1
|
Asefa WR, Woo JN, Kim SY, Choi H, Sung H, Choi MS, Choi M, Yoon SE, Kim YJ, Suh BC, Kang K, Kwon JY. Molecular and cellular basis of sodium sensing in Drosophila labellum. iScience 2024; 27:110248. [PMID: 39015148 PMCID: PMC11250893 DOI: 10.1016/j.isci.2024.110248] [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: 11/12/2023] [Revised: 03/14/2024] [Accepted: 06/07/2024] [Indexed: 07/18/2024] Open
Abstract
Appropriate ingestion of salt is essential for physiological processes such as ionic homeostasis and neuronal activity. Generally, low concentrations of salt elicit attraction, while high concentrations elicit aversive responses. Here, we observed that sugar neurons in the L sensilla of the Drosophila labellum cf. responses to NaCl, while sugar neurons in the S-c sensilla do not respond to NaCl, suggesting that gustatory receptor neurons involved in NaCl sensing may employ diverse molecular mechanisms. Through an RNAi screen of the entire Ir and ppk gene families and molecular genetic approaches, we identified IR76b, IR25a, and IR56b as necessary components for NaCl sensing in the Drosophila labellum. Co-expression of these three IRs in heterologous systems such as S2 cells or Xenopus oocytes resulted in a current in response to sodium stimulation, suggesting formation of a sodium-sensing complex. Our results should provide insights for research on the diverse combinations constituting salt receptor complexes.
Collapse
Affiliation(s)
- Wayessa Rahel Asefa
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jin-Nyeong Woo
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Seon Yeong Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
- Neurovascular Unit Research Group, Korea Brain Research Institute, Daegu 41062, Republic of Korea
| | - Hyungjun Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hayeon Sung
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Molecular, Cellular and Developmental Biology, College of Literature, Science, and the Arts, The University of Michigan, Ann Arbor, USA
| | - Min Sung Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Minkook Choi
- Department of Oral Biology, Yonsei University College of Dentistry, Seoul 03722, Republic of Korea
| | - Sung-Eun Yoon
- Korea Drosophila Resource Center, Gwangju 61005, Republic of Korea
| | - Young-Joon Kim
- Korea Drosophila Resource Center, Gwangju 61005, Republic of Korea
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Byung-Chang Suh
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - KyeongJin Kang
- Neurovascular Unit Research Group, Korea Brain Research Institute, Daegu 41062, Republic of Korea
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea
| |
Collapse
|
2
|
Peláez JN, Bernstein S, Okoro J, Rodas E, Liang I, Leipertz A, Marion-Poll F, Whiteman NK. Taste evolution in an herbivorous drosophilid. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.582299. [PMID: 38464294 PMCID: PMC10925181 DOI: 10.1101/2024.02.27.582299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Plant secondary metabolites pose a challenge for generalist herbivorous insects because they are not only potentially toxic, they also may trigger aversion. On the contrary, some highly specialized herbivorous insects evolved to use these same compounds as 'token stimuli' for unambiguous determination of their host plants. Two questions that emerge from these observations are how recently derived herbivores evolve to overcome this aversion to plant secondary metabolites and the extent to which they evolve increased attraction to these same compounds. In this study, we addressed these questions by focusing on the evolution of bitter taste preferences in the herbivorous drosophilid Scaptomyza flava, which is phylogenetically nested deep in the paraphyletic Drosophila. We measured behavioral and neural responses of S. flava and a set of non-herbivorous species representing a phylogenetic gradient (S. pallida, S. hsui, and D. melanogaster) towards host- and non-host derived bitter plant compounds. We observed that S. flava evolved a shift in bitter detection, rather than a narrow shift towards glucosinolates, the precursors of mustard-specific defense compounds. In a dye-based consumption assay, S. flava exhibited shifts in aversion toward the non-mustard bitter, plant-produced alkaloids caffeine and lobeline, and reduced aversion towards glucosinolates, whereas the non-herbivorous species each showed strong aversion to all bitter compounds tested. We then examined whether these changes in bitter preferences of S. flava could be explained by changes in sensitivity in the peripheral nervous system and compared electrophysiological responses from the labellar sensilla of S. flava, S. pallida, and D. melanogaster. Using scanning electron microscopy, we also created a map of labellar sensilla in S. flava and S. pallida. We assigned each sensillum to a functional sensilla class based on their morphology and initial response profiles to bitter and sweet compounds. Despite a high degree of conservation in the morphology and spatial placement of sensilla between S. flava and S. pallida, electrophysiological studies revealed that S. flava had reduced sensitivity to glucosinolates to varying degrees. We found this reduction only in I type sensilla. Finally, we speculate on the potential role that evolutionary genetic changes in gustatory receptors between S. pallida and S. flava may play in driving these patterns. Specifically, we hypothesize that the evolution of bitter receptors expressed in I type sensilla may have driven the reduced sensitivity observed in S. flava, and ultimately, its reduced bitter aversion. The S. flava system showcases the importance of reduced aversion to bitter defense compounds in relatively young herbivorous lineages, and how this may be achieved at the molecular and physiological level.
Collapse
Affiliation(s)
- Julianne N. Peláez
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Susan Bernstein
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Judith Okoro
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Esteban Rodas
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Irene Liang
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Anna Leipertz
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Frédéric Marion-Poll
- Evolution, Genomes, Behaviour and Ecology, IDEEV, CNRS, Université Paris-Saclay, IRD, Gif-sur-Yvette, France
- Université Paris-Saclay, AgroParisTech, 91120 Palaiseau, France
| | - Noah K. Whiteman
- Department of Integrative Biology, University of California-Berkeley, Berkeley, CA 94720, USA
- Department of Molecular & Cellular Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| |
Collapse
|
3
|
Dweck HKM, Carlson JR. Diverse mechanisms of taste coding in Drosophila. SCIENCE ADVANCES 2023; 9:eadj7032. [PMID: 37976361 PMCID: PMC10656072 DOI: 10.1126/sciadv.adj7032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/18/2023] [Indexed: 11/19/2023]
Abstract
Taste systems encode chemical cues that drive vital behaviors. We have elucidated noncanonical features of taste coding using an unconventional kind of electrophysiological analysis. We find that taste neurons of Drosophila are much more sensitive than previously thought. They have a low spontaneous firing frequency that depends on taste receptors. Taste neurons have a dual function as olfactory neurons: They are activated by most tested odorants, including N,N-diethyl-meta-toluamide (DEET), at a distance. DEET can also inhibit certain taste neurons, revealing that there are two modes of taste response: activation and inhibition. We characterize electrophysiological OFF responses and find that the tastants that elicit them are related in structure. OFF responses link tastant identity to behavior: the magnitude of the OFF response elicited by a tastant correlated with the egg laying behavior it elicited. In summary, the sensitivity and coding capacity of the taste system are much greater than previously known.
Collapse
Affiliation(s)
- Hany K M Dweck
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Department of Entomology, The Connecticut Agricultural Experiment Station, New Haven, CT 06511, USA
| | - John R Carlson
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| |
Collapse
|
4
|
Pandey P, Shrestha B, Lee Y. Acid and Alkali Taste Sensation. Metabolites 2023; 13:1131. [PMID: 37999227 PMCID: PMC10673112 DOI: 10.3390/metabo13111131] [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: 09/19/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
Living organisms rely on pH levels for a multitude of crucial biological processes, such as the digestion of food and the facilitation of enzymatic reactions. Among these organisms, animals, including insects, possess specialized taste organs that enable them to discern between acidic and alkaline substances present in their food sources. This ability is vital, as the pH of these compounds directly influences both the nutritional value and the overall health impact of the ingested substances. In response to the various chemical properties of naturally occurring compounds, insects have evolved peripheral taste organs. These sensory structures play a pivotal role in identifying and distinguishing between nourishing and potentially harmful foods. In this concise review, we aim to provide an in-depth examination of the molecular mechanisms governing pH-dependent taste responses, encompassing both acidic and alkaline stimuli, within the peripheral taste organs of the fruit fly, Drosophila melanogaster, drawing insights from a comprehensive analysis of existing research articles.
Collapse
Affiliation(s)
| | | | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea; (P.P.); (B.S.)
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Wang W, Dweck HKM, Talross GJS, Zaidi A, Gendron JM, Carlson JR. Sugar sensation and mechanosensation in the egg-laying preference shift of Drosophila suzukii. eLife 2022; 11:e81703. [PMID: 36398882 PMCID: PMC9674340 DOI: 10.7554/elife.81703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022] Open
Abstract
The agricultural pest Drosophila suzukii differs from most other Drosophila species in that it lays eggs in ripe, rather than overripe, fruit. Previously, we showed that changes in bitter taste sensation accompanied this adaptation (Dweck et al., 2021). Here, we show that D. suzukii has also undergone a variety of changes in sweet taste sensation. D. suzukii has a weaker preference than Drosophila melanogaster for laying eggs on substrates containing all three primary fruit sugars: sucrose, fructose, and glucose. Major subsets of D. suzukii taste sensilla have lost electrophysiological responses to sugars. Expression of several key sugar receptor genes is reduced in the taste organs of D. suzukii. By contrast, certain mechanosensory channel genes, including no mechanoreceptor potential C, are expressed at higher levels in the taste organs of D. suzukii, which has a higher preference for stiff substrates. Finally, we find that D. suzukii responds differently from D. melanogaster to combinations of sweet and mechanosensory cues. Thus, the two species differ in sweet sensation, mechanosensation, and their integration, which are all likely to contribute to the differences in their egg-laying preferences in nature.
Collapse
Affiliation(s)
- Wanyue Wang
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| | - Hany KM Dweck
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| | - Gaëlle JS Talross
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| | - Ali Zaidi
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| | - Joshua M Gendron
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| | - John R Carlson
- Department of Molecular, Cellular and Developmental Biology, Yale UniversityNew HavenUnited States
| |
Collapse
|
9
|
Zhang S, Tang J, Li Y, Li D, Chen G, Chen L, Yang Z, He N. The silkworm gustatory receptor BmGr63 is dedicated to the detection of isoquercetin in mulberry. Proc Biol Sci 2022; 289:20221427. [DOI: 10.1098/rspb.2022.1427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Gustatory systems in phytophagous insects are used to perceive feeding stimulants and deterrents, and are involved in insect decisions to feed on particular plants. During the process, gustatory receptors (Grs) can recognize diverse phytochemicals and provide a molecular basis for taste perception. The silkworm, as a representative Lepidoptera species, has developed a strong feeding preference for mulberry leaves. The mulberry-derived flavonoid glycoside, isoquercetin, is required to induce feeding behaviours. However, the corresponding Grs for isoquercetin and underlying molecular mechanisms remain unclear. In this study, we used molecular methods, voltage clamp recordings and feeding assays to identify silkworm BmGr63, which was tuned to isoquercetin. The use of qRT-PCR confirmed that
BmGr63
was highly expressed in the mouthpart of fourth and fifth instar larvae. Functional analysis showed that oocytes expressing
BmGr63
from the ‘bitter’ clade responded to mulberry extracts. Among 20 test chemicals, BmGr63 specifically recognized isoquercetin. The preference for isoquercetin was not observed in
BmGr63
knock-down groups. The tuning between BmGr63 and isoquercetin has been demonstrated, which is meaningful to explain the silkworm-mulberry feeding mechanism from molecular levels and thus provides evidence for further feeding relationship studies between phytophagous insects and host plants.
Collapse
Affiliation(s)
- Shaoyu Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| | - Jiaqi Tang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| | - Yunfeng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| | - Dong Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| | - Guo Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| | - Lin Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| | - Zhen Yang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| | - Ningjia He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, People's Republic of China
| |
Collapse
|
10
|
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
Collapse
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
| | | |
Collapse
|
11
|
Pontes G, Latorre-Estivalis JM, Gutiérrez ML, Cano A, Berón de Astrada M, Lorenzo MG, Barrozo RB. Molecular and functional basis of high-salt avoidance in a blood-sucking insect. iScience 2022; 25:104502. [PMID: 35720264 PMCID: PMC9204723 DOI: 10.1016/j.isci.2022.104502] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/14/2022] [Accepted: 05/26/2022] [Indexed: 12/05/2022] Open
Abstract
Salts are essential nutrients required for many physiological processes, and accordingly, their composition and concentration are tightly regulated. Taste is the ultimate sensory modality involved in resource quality assessment, resulting in acceptance or rejection. Here we found that high salt concentrations elicit feeding avoidance in the blood-sucking bug Rhodnius prolixus and elucidate the molecular and neurophysiological mechanisms involved. We found that high-salt avoidance is mediated by a salt-sensitive antennal gustatory receptor neuron (GRN). Using RNAi, we demonstrate that this process requires two amiloride-sensitive pickpocket channels (PPKs; RproPPK014276 and RproPPK28) expressed within these cells. We found that antennal GRNs project to the insect primary olfactory center, the antennal lobes, revealing these centers as potential sites for the integration of taste and olfactory host-derived cues. Moreover, the identification of the gustatory basis of high-salt detection in a hematophagous insect suggests novel targets for the prevention of biting and feeding. High-salt sensing prevents biting and feeding in a blood-sucking insect High-salt avoidance is mediated by an antennal gustatory receptor neuron Two PPK receptors, RproPPK014276 and RproPPK28, are required for high-salt detection RproPPK014276 and RproPPK28 are sensitive to amiloride blockade
Collapse
|
12
|
Dweck HK, Talross GJ, Luo Y, Ebrahim SA, Carlson JR. Ir56b is an atypical ionotropic receptor that underlies appetitive salt response in Drosophila. Curr Biol 2022; 32:1776-1787.e4. [PMID: 35294865 PMCID: PMC9050924 DOI: 10.1016/j.cub.2022.02.063] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 02/08/2022] [Accepted: 02/22/2022] [Indexed: 01/28/2023]
Abstract
Salt taste is one of the most ancient of all sensory modalities. However, the molecular basis of salt taste remains unclear in invertebrates. Here, we show that the response to low, appetitive salt concentrations in Drosophila depends on Ir56b, an atypical member of the ionotropic receptor (Ir) family. Ir56b acts in concert with two coreceptors, Ir25a and Ir76b. Mutation of Ir56b virtually eliminates an appetitive behavioral response to salt. Ir56b is expressed in neurons that also sense sugars via members of the Gr (gustatory receptor) family. Misexpression of Ir56b in bitter-sensing neurons confers physiological responses to appetitive doses of salt. Ir56b is unique among tuning Irs in containing virtually no N-terminal region, a feature that is evolutionarily conserved. Moreover, Ir56b is a "pseudo-pseudogene": its coding sequence contains a premature stop codon that can be replaced with a sense codon without loss of function. This stop codon is conserved among many Drosophila species but is absent in a number of species associated with cactus in arid regions. Thus, Ir56b serves the evolutionarily ancient function of salt detection in neurons that underlie both salt and sweet taste modalities.
Collapse
|
13
|
Drosophila melanogaster Chemosensory Pathways as Potential Targets to Curb the Insect Menace. INSECTS 2022; 13:insects13020142. [PMID: 35206716 PMCID: PMC8874460 DOI: 10.3390/insects13020142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary The perception and processing of chemosensory stimuli are indispensable to the survival of living organisms. In insects, olfaction and gustation play a critical role in seeking food, finding mates and avoiding signs of danger. This review aims to present updated information about olfactory and gustatory signaling in the fruit fly Drosophila melanogaster. We have described the mechanisms involved in olfactory and gustatory perceptions at the molecular level, the receptors along with the allied molecules involved, and their signaling pathways in the fruit fly. Due to the magnifying problems of disease-causing insect vectors and crop pests, the applications of chemosensory signaling in controlling pests and insect vectors are also discussed. Abstract From a unicellular bacterium to a more complex human, smell and taste form an integral part of the basic sensory system. In fruit flies Drosophila melanogaster, the behavioral responses to odorants and tastants are simple, though quite sensitive, and robust. They explain the organization and elementary functioning of the chemosensory system. Molecular and functional analyses of the receptors and other critical molecules involved in olfaction and gustation are not yet completely understood. Hence, a better understanding of chemosensory cue-dependent fruit flies, playing a major role in deciphering the host-seeking behavior of pathogen transmitting insect vectors (mosquitoes, sandflies, ticks) and crop pests (Drosophila suzukii, Queensland fruit fly), is needed. Using D. melanogaster as a model organism, the knowledge gained may be implemented to design new means of controlling insects as well as in analyzing current batches of insect and pest repellents. In this review, the complete mechanisms of olfactory and gustatory perception, along with their implementation in controlling the global threat of disease-transmitting insect vectors and crop-damaging pests, are explained in fruit flies.
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Zhou DS, Wang CZ, van Loon JJA. Habituation to a Deterrent Plant Alkaloid Develops Faster in the Specialist Herbivore Helicoverpa assulta Than in Its Generalist Congener Helicoverpa armigera and Coincides with Taste Neuron Desensitisation. INSECTS 2021; 13:21. [PMID: 35055863 PMCID: PMC8779340 DOI: 10.3390/insects13010021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 11/17/2022]
Abstract
The two closely related moth species, Helicoverpa armigera and H. assulta differ strongly in their degree of host-plant specialism. In dual-choice leaf disk assays, caterpillars of the two species that had been reared on standard artificial diet were strongly deterred by the plant-derived alkaloid strychnine. However, caterpillars of both species reared on artificial diet containing strychnine from neonate to the 5th instar were insensitive to this compound. Fifth instar caterpillars of H. assulta and 4th or 5th instars of H. armigera not exposed to strychnine before were subjected to strychnine-containing diet for 24 h, 36 h, 48 h, or 72 h. Whereas H. assulta displayed habituation to strychnine after 48 h, it took until 72 h for H. armigera to become habituated. Electrophysiological tests revealed that a deterrent-sensitive neuron in the medial sensillum styloconicum of both species displayed significantly reduced sensitivity to strychnine that correlated with the onset of habituation. We conclude that the specialist H. assulta habituated faster to strychnine than the generalist H. armigera and hypothesis that desensitization of deterrent-sensitive neurons contributed to habituation.
Collapse
Affiliation(s)
- Dong-Sheng Zhou
- Hunan Key Laboratory for Conservation and Utilization of Biological Resources in the Nanyue Mountainous Region, College of Life Sciences and Environment, Hengyang Normal University, Hengyang 421008, China;
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Laboratory of Entomology, Wageningen University, 6700 AA Wageningen, The Netherlands
| | - Chen-Zhu Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Joop J. A. van Loon
- Laboratory of Entomology, Wageningen University, 6700 AA Wageningen, The Netherlands
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
Devineni AV, Deere JU, Sun B, Axel R. Individual bitter-sensing neurons in Drosophila exhibit both ON and OFF responses that influence synaptic plasticity. Curr Biol 2021; 31:5533-5546.e7. [PMID: 34731675 DOI: 10.1016/j.cub.2021.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/04/2021] [Accepted: 10/08/2021] [Indexed: 01/07/2023]
Abstract
The brain generates internal representations that translate sensory stimuli into appropriate behavior. In the taste system, different tastes activate distinct populations of sensory neurons. We investigated the temporal properties of taste responses in Drosophila and discovered that different types of taste sensory neurons show striking differences in their response dynamics. Strong responses to stimulus onset (ON responses) and offset (OFF responses) were observed in bitter-sensing neurons in the labellum, whereas bitter neurons in the leg and other classes of labellar taste neurons showed only an ON response. Individual labellar bitter neurons generate both ON and OFF responses through a cell-intrinsic mechanism that requires canonical bitter receptors. A single receptor complex likely generates both ON and OFF responses to a given bitter ligand. These ON and OFF responses in the periphery are propagated to dopaminergic neurons that mediate aversive learning, and the presence of the OFF response impacts synaptic plasticity when bitter is used as a reinforcement cue. These studies reveal previously unknown features of taste responses that impact neural circuit function and may be important for behavior. Moreover, these studies show that OFF responses can dramatically influence timing-based synaptic plasticity, which is thought to underlie associative learning.
Collapse
Affiliation(s)
- Anita V Devineni
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA.
| | - Julia U Deere
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA
| | - Bei Sun
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA
| | - Richard Axel
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA.
| |
Collapse
|
18
|
Wang Y, Shi J, Cui H, Wang CZ, Zhao Z. Effects of NPF on larval taste responses and feeding behaviors in Ostrinia furnacalis. JOURNAL OF INSECT PHYSIOLOGY 2021; 133:104276. [PMID: 34245800 DOI: 10.1016/j.jinsphys.2021.104276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/23/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
The insect taste system regulates insect feeding behavior and patterns of food consumption. In this study, we showed that the medial and lateral sensilla styloconica in the mouthparts of 5th-instar Asian corn borer larvae are sensitive to fructose and sucrose in a concentration-dependent way. The two sensilla produced significant electrophysiological responses (greater than100 spikes/s) by exposure to 10 mM fructose or sucrose. However, electrophysiological responses and feeding preferences to fructose or sucrose were inhibited by neuropeptide F double-stranded RNA (dsNPF). Additionally, the medial sensilla styloconica are sensitive to low concentrations of the deterrents caffeine and nicotine. However, starvation, followed by increases in larval npf expression plus feeding, led to increases in spike frequencies of related sensilla to fructose, sucrose, and deterrents. In contrast, these responses were reduced on the dsNPF treatment. Our results suggest that NPF plays an important role influencing caterpillar feeding behavior through regulating the taste neurons of the sensilla styloconica.
Collapse
Affiliation(s)
- Yuan Wang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Jian Shi
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Hongying Cui
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Chen-Zhu Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Zhangwu Zhao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China.
| |
Collapse
|
19
|
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.
Collapse
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.
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
Puri S, Lee Y. Salt Sensation and Regulation. Metabolites 2021; 11:metabo11030175. [PMID: 33802977 PMCID: PMC8002656 DOI: 10.3390/metabo11030175] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/08/2021] [Accepted: 03/15/2021] [Indexed: 12/02/2022] Open
Abstract
Taste sensation and regulation are highly conserved in insects and mammals. Research conducted over recent decades has yielded major advances in our understanding of the molecular mechanisms underlying the taste sensors for a variety of taste sensations and the processes underlying regulation of ingestion depending on our internal state. Salt (NaCl) is an essential ingested nutrient. The regulation of internal sodium concentrations for physiological processes, including neuronal activity, fluid volume, acid–base balance, and muscle contraction, are extremely important issues in animal health. Both mammals and flies detect low and high NaCl concentrations as attractive and aversive tastants, respectively. These attractive or aversive behaviors can be modulated by the internal nutrient state. However, the differential encoding of the tastes underlying low and high salt concentrations in the brain remain unclear. In this review, we discuss the current view of taste sensation and modulation in the brain with an emphasis on recent advances in this field. This work presents new questions that include but are not limited to, “How do the fly’s neuronal circuits process this complex salt code?” and “Why do high concentrations of salt induce a negative valence only when the need for salt is low?” A better understanding of regulation of salt homeostasis could improve our understanding of why our brains enjoy salty food so much.
Collapse
Affiliation(s)
- Sonali Puri
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul 02707, Korea;
| | - Youngseok Lee
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul 02707, Korea;
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
- Correspondence: ; Tel.: +82-2-910-5734
| |
Collapse
|
22
|
Li L, Gao X, Gui H, Lan M, Zhu J, Xie Y, Zhan Y, Wang Z, Li Z, Ye M, Wu G. Identification and preliminary characterization of chemosensory-related proteins in the gall fly, Procecidochares utilis by transcriptomic analysis. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 36:100724. [PMID: 32836214 DOI: 10.1016/j.cbd.2020.100724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/24/2020] [Accepted: 08/05/2020] [Indexed: 01/20/2023]
Abstract
Chemoreception is critical for insect behaviors such as foraging, host searching and oviposition. The process of chemoreception is mediated by a series of proteins, including odorant-binding proteins (OBPs), gustatory receptors (GRs), odorant receptors (ORs), ionotropic receptors (IRs), chemosensory proteins (CSPs) and sensory neuron membrane proteins (SNMPs). The tephritid stem gall fly, Procecidochares utilis Stone, is a type of egg parasitic insect, which is an effective biological control agent for the invasive weed Ageratina adenophora in many countries. However, the study of molecular components related to the olfactory system of P. utilis has not been investigated. Here, we conducted the developmental transcriptome (egg, first-third instar larva, pupa, female and male adult) of P. utilis using next-generation sequencing technology and identified a total of 133 chemosensory genes, including 40 OBPs, 29 GRs, 24 ORs, 28 IRs, 6 CSPs, and 6 SNMPs. The sequences of these candidate chemosensory genes were confirmed by BLAST, and phylogenetic analysis was performed. Quantitative real-time PCR (qRT-PCR) confirmed that the expression levels of the candidate OBPs varied at the different developmental stages of P. utilis with most OBPs expressed mainly in the pupae, female and male adults but scarcely in eggs and larvae, which was consistent with the differentially expressed genes (DEGs) analysis using the fragments per kilobase per million fragments (FPKM) value. Our results provide a significant contribution towards the knowledge of the set of chemosensory proteins and help advance the use of P. utilis as biological control agents.
Collapse
Affiliation(s)
- Lifang Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Xi Gao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Huamin Gui
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Mingxian Lan
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Jiaying Zhu
- Key Laboratory of Forest Disaster Warning and Control of Yunnan Province, Southwest Forestry University, Kunming 650224, China
| | - Yonghui Xie
- Kunming Branch of Yunnan Provincial Tobacco Company, Kunming 650021, China
| | - Youguo Zhan
- Kunming Branch of Yunnan Provincial Tobacco Company, Kunming 650021, China
| | - Zhijiang Wang
- Kunming Branch of Yunnan Provincial Tobacco Company, Kunming 650021, China
| | - Zhengyue Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Min Ye
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China.
| | - Guoxing Wu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China.
| |
Collapse
|
23
|
Ng R, Wu ST, Su CY. Neuronal Compartmentalization: A Means to Integrate Sensory Input at the Earliest Stage of Information Processing? Bioessays 2020; 42:e2000026. [PMID: 32613656 PMCID: PMC7864560 DOI: 10.1002/bies.202000026] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/20/2020] [Indexed: 01/08/2023]
Abstract
In numerous peripheral sense organs, external stimuli are detected by primary sensory neurons compartmentalized within specialized structures composed of cuticular or epithelial tissue. Beyond reflecting developmental constraints, such compartmentalization also provides opportunities for grouped neurons to functionally interact. Here, the authors review and illustrate the prevalence of these structural units, describe characteristics of compartmentalized neurons, and consider possible interactions between these cells. This article discusses instances of neuronal crosstalk, examples of which are observed in the vertebrate tastebuds and multiple types of arthropod chemosensory hairs. Particular attention is paid to insect olfaction, which presents especially well-characterized mechanisms of functional, cross-neuronal interactions. These examples highlight the potential impact of peripheral processing, which likely contributes more to signal integration than previously considered. In surveying a wide variety of structural units, it is hoped that this article will stimulate future research that determines whether grouped neurons in other sensory systems can also communicate to impact information processing.
Collapse
Affiliation(s)
| | | | - Chih-Ying Su
- Neurobiology Section, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
24
|
Rimal S, Sang J, Poudel S, Thakur D, Montell C, Lee Y. Mechanism of Acetic Acid Gustatory Repulsion in Drosophila. Cell Rep 2020; 26:1432-1442.e4. [PMID: 30726729 DOI: 10.1016/j.celrep.2019.01.042] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 11/07/2018] [Accepted: 01/10/2019] [Indexed: 12/01/2022] Open
Abstract
The decision to consume or reject a food based on the degree of acidity is critical for animal survival. However, the gustatory receptors that detect sour compounds and influence feeding behavior have been elusive. Here, using the fly, Drosophila melanogaster, we reveal that a member of the ionotropic receptor family, IR7a, is essential for rejecting foods laced with high levels of acetic acid. IR7a is dispensable for repulsion of other acidic compounds, indicating that the gustatory sensation of acids occurs through a repertoire rather than a single receptor. The fly's main taste organ, the labellum, is decorated with bristles that house dendrites of gustatory receptor neurons (GRNs). IR7a is expressed in a subset of bitter GRNs rather than GRNs dedicated to sour taste. Our findings indicate that flies taste acids through a repertoire of receptors, enabling them to discriminate foods on the basis of acid composition rather than just pH.
Collapse
Affiliation(s)
- Suman Rimal
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Republic of Korea
| | - Jiun Sang
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Republic of Korea
| | - Seeta Poudel
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Republic of Korea
| | - Dhananjay Thakur
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Craig Montell
- Department of Molecular, Cellular, and Developmental Biology and the Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 02707, Republic of Korea.
| |
Collapse
|
25
|
CCAP regulates feeding behavior via the NPF pathway in Drosophila adults. Proc Natl Acad Sci U S A 2020; 117:7401-7408. [PMID: 32179671 DOI: 10.1073/pnas.1914037117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The intake of macronutrients is crucial for the fitness of any animal and is mainly regulated by peripheral signals to the brain. How the brain receives and translates these peripheral signals or how these interactions lead to changes in feeding behavior is not well-understood. We discovered that 2 crustacean cardioactive peptide (CCAP)-expressing neurons in Drosophila adults regulate feeding behavior and metabolism. Notably, loss of CCAP, or knocking down the CCAP receptor (CCAP-R) in 2 dorsal median neurons, inhibits the release of neuropeptide F (NPF), which regulates feeding behavior. Furthermore, under starvation conditions, flies normally have an increased sensitivity to sugar; however, loss of CCAP, or CCAP-R in 2 dorsal median NPF neurons, inhibited sugar sensitivity in satiated and starved flies. Separate from its regulation of NPF signaling, the CCAP peptide also regulates triglyceride levels. Additionally, genetic and optogenetic studies demonstrate that CCAP signaling is necessary and sufficient to stimulate a reflexive feeding behavior, the proboscis extension reflex (PER), elicited when external food cues are interpreted as palatable. Dopaminergic signaling was also sufficient to induce a PER. On the other hand, although necessary, NPF neurons were not able to induce a PER. These data illustrate that the CCAP peptide is a central regulator of feeding behavior and metabolism in adult flies, and that NPF neurons have an important regulatory role within this system.
Collapse
|
26
|
Chen YCD, Dahanukar A. Recent advances in the genetic basis of taste detection in Drosophila. Cell Mol Life Sci 2020; 77:1087-1101. [PMID: 31598735 PMCID: PMC7125039 DOI: 10.1007/s00018-019-03320-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/10/2019] [Accepted: 09/23/2019] [Indexed: 01/05/2023]
Abstract
The insect gustatory system senses taste information from environmental food substrates and processes it to control feeding behaviors. Drosophila melanogaster has been a powerful genetic model for investigating how various chemical cues are detected at the molecular and cellular levels. In addition to an understanding of how tastants belonging to five historically described taste modalities (sweet, bitter, acid, salt, and amino acid) are sensed, recent findings have identified taste neurons and receptors that recognize tastants of non-canonical modalities, including fatty acids, carbonated water, polyamines, H2O2, bacterial lipopolysaccharide (LPS), ammonia, and calcium. Analyses of response profiles of taste neurons expressing different suites of chemosensory receptors have allowed exploration of taste coding mechanisms in primary sensory neurons. In this review, we present the current knowledge of the molecular and cellular basis of taste detection of various categories of tastants. We also summarize evidence for organotopic and multimodal functions of the taste system. Functional characterization of peripheral taste neurons in different organs has greatly increased our understanding of how insect behavior is regulated by the gustatory system, which may inform development of novel insect pest control strategies.
Collapse
Affiliation(s)
- Yu-Chieh David Chen
- Interdepartmental Neuroscience Program, University of California, Riverside, CA, 92521, USA
| | - Anupama Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, CA, 92521, USA.
- Department of Molecular, Cell and Systems Biology, University of California, 900 University Avenue, Riverside, CA, 92521, USA.
| |
Collapse
|
27
|
Masagué S, Cano A, Asparch Y, Barrozo RB, Minoli S. Sensory discrimination between aversive salty and bitter tastes in an haematophagous insect. Eur J Neurosci 2020; 51:1867-1880. [PMID: 32048391 DOI: 10.1111/ejn.14702] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 02/07/2020] [Accepted: 02/09/2020] [Indexed: 12/31/2022]
Abstract
Sensory aversion is essential for avoiding prospective dangers. We studied the chemical perception of aversive compounds of different gustatory modalities (salty, bitter) in the haematophagous bug, Rhodnius prolixus. Over a walking arena, insects avoided a substrate embedded with 1M NaCl or KCl if provided with water as an alternative. However, no preferences were expressed when both salts were opposed to each other. A pre-exposure to amiloride interfered with the repellency of NaCl and KCl equally, suggesting that amiloride-sensitive receptors are involved in the detection of both salts. Discriminative experiments were then performed to determine whether R. prolixus can distinguish between these salts. An aversive operant conditioning involving either NaCl or KCl modulated the repellency of the conditioned salt, but also of the novel salt. Repellency levels of both salts were rigid to a chemical pre-exposure to any of both salts. When gustatory modalities were crossed by presenting as a choice NaCl and a bitter molecule as caffeine (Caf), no innate preferences were expressed. Aversive operant conditionings with either NaCl or Caf rendered unspecific changes in the repellency of both compounds. A chemical pre-exposure to Caf modulated the response to Caf but not to NaCl, suggesting the existence of two independent neural pathways for the detection of salts and bitter compounds. Overall results suggest that R. prolixus cannot discriminate molecules of the same gustatory modality (i.e. salty), but can distinguish between salty and bitter tastes. The potential use of aversive gustatory stimuli as a complement of commercially available olfactory repellents is discussed.
Collapse
Affiliation(s)
- Santiago Masagué
- Laboratorio Fisiología de Insectos, Instituto Biodiversidad Biología Experimental Aplicada, CONICET - UBA, Departamento Biodiversidad Biología Experimental, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Agustina Cano
- Laboratorio Fisiología de Insectos, Instituto Biodiversidad Biología Experimental Aplicada, CONICET - UBA, Departamento Biodiversidad Biología Experimental, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Yamila Asparch
- Laboratorio Fisiología de Insectos, Instituto Biodiversidad Biología Experimental Aplicada, CONICET - UBA, Departamento Biodiversidad Biología Experimental, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Romina B Barrozo
- Laboratorio Fisiología de Insectos, Instituto Biodiversidad Biología Experimental Aplicada, CONICET - UBA, Departamento Biodiversidad Biología Experimental, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Sebastian Minoli
- Laboratorio Fisiología de Insectos, Instituto Biodiversidad Biología Experimental Aplicada, CONICET - UBA, Departamento Biodiversidad Biología Experimental, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| |
Collapse
|
28
|
Toshima N, Kantar Weigelt M, Weiglein A, Boetzl FA, Gerber B. An amino-acid mixture can be both rewarding and punishing to larval Drosophila melanogaster. ACTA ACUST UNITED AC 2019; 222:jeb.209486. [PMID: 31672727 DOI: 10.1242/jeb.209486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/24/2019] [Indexed: 12/17/2022]
Abstract
Amino acids are important nutrients for animals because they are necessary for protein synthesis in particular during growth, as well as for neurotransmission. However, little is known about how animals use past experience to guide their search for amino-acid-rich food. We reasoned that the larvae of Drosophila melanogaster are suitable for investigating this topic because they are the feeding and growth stages in the life cycle of these holometabolous insects. Specifically, we investigated whether experiencing an odour with a 20 amino-acid mixture as a semi-natural tastant during training establishes odour-tastant associative memories. Across a broad concentration range (0.01-20 mmol l-1), such an amino-acid mixture was found to have a rewarding effect, establishing appetitive memory for the odour. To our surprise, however, manipulation of the test conditions revealed that relatively high concentrations of the amino-acid mixture (3.3 mmol l-1 and higher) in addition establish aversive memory for the odour. We then characterized both of these oppositely valenced memories in terms of their dependency on the number of training trials, their temporal stability, their modulation through starvation and the specific changes in locomotion underlying them. Collectively, and in the light of what is known about the neuronal organization of odour-food memory in larval D . melanogaster, our data suggest that these memories are established in parallel. We discuss the similarity of our results to what has been reported for sodium chloride, and the possible neurogenetic bases for concentration-dependent changes in valence when these tastants are used as reinforcers.
Collapse
Affiliation(s)
- Naoko Toshima
- Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology (LIN), Brenneckestrasse 6, 39118 Magdeburg, Germany
| | - Melisa Kantar Weigelt
- Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology (LIN), Brenneckestrasse 6, 39118 Magdeburg, Germany
| | - Aliće Weiglein
- Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology (LIN), Brenneckestrasse 6, 39118 Magdeburg, Germany
| | - Fabian A Boetzl
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Bertram Gerber
- Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology (LIN), Brenneckestrasse 6, 39118 Magdeburg, Germany.,Institute for Biology, Otto von Guericke University Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
| |
Collapse
|
29
|
Rihani K, Fraichard S, Chauvel I, Poirier N, Delompré T, Neiers F, Tanimura T, Ferveur JF, Briand L. A conserved odorant binding protein is required for essential amino acid detection in Drosophila. Commun Biol 2019; 2:425. [PMID: 31799428 PMCID: PMC6874667 DOI: 10.1038/s42003-019-0673-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 11/01/2019] [Indexed: 11/10/2022] Open
Abstract
Animals need to detect in the food essential amino acids that they cannot synthesize. We found that the odorant binding protein OBP19b, which is highly expressed in Drosophila melanogaster taste sensilla, is necessary for the detection of several amino acids including the essential l-phenylalanine. The recombinant OBP19b protein was produced and characterized for its binding properties: it stereoselectively binds to several amino acids. Using a feeding-choice assay, we found that OBP19b is necessary for detecting l-phenylalanine and l-glutamine, but not l-alanine or D-phenylalanine. We mapped the cells expressing OBP19b and compared the electrophysiological responses of a single taste sensillum to several amino acids: OBP19b mutant flies showed a reduced response compared to control flies when tested to preferred amino acids, but not to the other ones. OBP19b is well conserved in phylogenetically distant species suggesting that this protein is necessary for detection of specific amino acids in insects.
Collapse
Affiliation(s)
- Karen Rihani
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| | - Stéphane Fraichard
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| | - Isabelle Chauvel
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| | - Nicolas Poirier
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| | - Thomas Delompré
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| | - Fabrice Neiers
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| | - Teiichi Tanimura
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Aichi 464-8602 Japan
- Department of Genetics, Leibniz Institute for Neurobiology (LIN), Brenneckestrasse 6, 39118 Magdeburg, Germany
| | - Jean-François Ferveur
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| | - Loïc Briand
- AgroSup Dijon, CNRS, INRA, Université de Bourgogne-Franche Comté, Centre des Sciences du Goût et de l’Alimentation, 21000 Dijon, France
| |
Collapse
|
30
|
Rimal S, Lee Y. Molecular sensor of nicotine in taste of Drosophila melanogaster. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 111:103178. [PMID: 31226410 DOI: 10.1016/j.ibmb.2019.103178] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/10/2019] [Accepted: 06/17/2019] [Indexed: 06/09/2023]
Abstract
Nicotine is an alkaloid and potent parasympathomimetic stimulant found in the leaves of many plants including Nicotiana tabacum, which functions as an anti-herbivore chemical and an insecticide. Chemoreceptors embedded in the gustatory receptor neurons (GRNs) enable animals to judge the quality of bitter compounds and respond to them. Various taste receptors such as gustatory receptors (GRs), ionotropic receptors (IRs), transient receptor potential channels (TRPs), and pickpocket channels (PPKs) have been shown to have important roles in taste sensation. However, the mechanism underlying nicotine taste sensation has not been resolved in the insect model. Here we identify molecular receptors to detect the taste of nicotine and provide electrophysiological and behavioral evidence that gustatory receptors are required for avoiding nicotine-laced foods. Our results demonstrate that gustatory receptors are reasonable targets to develop new pesticides that maximize the insecticidal effects of nicotine.
Collapse
Affiliation(s)
- Suman Rimal
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul, 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul, 02707, Republic of Korea.
| |
Collapse
|
31
|
Yanagawa A, Couto A, Sandoz JC, Hata T, Mitra A, Ali Agha M, Marion-Poll F. LPS perception through taste-induced reflex in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2019; 112:39-47. [PMID: 30528842 DOI: 10.1016/j.jinsphys.2018.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/07/2018] [Accepted: 12/02/2018] [Indexed: 06/09/2023]
Abstract
In flies, grooming serves several purposes, including protection against pathogens and parasites. Previously, we found Escherichia coli or lipopolysaccharides (LPS) can induce grooming behavior via activation of contact chemoreceptors on Drosophila wing. This suggested that specific taste receptors may contribute to this detection. In this study, we examined the perception of commercially available LPS on Drosophila wing chemoreceptors in grooming reflex. Behavioral tests conducted with bitter, sweet and salty gustation such as caffeine, sucrose and salt, using flies carrying a defect in one of their taste receptors related to the detection of bitter molecules (Gr66a, Gr33a), sugars (Gr5a, Gr64f), or salt (IR76b). LPS and tastants of each category were applied to wing sensilla of these taste defectflies and to wild-type Canton Special (CS) flies. Our results indicate that the grooming reflex induced by LPS requires a wide range of gustatory genes, and the inactivation of any of tested genes expressing cells causes a significant reduction of the behavior. This suggests that, while the grooming reflex is strongly regulated by cues perceived as aversive, other sapid cues traditionally related to sweet and salty tastes are also contributing to this behavior.
Collapse
Affiliation(s)
- Aya Yanagawa
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan.
| | - Antoine Couto
- UMR Evolution, Génomes, Comportement, Ecologie, CNRS, IRD, Univ Paris-Sud, Université Paris-Saclay, F-91198 Gif-sur-Yvette, France
| | - Jean-Christophe Sandoz
- UMR Evolution, Génomes, Comportement, Ecologie, CNRS, IRD, Univ Paris-Sud, Université Paris-Saclay, F-91198 Gif-sur-Yvette, France
| | - Toshimitsu Hata
- Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
| | - Aniruddha Mitra
- UMR Evolution, Génomes, Comportement, Ecologie, CNRS, IRD, Univ Paris-Sud, Université Paris-Saclay, F-91198 Gif-sur-Yvette, France; School of Biological & Environmental Sciences, Shoolini University, Solan, India
| | - Moutaz Ali Agha
- AgroParisTech, Université Paris-Saclay, Paris, France; Ÿnsect-Pôle Innovia, Damparis, France
| | - Frédéric Marion-Poll
- UMR Evolution, Génomes, Comportement, Ecologie, CNRS, IRD, Univ Paris-Sud, Université Paris-Saclay, F-91198 Gif-sur-Yvette, France; AgroParisTech, Université Paris-Saclay, Paris, France.
| |
Collapse
|
32
|
Kaushik S, Kumar R, Kain P. Salt an Essential Nutrient: Advances in Understanding Salt Taste Detection Using Drosophila as a Model System. J Exp Neurosci 2018; 12:1179069518806894. [PMID: 30479487 PMCID: PMC6249657 DOI: 10.1177/1179069518806894] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 09/19/2018] [Indexed: 11/16/2022] Open
Abstract
Taste modalities are conserved in insects and mammals. Sweet gustatory signals evoke attractive behaviors while bitter gustatory information drive aversive behaviors. Salt (NaCl) is an essential nutrient required for various physiological processes, including electrolyte homeostasis, neuronal activity, nutrient absorption, and muscle contraction. Not only mammals, even in Drosophila melanogaster, the detection of NaCl induces two different behaviors: Low concentrations of NaCl act as an attractant, whereas high concentrations act as repellant. The fruit fly is an excellent model system for studying the underlying mechanisms of salt taste due to its relatively simple neuroanatomical organization of the brain and peripheral taste system, the availability of powerful genetic tools and transgenic strains. In this review, we have revisited the literature and the information provided by various laboratories using invertebrate model system Drosophila that has helped us to understand NaCl salt taste so far. We hope that this compiled information from Drosophila will be of general significance and interest for forthcoming studies of the structure, function, and behavioral role of NaCl-sensitive (low and high concentrations) gustatory circuitry for understanding NaCl salt taste in all animals.
Collapse
Affiliation(s)
- Shivam Kaushik
- Department of Neurobiology and Genetics, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India
| | - Rahul Kumar
- Department of Neurobiology and Genetics, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India.,Department of Biotechnology, Maharshi Dayanand University, Rohtak, India
| | - Pinky Kain
- Department of Neurobiology and Genetics, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India
| |
Collapse
|
33
|
Jaeger AH, Stanley M, Weiss ZF, Musso PY, Chan RC, Zhang H, Feldman-Kiss D, Gordon MD. A complex peripheral code for salt taste in Drosophila. eLife 2018; 7:37167. [PMID: 30307393 PMCID: PMC6181562 DOI: 10.7554/elife.37167] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 09/14/2018] [Indexed: 01/20/2023] Open
Abstract
Each taste modality is generally encoded by a single, molecularly defined, population of sensory cells. However, salt stimulates multiple taste pathways in mammals and insects, suggesting a more complex code for salt taste. Here, we examine salt coding in Drosophila. After creating a comprehensive molecular map comprised of five discrete sensory neuron classes across the fly labellum, we find that four are activated by salt: two exhibiting characteristics of ‘low salt’ cells, and two ‘high salt’ classes. Behaviorally, low salt attraction depends primarily on ‘sweet’ neurons, with additional input from neurons expressing the ionotropic receptor IR94e. High salt avoidance is mediated by ‘bitter’ neurons and a population of glutamatergic neurons expressing Ppk23. Interestingly, the impact of these glutamatergic neurons depends on prior salt consumption. These results support a complex model for salt coding in flies that combinatorially integrates inputs from across cell types to afford robust and flexible salt behaviors. Salt is essential for our survival, but too much can kill us. Our taste system has therefore evolved two different pathways to help us maintain balance. Low concentrations (like the salt on our chips) activate a pathway that makes us want to eat. But high concentrations (like the salt in seawater) activate pathways that do the opposite. The nervous system takes on the role of detecting salt and encoding the information in a way that the brain can use. One specific type of cell detects each of the four other tastes: sweet, bitter, sour, and umami. But salt, with its two sensing pathways, is the exception to this rule. Previous work has examined salt taste responses in flies, but the picture is incomplete. In flies, one type of taste neuron uses a different signaling mechanism to the others, suggesting that it might play a special role. So here, Jaeger, Stanley et al. asked how fly sensory cells encode salt information for the brain, and what those unusual neurons are for. Mapping the taste receptor neurons in the tongue-like structure of the fly, the proboscis, revealed that salt information is not restricted to one or two types of cell. In fact, all five types of neurons tested (covering more than 90% of all the taste neurons present in flies) responded to salt in some way. Of these, two ‘low salt’ cell types made the fly want to eat salt, and two ‘high salt’ cell types made the fly want to avoid it. One of these high salt cell types was the unusual taste neuron identified previously. Rather than always encoding high salt as 'bad', the message from this type of cell changed depending on the diet of the fly. Salt-deprived flies ignored the activity of that cell type altogether. This complex way of encoding taste allowed the fly to change its behavior depending on how much salt it needed. This work opens new questions, like how do the fly's neuronal circuits process this complex salt code? And how do the ‘high salt’ cells achieve their negative effect only when the need for salt is low? Understanding more about this system could lead to a better understanding of why our own brains enjoy salty foods so much.
Collapse
Affiliation(s)
- Alexandria H Jaeger
- Department of Zoology, University of British Columbia, Vancouver, Canada.,Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Molly Stanley
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Zachary F Weiss
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Pierre-Yves Musso
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Rachel Cw Chan
- Engineering Physics Program, University of British Columbia, Vancouver, Canada
| | - Han Zhang
- Engineering Physics Program, University of British Columbia, Vancouver, Canada
| | | | - Michael D Gordon
- Department of Zoology, University of British Columbia, Vancouver, Canada
| |
Collapse
|
34
|
Gonzalez D, Fraichard S, Grassein P, Delarue P, Senet P, Nicolaï A, Chavanne E, Mucher E, Artur Y, Ferveur JF, Heydel JM, Briand L, Neiers F. Characterization of a Drosophila glutathione transferase involved in isothiocyanate detoxification. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 95:33-43. [PMID: 29578047 DOI: 10.1016/j.ibmb.2018.03.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/16/2018] [Accepted: 03/16/2018] [Indexed: 05/20/2023]
Abstract
Glutathione transferases (GSTs) are ubiquitous key enzymes that catalyse the conjugation of glutathione to xenobiotic compounds in the detoxification process. GSTs have been proposed to play a dual role in the signal termination of insect chemodetection by modifying odorant and tasting molecules and by protecting the chemosensory system. Among the 40 GSTs identified in Drosophila melanogaster, the Delta and Epsilon groups are insect-specific. GSTs Delta and Epsilon may have evolved to serve in detoxification, and have been associated with insecticide resistance. Here, we report the heterologous expression and purification of the D. melanogaster GST Delta 2 (GSTD2). We investigated the capacity of GSTD2 to bind tasting molecules. Among them, we found that isothiocyanates (ITC), insecticidal compounds naturally present in cruciferous plant and perceived as bitter, are good substrates for GSTD2. The X-ray structure of GSTD2 was solved, showing the absence of the classical Ser catalytic residue, conserved in the Delta and Epsilon GSTs. Using molecular dynamics, the interaction of ITC with the GSTD2 three-dimensional structure is analysed and discussed. These findings allow us to consider a biological role for GSTD2 in chemoperception, considering GSTD2 expression in the chemosensory organs and the potential consequences of insect exposure to ITC.
Collapse
Affiliation(s)
- Daniel Gonzalez
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Stéphane Fraichard
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Paul Grassein
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078, Dijon Cedex, France
| | - Patrice Delarue
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078, Dijon Cedex, France
| | - Patrick Senet
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078, Dijon Cedex, France
| | - Adrien Nicolaï
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078, Dijon Cedex, France
| | - Evelyne Chavanne
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Elodie Mucher
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Yves Artur
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Jean-François Ferveur
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Jean-Marie Heydel
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Loïc Briand
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France
| | - Fabrice Neiers
- Centre des Sciences du Goût et de l'Alimentation (CSGA), Université de Bourgogne Franche-Comté, INRA, CNRS, France.
| |
Collapse
|
35
|
Park J, Carlson JR. Physiological responses of the Drosophila labellum to amino acids. J Neurogenet 2018; 32:27-36. [PMID: 29191065 PMCID: PMC6087562 DOI: 10.1080/01677063.2017.1406934] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/15/2017] [Indexed: 10/18/2022]
Abstract
We have systematically studied the physiological responses elicited by amino acids from the principal taste organ of the Drosophila head. Although the detection and coding of sugars and bitter compounds have been examined extensively in this organism, little attention has been paid to the physiology of amino acid taste. We find that one class of sensilla, the S sensilla, yield the strongest responses to amino acids, although these responses were much weaker than the most robust responses to sugar or bitter compounds. S sensilla are heterogeneous in their amino acid responses and amino acids differ in the responses they elicit from individual sensilla. Tryptophan elicited relatively strong responses from S sensilla and these responses were eliminated when bitter-sensing neurons were ablated. Although tryptophan yielded little if any response in a behavioral paradigm, phenylalanine elicited a relatively strong response in the same paradigm and had a different physiological profile, supporting the notion that different amino acids are differentially encoded by the repertoire of taste neurons.
Collapse
Affiliation(s)
- Joori Park
- Dept. of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511
| | - John R. Carlson
- Dept. of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511
| |
Collapse
|
36
|
Nitric oxide contributes to high-salt perception in a blood-sucking insect model. Sci Rep 2017; 7:15551. [PMID: 29138480 PMCID: PMC5686212 DOI: 10.1038/s41598-017-15861-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 11/02/2017] [Indexed: 11/08/2022] Open
Abstract
In all organisms, salts produce either appetitive or aversive responses depending on the concentration. While low-salt concentration in food elicits positive responses to ingest, high-salt triggers aversion. Still the mechanisms involved in this dual behavior have just started to be uncovered in some organisms. In Rhodnius prolixus, using pharmacological and behavioral assays, we demonstrated that upon high-salt detection in food a nitric oxide (NO) dependent cascade is activated. This activation involves a soluble guanylate cyclase (sGC) and the production of cyclic guanosine monophosphate (cGMP). Thus, appetitive responses to low-salt diets turn to aversion whenever this cascade is activated. Conversely, insects feed over aversive high-salt solutions when it is blocked by reducing NO levels or by affecting the sGC activity. The activation of NO/sGC/cGMP cascade commands the avoidance feeding behavior in R. prolixus. Investigations in other insect species should examine the possibility that high-salt aversion is mediated by NO/sSG/cGMP signaling.
Collapse
|
37
|
Uchizono S, Itoh TQ, Kim H, Hamada N, Kwon JY, Tanimura T. Deciphering the Genes for Taste Receptors for Fructose in Drosophila. Mol Cells 2017; 40:731-736. [PMID: 29047261 PMCID: PMC5682250 DOI: 10.14348/molcells.2017.0016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 08/10/2017] [Accepted: 08/20/2017] [Indexed: 11/27/2022] Open
Abstract
Taste sensitivity to sugars plays an essential role in the initiation of feeding behavior. In Drosophila melanogaster, recent studies have identified several gustatory receptor (Gr) genes required for sensing sweet compounds. However, it is as yet undetermined how these GRs function as taste receptors tuned to a wide range of sugars. Among sugars, fructose has been suggested to be detected by a distinct receptor from other sugars. While GR43A has been reported to sense fructose in the brain, it is not expressed in labellar gustatory receptor neurons that show taste response to fructose. In contrast, the Gr64a-Gr64f gene cluster was recently shown to be associated with fructose sensitivity. Here we sought to decipher the genes required for fructose response among Gr64a-Gr64f genes. Unexpectedly, the qPCR analyses for these genes show that labellar expression levels of Gr64d and Gr64e are higher in fructose low-sensitivity flies than in high-sensitivity flies. Moreover, gustatory nerve responses to fructose in labellar sensilla are higher in Gr64d and Gr64f mutant lines than in mutant flies of the other Gr64a-Gr64f genes. These data suggest the possibility that deletion of GR64D or GR64F may indirectly induce enhanced fructose sensitivity in the labellum. Finally, we conclude that response to fructose cannot be explained by a single one of the Gr64a-Gr64f genes.
Collapse
Affiliation(s)
- Shun Uchizono
- Graduate School of Systems Life Sciences, Kyushu University, Motooka, Fukuoka 819-0395,
Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo,
Japan
| | - Taichi Q. Itoh
- Graduate School of Systems Life Sciences, Kyushu University, Motooka, Fukuoka 819-0395,
Japan
- Department of Biology, Faculty of Science, Kyushu University, Motooka, Fukuoka 819-0395,
Japan
| | - Haein Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - Naoki Hamada
- Department of Biology, Faculty of Science, Kyushu University, Motooka, Fukuoka 819-0395,
Japan
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - Teiichi Tanimura
- Graduate School of Systems Life Sciences, Kyushu University, Motooka, Fukuoka 819-0395,
Japan
- Department of Biology, Faculty of Science, Kyushu University, Motooka, Fukuoka 819-0395,
Japan
| |
Collapse
|
38
|
Lee MJ, Sung HY, Jo H, Kim HW, Choi MS, Kwon JY, Kang K. Ionotropic Receptor 76b Is Required for Gustatory Aversion to Excessive Na+ in Drosophila. Mol Cells 2017; 40:787-795. [PMID: 29081083 PMCID: PMC5682255 DOI: 10.14348/molcells.2017.0160] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 08/23/2017] [Indexed: 12/31/2022] Open
Abstract
Avoiding ingestion of excessively salty food is essential for cation homeostasis that underlies various physiological processes in organisms. The molecular and cellular basis of the aversive salt taste, however, remains elusive. Through a behavioral reverse genetic screening, we discover that feeding suppression by Na+-rich food requires Ionotropic Receptor 76b (Ir76b) in Drosophila labellar gustatory receptor neurons (GRNs). Concentrated sodium solutions with various anions caused feeding suppression dependent on Ir76b. Feeding aversion to caffeine and high concentrations of divalent cations and sorbitol was unimpaired in Ir76b-deficient animals, indicating sensory specificity of Ir76b-dependent Na+ detection and the irrelevance of hyperosmolarity-driven mechanosensation to Ir76b-mediated feeding aversion. Ir76b-dependent Na+-sensing GRNs in both L- and s-bristles are required for repulsion as opposed to the previous report where the L-bristle GRNs direct only low-Na+ attraction. Our work extends the physiological implications of Ir76b from low-Na+ attraction to high-Na+ aversion, prompting further investigation of the physiological mechanisms that modulate two competing components of Na+-evoked gustation coded in heterogeneous Ir76b-positive GRNs.
Collapse
Affiliation(s)
- Min Jung Lee
- Samsung Medical Center, Department of Anatomy and Cell Biology, School of Medicine, Sungkyunkwan University, Suwon 16419,
Korea
- Dong-A ST Research Institute, Yongin 17073,
Korea
| | - Ha Yeon Sung
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - HyunJi Jo
- Samsung Medical Center, Department of Anatomy and Cell Biology, School of Medicine, Sungkyunkwan University, Suwon 16419,
Korea
| | - Hyung-Wook Kim
- College of Life Sciences, Sejong University, Seoul 05006,
Korea
| | - Min Sung Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - KyeongJin Kang
- Samsung Medical Center, Department of Anatomy and Cell Biology, School of Medicine, Sungkyunkwan University, Suwon 16419,
Korea
| |
Collapse
|
39
|
Fat storage in Drosophila suzukii is influenced by different dietary sugars in relation to their palatability. PLoS One 2017; 12:e0183173. [PMID: 28817633 PMCID: PMC5560726 DOI: 10.1371/journal.pone.0183173] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/31/2017] [Indexed: 01/14/2023] Open
Abstract
The peripheral sensitivity and palatability of different carbohydrates was evaluated and their nutritional value assessed in adult females of D. suzukii by means of an electrophysiological, behavioural and metabolic approach. The electrophysiological responses were recorded from the labellar "l" type sensilla stimulated with metabolizable mono- and disaccharides (glucose and maltose) and a non-metabolizable sugar (sucralose); the response rating and the palatability to the same sugars, evaluated by recording the proboscis extension reflex (PER), was maltose>glucose>sucralose. The nutritional value of carbohydrates was assessed by means of survival trials and fatty acids profile. Flies fed on a diet containing maltose had a longer lifespan than flies on monosaccharides, while flies fed on a diet containing sucralose had a shorter one. In addition, the ability to store fat seems to be influenced by the different sugars in the diet and is in relationship with their palatability. In fact, data showed a higher synthesis of palmitic and palmitoleic acids, most likely derived from de-novo lipogenesis with glucose as precursor, in flies fed with maltose and glucose than with non-metabolizable sucralose. In conclusion, these results suggest that the ability to select different sugars on the basis of their palatability may favour the storage of energy reserves such as fat by de-novo lipogenesis, determining a longer survival capability during prolonged periods of fasting.
Collapse
|
40
|
Joseph RM, Sun JS, Tam E, Carlson JR. A receptor and neuron that activate a circuit limiting sucrose consumption. eLife 2017; 6. [PMID: 28332980 PMCID: PMC5388533 DOI: 10.7554/elife.24992] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 03/19/2017] [Indexed: 11/23/2022] Open
Abstract
The neural control of sugar consumption is critical for normal metabolism. In contrast to sugar-sensing taste neurons that promote consumption, we identify a taste neuron that limits sucrose consumption in Drosophila. Silencing of the neuron increases sucrose feeding; optogenetic activation decreases it. The feeding inhibition depends on the IR60b receptor, as shown by behavioral analysis and Ca2+ imaging of an IR60b mutant. The IR60b phenotype shows a high degree of chemical specificity when tested with a broad panel of tastants. An automated analysis of feeding behavior in freely moving flies shows that IR60b limits the duration of individual feeding bouts. This receptor and neuron provide the molecular and cellular underpinnings of a new element in the circuit logic of feeding regulation. We propose a dynamic model in which sucrose acts via IR60b to activate a circuit that inhibits feeding and prevents overconsumption. DOI:http://dx.doi.org/10.7554/eLife.24992.001 All animals – from the fruit fly to mammals like humans – must control their dietary intake of nutrients to survive and stay healthy. Taste receptors that sense high-calorie sugars are essential to this process. Typically, when food tastes sweet, it signals that the food contains nutrients and promotes consumption. However, eating too much sugar can be detrimental because the animal wastes time and energy eating food that it does not need, and could eventually lead to obesity and other metabolic diseases. This raised the question: are there any taste receptors that, once they detect sugars, cause animals to eat less? Joseph et al. worked with the fruit fly Drosophila melanogaster and identified one such taste receptor called IR60b. The experiments showed that this taste receptor responds selectively to sucrose (a high-calorie sugar), and that it activates nerve cells that cause fruit flies to eat less food, rather than more. When the receptor was experimentally inactivated, the fruit flies ate for longer and ate too much sucrose. This indicates that the flies need this receptor to control their sugar intake. A next step will be to see if mammals similarly use sweet-sensing taste receptors to limit the amount of food they eat. A better insight into how mammals can control what they eat could provide a deeper understanding of how to tackle major health issues, such as obesity, in humans. DOI:http://dx.doi.org/10.7554/eLife.24992.002
Collapse
Affiliation(s)
- Ryan M Joseph
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
| | - Jennifer S Sun
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
| | - Edric Tam
- Department of Biomedical Engineering, Yale University, New Haven, United States
| | - John R Carlson
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
| |
Collapse
|
41
|
Delventhal R, Menuz K, Joseph R, Park J, Sun JS, Carlson JR. The taste response to ammonia in Drosophila. Sci Rep 2017; 7:43754. [PMID: 28262698 PMCID: PMC5338342 DOI: 10.1038/srep43754] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/26/2017] [Indexed: 01/12/2023] Open
Abstract
Ammonia is both a building block and a breakdown product of amino acids and is found widely in the environment. The odor of ammonia is attractive to many insects, including insect vectors of disease. The olfactory response of Drosophila to ammonia has been studied in some detail, but the taste response has received remarkably little attention. Here, we show that ammonia is a taste cue for Drosophila. Nearly all sensilla of the major taste organ of the Drosophila head house a neuron that responds to neutral solutions of ammonia. Ammonia is toxic at high levels to many organisms, and we find that it has a negative valence in two paradigms of taste behavior, one operating over hours and the other over seconds. Physiological and behavioral responses to ammonia depend at least in part on Gr66a+ bitter-sensing taste neurons, which activate a circuit that deters feeding. The Amt transporter, a critical component of olfactory responses to ammonia, is widely expressed in taste neurons but is not required for taste responses. This work establishes ammonia as an ecologically important taste cue in Drosophila, and shows that it can activate circuits that promote opposite behavioral outcomes via different sensory systems.
Collapse
Affiliation(s)
- R. Delventhal
- Dept. of Molecular, Cellular, and Developmental Biology, Yale University, P.O. Box 208103 New Haven, CT 06520-8103, USA
| | - K. Menuz
- Dept. of Molecular, Cellular, and Developmental Biology, Yale University, P.O. Box 208103 New Haven, CT 06520-8103, USA
| | - R. Joseph
- Dept. of Molecular, Cellular, and Developmental Biology, Yale University, P.O. Box 208103 New Haven, CT 06520-8103, USA
| | - J. Park
- Dept. of Molecular, Cellular, and Developmental Biology, Yale University, P.O. Box 208103 New Haven, CT 06520-8103, USA
| | - J. S. Sun
- Dept. of Molecular, Cellular, and Developmental Biology, Yale University, P.O. Box 208103 New Haven, CT 06520-8103, USA
| | - J. R. Carlson
- Dept. of Molecular, Cellular, and Developmental Biology, Yale University, P.O. Box 208103 New Haven, CT 06520-8103, USA
| |
Collapse
|
42
|
Schwarz O, Bohra AA, Liu X, Reichert H, VijayRaghavan K, Pielage J. Motor control of Drosophila feeding behavior. eLife 2017; 6:e19892. [PMID: 28211791 PMCID: PMC5315463 DOI: 10.7554/elife.19892] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 02/02/2017] [Indexed: 12/01/2022] Open
Abstract
The precise coordination of body parts is essential for survival and behavior of higher organisms. While progress has been made towards the identification of central mechanisms coordinating limb movement, only limited knowledge exists regarding the generation and execution of sequential motor action patterns at the level of individual motoneurons. Here we use Drosophila proboscis extension as a model system for a reaching-like behavior. We first provide a neuroanatomical description of the motoneurons and muscles contributing to proboscis motion. Using genetic targeting in combination with artificial activation and silencing assays we identify the individual motoneurons controlling the five major sequential steps of proboscis extension and retraction. Activity-manipulations during naturally evoked proboscis extension show that orchestration of serial motoneuron activation does not rely on feed-forward mechanisms. Our data support a model in which central command circuits recruit individual motoneurons to generate task-specific proboscis extension sequences.
Collapse
Affiliation(s)
- Olivia Schwarz
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Biozentrum University of Basel, Basel, Switzerland
- Division of Zoology and Neurobiology, Technical University Kaiserslautern, Kaiserslautern, Germany
| | - Ali Asgar Bohra
- National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
| | - Xinyu Liu
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Biozentrum University of Basel, Basel, Switzerland
| | | | | | - Jan Pielage
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Biozentrum University of Basel, Basel, Switzerland
- Division of Zoology and Neurobiology, Technical University Kaiserslautern, Kaiserslautern, Germany
| |
Collapse
|
43
|
Uchizono S, Tanimura T. Genetic Variation in Taste Sensitivity to Sugars in Drosophila melanogaster. Chem Senses 2017; 42:287-294. [DOI: 10.1093/chemse/bjw165] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
44
|
Sparks JT, Dickens JC. Electrophysiological Responses of Gustatory Receptor Neurons on the Labella of the Common Malaria Mosquito, Anopheles quadrimaculatus (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2016; 53:1148-1155. [PMID: 27170738 DOI: 10.1093/jme/tjw073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/20/2016] [Indexed: 06/05/2023]
Abstract
We recorded electrical responses from sensory cells associated with gustatory sensilla on the labella of female Anopheles quadrimaculatus Say to salt, sucrose, quinine (a feeding deterrent), and the insect repellent, N,N-diethyl-3-methylbenzamide (DEET). A salt-sensitive cell responded to increasing concentrations of sodium chloride. A second cell was activated by increasing sucrose concentrations, while quinine, DEET, or a mixture of quinine + DEET elicited spike activity from a third cell, an apparent bitter- or deterrent-sensitive cell. Both quinine and DEET suppressed activity of the sugar-sensitive cell; sucrose suppressed activity of the bitter- or deterrent-sensitive cell. These results demonstrate separate gustatory pathways for a feeding stimulant and aversive contact cues mediated through distinct sensory inputs on the labellum. This sensory appendage may serve as a useful target to disrupt feeding behavior in this and other anopheline species, which transmit diseases like malaria to human populations.
Collapse
Affiliation(s)
- Jackson T Sparks
- United States Department of Agriculture, Agricultural Research Service, Henry A. Wallace Beltsville Agricultural Research Center, Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, MD 20705 (; )
| | - Joseph C Dickens
- United States Department of Agriculture, Agricultural Research Service, Henry A. Wallace Beltsville Agricultural Research Center, Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, MD 20705 (; )
| |
Collapse
|
45
|
Poudel S, Lee Y. Gustatory Receptors Required for Avoiding the Toxic Compound Coumarin in Drosophila melanogaster. Mol Cells 2016; 39:310-5. [PMID: 26912085 PMCID: PMC4844937 DOI: 10.14348/molcells.2016.2250] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/04/2015] [Accepted: 12/17/2015] [Indexed: 11/27/2022] Open
Abstract
Coumarin is a phenolic compound that mainly affects the liver due to its metabolization into a toxic compound. The deterrent and ovicidal activities of coumarin in insect models such as Drosophila melanogaster have been reported. Here we explore the molecular mechanisms by which these insects protect themselves and their eggs from this toxic plant metabolite. Coumarin was fatal to the flies in a dosage-dependent manner. However, coumarin feeding could be inhibited through activation of the aversive gustatory receptor neurons (GRNs), but not the olfactory receptor neurons. Furthermore, three gustatory receptors, GR33a, GR66a, and GR93a, functioned together in coumarin detection by the proboscis. However, GR33a, but not GR66a and GR93a, was required to avoid coumarin during oviposition, with a choice of the same substrates provided as in binary food choice assay. Taken together, these findings suggest that anti-feeding activity and oviposition to avoid coumarin occur via separate mechanisms.
Collapse
Affiliation(s)
- Seeta Poudel
- Department of Bio and Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 136-702,
Korea
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, BK21 PLUS Project, Kookmin University, Seoul 136-702,
Korea
| |
Collapse
|
46
|
Shankar S, Calvert MEK, Yew JY. Measuring Physiological Responses of Drosophila Sensory Neurons to Lipid Pheromones Using Live Calcium Imaging. J Vis Exp 2016. [PMID: 27168110 DOI: 10.3791/53392] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Unlike mammals, insects such as Drosophila have multiple taste organs. The chemosensory neurons on the legs, proboscis, wings and ovipositor of Drosophila express gustatory receptors(1,2), ion channels(3-6), and ionotropic receptors(7) that are involved in the detection of volatile and non-volatile sensory cues. These neurons directly contact tastants such as food, noxious substances and pheromones and therefore influence many complex behaviors such as feeding, egg-laying and mating. Electrode recordings and calcium imaging have been widely used in insects to quantify the neuronal responses evoked by these tastants. However, electrophysiology requires specialized equipment and obtaining measurements from a single taste sensillum can be technically challenging depending on the cell-type, size, and position. In addition, single neuron resolution in Drosophila can be difficult to achieve since taste sensilla house more than one type of chemosensory neuron. The live calcium imaging method described here allows responses of single gustatory neurons in live flies to be measured. This method is especially suitable for imaging neuronal responses to lipid pheromones and other ligand types that have low solubility in water-based solvents.
Collapse
Affiliation(s)
- Shruti Shankar
- Temasek Life Sciences Laboratory; Department of Biological Science, National University of Singapore;
| | - Meredith E K Calvert
- Bioimaging and Biocomputing Facility, Temasek Life Sciences Laboratory; Histology and Light Microscopy Core, Gladstone Institutes
| | - Joanne Y Yew
- Temasek Life Sciences Laboratory; Department of Biological Science, National University of Singapore; Pacific Biosciences Research Center, University of Hawai'i at Mānoa
| |
Collapse
|
47
|
Das G, Lin S, Waddell S. Remembering Components of Food in Drosophila. Front Integr Neurosci 2016; 10:4. [PMID: 26924969 PMCID: PMC4759284 DOI: 10.3389/fnint.2016.00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 01/25/2016] [Indexed: 12/28/2022] Open
Abstract
Remembering features of past feeding experience can refine foraging and food choice. Insects can learn to associate sensory cues with components of food, such as sugars, amino acids, water, salt, alcohol, toxins and pathogens. In the fruit fly Drosophila some food components activate unique subsets of dopaminergic neurons (DANs) that innervate distinct functional zones on the mushroom bodies (MBs). This architecture suggests that the overall dopaminergic neuron population could provide a potential cellular substrate through which the fly might learn to value a variety of food components. In addition, such an arrangement predicts that individual component memories reside in unique locations. DANs are also critical for food memory consolidation and deprivation-state dependent motivational control of the expression of food-relevant memories. Here, we review our current knowledge of how nutrient-specific memories are formed, consolidated and specifically retrieved in insects, with a particular emphasis on Drosophila.
Collapse
Affiliation(s)
- Gaurav Das
- Centre for Neural Circuits and Behaviour, University of OxfordOxford, UK
| | - Suewei Lin
- Centre for Neural Circuits and Behaviour, University of OxfordOxford, UK
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of OxfordOxford, UK
| |
Collapse
|
48
|
Delventhal R, Carlson JR. Bitter taste receptors confer diverse functions to neurons. eLife 2016; 5. [PMID: 26880560 PMCID: PMC4764594 DOI: 10.7554/elife.11181] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/13/2015] [Indexed: 11/17/2022] Open
Abstract
Bitter compounds elicit an aversive response. In Drosophila, bitter-sensitive taste neurons coexpress many members of the Gr family of taste receptors. However, the molecular logic of bitter signaling is unknown. We used an in vivo expression approach to analyze the logic of bitter taste signaling. Ectopic or overexpression of bitter Grs increased endogenous responses or conferred novel responses. Surprisingly, expression of Grs also suppressed many endogenous bitter responses. Conversely, deletion of an endogenous Gr led to novel responses. Expression of individual Grs conferred strikingly different effects in different neurons. The results support a model in which bitter Grs interact, exhibiting competition, inhibition, or activation. The results have broad implications for the problem of how taste systems evolve to detect new environmental dangers. DOI:http://dx.doi.org/10.7554/eLife.11181.001 Insects and other animals use their sense of taste to tell if their food is safe to eat. Plant toxins, for example, often have a bitter flavor that animals can detect and avoid. Fruit flies have many bitter-sensitive nerve cells, but it is not known how the receptors on these nerve cells signal the detection of bitter-flavored compounds. Delventhal and Carlson have now used fruit flies to investigate how taste receptors of the so-called Gustatory receptor family detect bitter flavors. The experimental approach involved genetically modifying four different types of nerve cells that sense bitter compounds so that they produced higher levels of particular taste receptors than normal. Then, the flies were exposed to a range of bitter compounds while the electrical activity of each cell was measured. The analysis involved about 600 combinations of receptors, nerve cells and compounds. In some bitter-sensing nerve cells, increasing the number of taste receptors increased the cell’s responsiveness to bitter compounds. However, in other nerve cells, similar modifications suppressed an existing response or resulted in a new response. Delventhal and Carlson propose that these results suggest the specific response of a bitter-sensing nerve cell depends on the interactions between its different taste receptors. Furthermore, the ability of receptors to compete, inhibit or activate each other in different ways could have implications for evolution. For example, such flexible interactions might allow a taste system to evolve new, enhanced or diminished responses to new food sources and tastes in a changing environment. It now remains to be investigated how such receptor interactions take place at a molecular level. DOI:http://dx.doi.org/10.7554/eLife.11181.002
Collapse
Affiliation(s)
- Rebecca Delventhal
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, United States
| | - John R Carlson
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, United States
| |
Collapse
|
49
|
French A, Ali Agha M, Mitra A, Yanagawa A, Sellier MJ, Marion-Poll F. Drosophila Bitter Taste(s). Front Integr Neurosci 2015; 9:58. [PMID: 26635553 PMCID: PMC4658422 DOI: 10.3389/fnint.2015.00058] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 10/30/2015] [Indexed: 11/13/2022] Open
Abstract
Most animals possess taste receptors neurons detecting potentially noxious compounds. In humans, the ligands which activate these neurons define a sensory space called “bitter”. By extension, this term has been used in animals and insects to define molecules which induce aversive responses. In this review, based on our observations carried out in Drosophila, we examine how bitter compounds are detected and if bitter-sensitive neurons respond only to molecules bitter to humans. Like most animals, flies detect bitter chemicals through a specific population of taste neurons, distinct from those responding to sugars or to other modalities. Activating bitter-sensitive taste neurons induces aversive reactions and inhibits feeding. Bitter molecules also contribute to the suppression of sugar-neuron responses and can lead to a complete inhibition of the responses to sugar at the periphery. Since some bitter molecules activate bitter-sensitive neurons and some inhibit sugar detection, bitter molecules are represented by two sensory spaces which are only partially congruent. In addition to molecules which impact feeding, we recently discovered that the activation of bitter-sensitive neurons also induces grooming. Bitter-sensitive neurons of the wings and of the legs can sense chemicals from the gram negative bacteria, Escherichia coli, thus adding another biological function to these receptors. Bitter-sensitive neurons of the proboscis also respond to the inhibitory pheromone, 7-tricosene. Activating these neurons by bitter molecules in the context of sexual encounter inhibits courting and sexual reproduction, while activating these neurons with 7-tricosene in a feeding context will inhibit feeding. The picture that emerges from these observations is that the taste system is composed of detectors which monitor different “categories” of ligands, which facilitate or inhibit behaviors depending on the context (feeding, sexual reproduction, hygienic behavior), thus considerably extending the initial definition of “bitter” tasting.
Collapse
Affiliation(s)
- Alice French
- Evolution, Génomes, Comportement & Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay Gif-sur-Yvette, France
| | - Moutaz Ali Agha
- Evolution, Génomes, Comportement & Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay Gif-sur-Yvette, France
| | - Aniruddha Mitra
- Evolution, Génomes, Comportement & Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay Gif-sur-Yvette, France
| | - Aya Yanagawa
- Evolution, Génomes, Comportement & Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay Gif-sur-Yvette, France ; Research Institute for Sustainable Humanosphere, Kyoto University Uji City, Japan
| | - Marie-Jeanne Sellier
- Evolution, Génomes, Comportement & Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay Gif-sur-Yvette, France
| | - Frédéric Marion-Poll
- Evolution, Génomes, Comportement & Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay Gif-sur-Yvette, France ; AgroParisTech Paris, France
| |
Collapse
|
50
|
Kessler S, Tiedeken EJ, Simcock KL, Derveau S, Mitchell J, Softley S, Stout JC, Wright GA. Bees prefer foods containing neonicotinoid pesticides. Nature 2015; 521:74-76. [PMID: 25901684 PMCID: PMC4772122 DOI: 10.1038/nature14414] [Citation(s) in RCA: 264] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 03/20/2015] [Indexed: 01/25/2023]
Abstract
The impact of neonicotinoid insecticides on insect pollinators is highly controversial. Sublethal concentrations alter the behaviour of social bees and reduce survival of entire colonies. However, critics argue that the reported negative effects only arise from neonicotinoid concentrations that are greater than those found in the nectar and pollen of pesticide-treated plants. Furthermore, it has been suggested that bees could choose to forage on other available flowers and hence avoid or dilute exposure. Here, using a two-choice feeding assay, we show that the honeybee, Apis mellifera, and the buff-tailed bumblebee, Bombus terrestris, do not avoid nectar-relevant concentrations of three of the most commonly used neonicotinoids, imidacloprid (IMD), thiamethoxam (TMX), and clothianidin (CLO), in food. Moreover, bees of both species prefer to eat more of sucrose solutions laced with IMD or TMX than sucrose alone. Stimulation with IMD, TMX and CLO neither elicited spiking responses from gustatory neurons in the bees' mouthparts, nor inhibited the responses of sucrose-sensitive neurons. Our data indicate that bees cannot taste neonicotinoids and are not repelled by them. Instead, bees preferred solutions containing IMD or TMX, even though the consumption of these pesticides caused them to eat less food overall. This work shows that bees cannot control their exposure to neonicotinoids in food and implies that treating flowering crops with IMD and TMX presents a sizeable hazard to foraging bees.
Collapse
|