Sang J, Dhakal S, Lee Y. Cucurbitacin B Activates Bitter-Sensing Gustatory Receptor Neurons via Gustatory Receptor 33a in Drosophila melanogaster. Mol Cells 2020; 43:530-538. [PMID: 32451368 PMCID: PMC7332364 DOI: 10.14348/molcells.2020.0019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/08/2020] [Accepted: 04/26/2020] [Indexed: 01/23/2023] Open
Abstract
The Gustatory system enables animals to detect toxic bitter chemicals, which is critical for insects to survive food induced toxicity. Cucurbitacin is widely present in plants such as cucumber and gourds that acts as an anti-herbivore chemical and an insecticide. Cucurbitacin has a harmful effect on insect larvae as well. Although various beneficial effects of cucurbitacin such as alleviating hyperglycemia have also been documented, it is not clear what kinds of molecular sensors are required to detect cucurbitacin in nature. Cucurbitacin B, a major bitter component of bitter melon, was applied to induce action potentials from sensilla of a mouth part of the fly, labellum. Here we identify that only Gr33a is required for activating bitter-sensing gustatory receptor neurons by cucurbitacin B among available 26 Grs, 23 Irs, 11 Trp mutants, and 26 Gr-RNAi lines. We further investigated the difference between control and Gr33a mutant by analyzing binary food choice assay. We also measured toxic effect of Cucurbitacin B over 0.01 mM range. Our findings uncover the molecular sensor of cucurbitacin B in Drosophila melanogaster. We propose that the discarded shell of Cucurbitaceae can be developed to make a new insecticide.
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Affiliation(s)
- Suman Rimal
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Korea
| | - Jiun Sang
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Korea
| | - Subash Dhakal
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Korea
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