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Moreira JM, Itskov PM, Goldschmidt D, Baltazar C, Steck K, Tastekin I, Walker SJ, Ribeiro C. optoPAD, a closed-loop optogenetics system to study the circuit basis of feeding behaviors. eLife 2019; 8:43924. [PMID: 31226244 PMCID: PMC6589098 DOI: 10.7554/elife.43924] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 06/02/2019] [Indexed: 12/19/2022] Open
Abstract
The regulation of feeding plays a key role in determining the fitness of animals through its impact on nutrition. Elucidating the circuit basis of feeding and related behaviors is an important goal in neuroscience. We recently used a system for closed-loop optogenetic manipulation of neurons contingent on the feeding behavior of Drosophila to dissect the impact of a specific subset of taste neurons on yeast feeding. Here, we describe the development and validation of this system, which we term the optoPAD. We use the optoPAD to induce appetitive and aversive effects on feeding by activating or inhibiting gustatory neurons in closed-loop – effectively creating virtual taste realities. The use of optogenetics allowed us to vary the dynamics and probability of stimulation in single flies and assess the impact on feeding behavior quantitatively and with high throughput. These data demonstrate that the optoPAD is a powerful tool to dissect the circuit basis of feeding behavior, allowing the efficient implementation of sophisticated behavioral paradigms to study the mechanistic basis of animals’ adaptation to dynamic environments.
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Affiliation(s)
| | | | | | | | - Kathrin Steck
- Champalimaud Centre for the Unknown, Lisbon, Portugal
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52
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Murgier J, Everaerts C, Farine JP, Ferveur JF. Live yeast in juvenile diet induces species-specific effects on Drosophila adult behaviour and fitness. Sci Rep 2019; 9:8873. [PMID: 31222019 PMCID: PMC6586853 DOI: 10.1038/s41598-019-45140-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 05/24/2019] [Indexed: 02/07/2023] Open
Abstract
The presence and the amount of specific yeasts in the diet of saprophagous insects such as Drosophila can affect their development and fitness. However, the impact of different yeast species in the juvenile diet has rarely been investigated. Here, we measured the behavioural and fitness effects of three live yeasts (Saccharomyces cerevisiae = SC; Hanseniaspora uvarum = HU; Metschnikowia pulcherrima = MP) added to the diet of Drosophila melanogaster larvae. Beside these live yeast species naturally found in natural Drosophila populations or in their food sources, we tested the inactivated "drySC" yeast widely used in Drosophila research laboratories. All flies were transferred to drySC medium immediately after adult emergence, and several life traits and behaviours were measured. These four yeast diets had different effects on pre-imaginal development: HU-rich diet tended to shorten the "egg-to-pupa" period of development while MP-rich diet induced higher larval lethality compared to other diets. Pre- and postzygotic reproduction-related characters (copulatory ability, fecundity, cuticular pheromones) varied according to juvenile diet and sex. Juvenile diet also changed adult food choice preference and longevity. These results indicate that specific yeast species present in natural food sources and ingested by larvae can affect their adult characters crucial for fitness.
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Affiliation(s)
- Juliette Murgier
- Université de Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, AgroSup-UMR 6265 CNRS, UMR 1324 INRA, 6, Bd Gabriel, F-21000, Dijon, France
| | - Claude Everaerts
- Université de Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, AgroSup-UMR 6265 CNRS, UMR 1324 INRA, 6, Bd Gabriel, F-21000, Dijon, France
| | - Jean-Pierre Farine
- Université de Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, AgroSup-UMR 6265 CNRS, UMR 1324 INRA, 6, Bd Gabriel, F-21000, Dijon, France
| | - Jean-François Ferveur
- Université de Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, AgroSup-UMR 6265 CNRS, UMR 1324 INRA, 6, Bd Gabriel, F-21000, Dijon, France.
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53
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Corfas RA, Sharma T, Dickinson MH. Diverse Food-Sensing Neurons Trigger Idiothetic Local Search in Drosophila. Curr Biol 2019; 29:1660-1668.e4. [PMID: 31056390 DOI: 10.1016/j.cub.2019.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/21/2019] [Accepted: 03/06/2019] [Indexed: 01/14/2023]
Abstract
Foraging animals may benefit from remembering the location of a newly discovered food patch while continuing to explore nearby [1, 2]. For example, after encountering a drop of yeast or sugar, hungry flies often perform a local search [3, 4]. That is, rather than remaining on the food or simply walking away, flies execute a series of exploratory excursions during which they repeatedly depart and return to the resource. Fruit flies, Drosophila melanogaster, can perform this food-centered search behavior in the absence of external landmarks, instead relying on internal (idiothetic) cues [5]. This path-integration behavior may represent a deeply conserved navigational capacity in insects [6, 7], but its underlying neural basis remains unknown. Here, we used optogenetic activation to screen candidate cell classes and found that local searches can be initiated by diverse sensory neurons. Optogenetically induced searches resemble those triggered by actual food, are modulated by starvation state, and exhibit key features of path integration. Flies perform tightly centered searches around the fictive food site, even within a constrained maze, and they can return to the fictive food site after long excursions. Together, these results suggest that flies enact local searches in response to a wide variety of food-associated cues and that these sensory pathways may converge upon a common neural system for navigation. Using a virtual reality system, we demonstrate that local searches can be optogenetically induced in tethered flies walking on a spherical treadmill, laying the groundwork for future studies to image the brain during path integration. VIDEO ABSTRACT.
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Affiliation(s)
- Román A Corfas
- Division of Biology & Bioengineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - Tarun Sharma
- Division of Biology & Bioengineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - Michael H Dickinson
- Division of Biology & Bioengineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA.
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54
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Li H, Huang CY, Govorunova EG, Schafer CT, Sineshchekov OA, Wang M, Zheng L, Spudich JL. Crystal structure of a natural light-gated anion channelrhodopsin. eLife 2019; 8:41741. [PMID: 30614787 PMCID: PMC6336409 DOI: 10.7554/elife.41741] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/04/2019] [Indexed: 12/28/2022] Open
Abstract
The anion channelrhodopsin GtACR1 from the alga Guillardia theta is a potent neuron-inhibiting optogenetics tool. Presented here, its X-ray structure at 2.9 Å reveals a tunnel traversing the protein from its extracellular surface to a large cytoplasmic cavity. The tunnel is lined primarily by small polar and aliphatic residues essential for anion conductance. A disulfide-immobilized extracellular cap facilitates channel closing and the ion path is blocked mid-membrane by its photoactive retinylidene chromophore and further by a cytoplasmic side constriction. The structure also reveals a novel photoactive site configuration that maintains the retinylidene Schiff base protonated when the channel is open. These findings suggest a new channelrhodopsin mechanism, in which the Schiff base not only controls gating, but also serves as a direct mediator for anion flux.
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Affiliation(s)
- Hai Li
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center - McGovern Medical School, Houston, United States
| | - Chia-Ying Huang
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
| | - Elena G Govorunova
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center - McGovern Medical School, Houston, United States
| | - Christopher T Schafer
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center - McGovern Medical School, Houston, United States
| | - Oleg A Sineshchekov
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center - McGovern Medical School, Houston, United States
| | - Meitian Wang
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
| | - Lei Zheng
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center - McGovern Medical School, Houston, United States
| | - John L Spudich
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, University of Texas Health Science Center - McGovern Medical School, Houston, United States
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55
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Lushchak O, Strilbytska OM, Yurkevych I, Vaiserman AM, Storey KB. Implications of amino acid sensing and dietary protein to the aging process. Exp Gerontol 2019; 115:69-78. [DOI: 10.1016/j.exger.2018.11.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/05/2018] [Accepted: 11/26/2018] [Indexed: 01/16/2023]
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56
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Tian Y, Wang L. Octopamine mediates protein-seeking behavior in mated female Drosophila. Cell Discov 2018; 4:66. [PMID: 30534416 PMCID: PMC6277437 DOI: 10.1038/s41421-018-0063-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/16/2018] [Accepted: 09/04/2018] [Indexed: 11/17/2022] Open
Affiliation(s)
- Yinjun Tian
- 1Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058 China.,2Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058 China
| | - Liming Wang
- 1Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058 China.,2Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058 China
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57
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Chen YCD, Dahanukar A. DH44 neurons: gut-brain amino acid sensors. Cell Res 2018; 28:1048-1049. [PMID: 30310135 PMCID: PMC6218440 DOI: 10.1038/s41422-018-0101-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 09/25/2018] [Indexed: 11/10/2022] Open
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, Riverside, CA, 92521, USA.
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58
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Chen YCD, Park SJ, Ja WW, Dahanukar A. Using Pox-Neuro ( Poxn) Mutants in Drosophila Gustation Research: A Double-Edged Sword. Front Cell Neurosci 2018; 12:382. [PMID: 30405359 PMCID: PMC6207628 DOI: 10.3389/fncel.2018.00382] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/08/2018] [Indexed: 12/21/2022] Open
Abstract
In Drosophila, Pox-neuro (Poxn) is a member of the Paired box (Pax) gene family that encodes transcription factors with characteristic paired DNA-binding domains. During embryonic development, Poxn is expressed in sensory organ precursor (SOP) cells of poly-innervated external sensory (p-es) organs and is important for specifying p-es organ identity (chemosensory) as opposed to mono-innervated external sensory (m-es) organs (mechanosensory). In Poxn mutants, there is a transformation of chemosensory bristles into mechanosensory bristles. As a result, these mutants have often been considered to be entirely taste-blind, and researchers have used them in this capacity to investigate physiological and behavioral functions that act in a taste-independent manner. However, recent studies show that only external taste bristles are transformed in Poxn mutants whereas all internal pharyngeal taste neurons remain intact, raising concerns about interpretations of experimental results using Poxn mutants as taste-blind flies. In this review, we summarize the value of Poxn mutants in advancing our knowledge of taste-enriched genes and feeding behaviors, and encourage revisiting some of the conclusions about taste-independent nutrient-sensing mechanisms derived from these mutants. Lastly, we highlight that Poxn mutant flies remain a valuable tool for probing the function of the relatively understudied pharyngeal taste neurons in sensing meal properties and regulating feeding behaviors.
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Affiliation(s)
- Yu-Chieh David Chen
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA, United States
| | - Scarlet Jinhong Park
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, United States
| | - William W Ja
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, United States
| | - Anupama Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA, United States.,Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA, United States
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59
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Sánchez-Alcañiz JA, Silbering AF, Croset V, Zappia G, Sivasubramaniam AK, Abuin L, Sahai SY, Münch D, Steck K, Auer TO, Cruchet S, Neagu-Maier GL, Sprecher SG, Ribeiro C, Yapici N, Benton R. An expression atlas of variant ionotropic glutamate receptors identifies a molecular basis of carbonation sensing. Nat Commun 2018; 9:4252. [PMID: 30315166 PMCID: PMC6185939 DOI: 10.1038/s41467-018-06453-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Through analysis of the Drosophila ionotropic receptors (IRs), a family of variant ionotropic glutamate receptors, we reveal that most IRs are expressed in peripheral neuron populations in diverse gustatory organs in larvae and adults. We characterise IR56d, which defines two anatomically-distinct neuron classes in the proboscis: one responds to carbonated solutions and fatty acids while the other represents a subset of sugar- and fatty acid-sensing cells. Mutational analysis indicates that IR56d, together with the broadly-expressed co-receptors IR25a and IR76b, is essential for physiological responses to carbonation and fatty acids, but not sugars. We further demonstrate that carbonation and fatty acids both promote IR56d-dependent attraction of flies, but through different behavioural outputs. Our work provides a toolkit for investigating taste functions of IRs, defines a subset of these receptors required for carbonation sensing, and illustrates how the gustatory system uses combinatorial expression of sensory molecules in distinct neurons to coordinate behaviour. Little is known about the role of variant ionotropic glutamate receptors (IRs) in insect taste. Here the authors characterise the expression pattern of IRs in the Drosophila gustatory system and highlight the role of one receptor, IR56d, in the detection of carbonation
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Affiliation(s)
- Juan Antonio Sánchez-Alcañiz
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland
| | - Ana Florencia Silbering
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland
| | - Vincent Croset
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland.,Centre for Neural Circuits and Behaviour, University of Oxford, Tinsley Building, Mansfield Road, Oxford, OX1 3SR, United Kingdom
| | - Giovanna Zappia
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland
| | - Anantha Krishna Sivasubramaniam
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland
| | - Liliane Abuin
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland
| | - Saumya Yashmohini Sahai
- Department of Neurobiology and Behavior, Cornell University, W153 Mudd Hall, Ithaca, NY, 14853, USA
| | - Daniel Münch
- Champalimaud Centre for the Unknown, Lisbon, 1400-038, Portugal
| | - Kathrin Steck
- Champalimaud Centre for the Unknown, Lisbon, 1400-038, Portugal
| | - Thomas O Auer
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland
| | - Steeve Cruchet
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland
| | - G Larisa Neagu-Maier
- Department of Biology, Institute of Zoology, University of Fribourg, Chemin du Musée 10, Fribourg, CH-1700, Switzerland
| | - Simon G Sprecher
- Department of Biology, Institute of Zoology, University of Fribourg, Chemin du Musée 10, Fribourg, CH-1700, Switzerland
| | - Carlos Ribeiro
- Champalimaud Centre for the Unknown, Lisbon, 1400-038, Portugal
| | - Nilay Yapici
- Department of Neurobiology and Behavior, Cornell University, W153 Mudd Hall, Ithaca, NY, 14853, USA
| | - Richard Benton
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Génopode Building, Lausanne, CH-1015, Switzerland.
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60
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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: 73] [Impact Index Per Article: 12.2] [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.
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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
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61
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Yang Z, Huang R, Fu X, Wang G, Qi W, Mao D, Shi Z, Shen WL, Wang L. A post-ingestive amino acid sensor promotes food consumption in Drosophila. Cell Res 2018; 28:1013-1025. [PMID: 30209352 PMCID: PMC6170445 DOI: 10.1038/s41422-018-0084-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/19/2018] [Accepted: 08/13/2018] [Indexed: 11/29/2022] Open
Abstract
Adequate protein intake is crucial for the survival and well-being of animals. How animals assess prospective protein sources and ensure dietary amino acid intake plays a critical role in protein homeostasis. By using a quantitative feeding assay, we show that three amino acids, L-glutamate (L-Glu), L-alanine (L-Ala) and L-aspartate (L-Asp), but not their D-enantiomers or the other 17 natural L-amino acids combined, rapidly promote food consumption in the fruit fly Drosophila melanogaster. This feeding-promoting effect of dietary amino acids is independent of mating experience and internal nutritional status. In vivo and ex vivo calcium imagings show that six brain neurons expressing diuretic hormone 44 (DH44) can be rapidly and directly activated by these amino acids, suggesting that these neurons are an amino acid sensor. Genetic inactivation of DH44+ neurons abolishes the increase in food consumption induced by dietary amino acids, whereas genetic activation of these neurons is sufficient to promote feeding, suggesting that DH44+ neurons mediate the effect of dietary amino acids to promote food consumption. Single-cell transcriptome analysis and immunostaining reveal that a putative amino acid transporter, CG13248, is enriched in DH44+ neurons. Knocking down CG13248 expression in DH44+ neurons blocks the increase in food consumption and eliminates calcium responses induced by dietary amino acids. Therefore, these data identify DH44+ neuron as a key sensor to detect amino acids and to enhance food intake via a putative transporter CG13248. These results shed critical light on the regulation of protein homeostasis at organismal levels by the nervous system.
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Affiliation(s)
- Zhe Yang
- Life Sciences Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, China.,Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Rui Huang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College, Chongqing University, Chongqing, 400030, China.,Medical School, Chongqing University, 400030, China
| | - Xin Fu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gaohang Wang
- Life Sciences Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, China.,Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Wei Qi
- Life Sciences Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, China.,Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Decai Mao
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, 100084, China
| | - Zhaomei Shi
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Wei L Shen
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Liming Wang
- Life Sciences Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, China. .,Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, 310058, Zhejiang, China.
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62
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Gomez-Diaz C, Martin F, Garcia-Fernandez JM, Alcorta E. The Two Main Olfactory Receptor Families in Drosophila, ORs and IRs: A Comparative Approach. Front Cell Neurosci 2018; 12:253. [PMID: 30214396 PMCID: PMC6125307 DOI: 10.3389/fncel.2018.00253] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 07/23/2018] [Indexed: 12/20/2022] Open
Abstract
Most insect species rely on the detection of olfactory cues for critical behaviors for the survival of the species, e.g., finding food, suitable mates and appropriate egg-laying sites. Although insects show a diverse array of molecular receptors dedicated to the detection of sensory cues, two main types of molecular receptors have been described as responsible for olfactory reception in Drosophila, the odorant receptors (ORs) and the ionotropic receptors (IRs). Although both receptor families share the role of being the first chemosensors in the insect olfactory system, they show distinct evolutionary origins and several distinct structural and functional characteristics. While ORs are seven-transmembrane-domain receptor proteins, IRs are related to the ionotropic glutamate receptor (iGluR) family. Both types of receptors are expressed on the olfactory sensory neurons (OSNs) of the main olfactory organ, the antenna, but they are housed in different types of sensilla, IRs in coeloconic sensilla and ORs in basiconic and trichoid sensilla. More importantly, from the functional point of view, they display different odorant specificity profiles. Research advances in the last decade have improved our understanding of the molecular basis, evolution and functional roles of these two families, but there are still controversies and unsolved key questions that remain to be answered. Here, we present an updated review on the advances of the genetic basis, evolution, structure, functional response and regulation of both types of chemosensory receptors. We use a comparative approach to highlight the similarities and differences among them. Moreover, we will discuss major open questions in the field of olfactory reception in insects. A comprehensive analysis of the structural and functional convergence and divergence of both types of receptors will help in elucidating the molecular basis of the function and regulation of chemoreception in insects.
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Affiliation(s)
- Carolina Gomez-Diaz
- Department of Functional Biology, Faculty of Medicine, University of Oviedo, Oviedo, Spain
| | - Fernando Martin
- Department of Functional Biology, Faculty of Medicine, University of Oviedo, Oviedo, Spain
| | | | - Esther Alcorta
- Department of Functional Biology, Faculty of Medicine, University of Oviedo, Oviedo, Spain
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Govorunova EG, Sineshchekov OA, Hemmati R, Janz R, Morelle O, Melkonian M, Wong GKS, Spudich JL. Extending the Time Domain of Neuronal Silencing with Cryptophyte Anion Channelrhodopsins. eNeuro 2018; 5:ENEURO.0174-18.2018. [PMID: 30027111 PMCID: PMC6051594 DOI: 10.1523/eneuro.0174-18.2018] [Citation(s) in RCA: 20] [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: 05/02/2018] [Revised: 06/19/2018] [Accepted: 06/19/2018] [Indexed: 12/31/2022] Open
Abstract
Optogenetic inhibition of specific neuronal types in the brain enables analysis of neural circuitry and is promising for the treatment of a number of neurological disorders. Anion channelrhodopsins (ACRs) from the cryptophyte alga Guillardia theta generate larger photocurrents than other available inhibitory optogenetic tools, but more rapid channels are needed for temporally precise inhibition, such as single-spike suppression, of high-frequency firing neurons. Faster ACRs have been reported, but their potential advantages for time-resolved inhibitory optogenetics have not so far been verified in neurons. We report RapACR, nicknamed so for "rapid," an ACR from Rhodomonas salina, that exhibits channel half-closing times below 10 ms and achieves equivalent inhibition at 50-fold lower light intensity in lentivirally transduced cultured mouse hippocampal neurons as the second-generation engineered Cl--conducting channelrhodopsin iC++. The upper limit of the time resolution of neuronal silencing with RapACR determined by measuring the dependence of spiking recovery after photoinhibition on the light intensity was calculated to be 100 Hz, whereas that with the faster of the two G. theta ACRs was 13 Hz. Further acceleration of RapACR channel kinetics was achieved by site-directed mutagenesis of a single residue in transmembrane helix 3 (Thr111 to Cys). We also show that mutation of another ACR (Cys to Ala at the same position) with a greatly extended lifetime of the channel open state acts as a bistable photochromic tool in mammalian neurons. These molecules extend the time domain of optogenetic neuronal silencing while retaining the high light sensitivity of Guillardia ACRs.
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Affiliation(s)
- Elena G. Govorunova
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX 77030
| | - Oleg A. Sineshchekov
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX 77030
| | - Raheleh Hemmati
- Department of Neurobiology and Anatomy, The University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX 77030
| | - Roger Janz
- Department of Neurobiology and Anatomy, The University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX 77030
| | - Olivier Morelle
- Institute of Botany, Cologne Biocenter, University of Cologne, Cologne D-50674, Germany
| | - Michael Melkonian
- Institute of Botany, Cologne Biocenter, University of Cologne, Cologne D-50674, Germany
| | - Gane K.-S. Wong
- Departments of Biological Sciences and of Medicine, University of Alberta, Edmonton, AB T6G 2E1, Canada
- Beijing Genomics Institute-Shenzhen, Shenzhen 518083, China
| | - John L. Spudich
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX 77030
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