1
|
Sun J, Zhang W, Cui Z, Pan Y, Smagghe G, Zhang L, Wickham JD, Sun J, Mang D. HcGr76 responds to fructose and chlorogenic acid and is involved in regulation of peptide expression in the midgut of Hyphantria cunea larvae. PEST MANAGEMENT SCIENCE 2024; 80:5672-5683. [PMID: 38982883 DOI: 10.1002/ps.8285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/31/2024] [Accepted: 06/20/2024] [Indexed: 07/11/2024]
Abstract
BACKGROUND Sensing dietary components in the gut is important to ensure an appropriate hormonal response and metabolic regulation after food intake. The fall webworm, Hyphantria cunea, is a major invasive pest in China and has led to significant economic losses and ecosystem disruption. The larvae's broad host range and voracious appetite for leaves make H. cunea a primary cause of serious damage to both forests and crops. To date, however, the gustatory receptors (Grs) of H. cunea and their regulatory function remain largely unknown. RESULTS We identified the fall webworm gustatory receptor HcGr76 as a fructose and chlorogenic acid receptor using Ca2+ imaging and determination of intracellular Ca2+ concentration by a microplate reader. Moreover, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis revealed that HcGr76 is highly expressed in the anterior and middle midgut. Knockdown of HcGr76 caused a significant reduction in the expression of neuropeptide F 1 (NPF1) and CCHamide-2, and led to a decrease in carbohydrate and lipid levels in the hemolymph. CONCLUSION Our studies provide circumstantial evidence that HcGr76 expressed in the midgut is involved in sensing dietary components, and regulates the expression of relevant peptide hormones to alter metabolism in H. cunea larvae, thus providing a promising molecular target for the development of new insect-specific control products. © 2024 Society of Chemical Industry.
Collapse
Affiliation(s)
- Jing Sun
- College of Life Science, Hebei University, Baoding, China
| | - Wenjing Zhang
- College of Life Science, Hebei University, Baoding, China
| | - Zhebo Cui
- College of Life Science, Hebei University, Baoding, China
| | - Yifan Pan
- College of Life Science, Hebei University, Baoding, China
- Hebei Basic Science Center for Biotic Interaction, Hebei University, Baoding, China
| | - Guy Smagghe
- Institute of Entomology and Special Key Laboratory for Development and Utilization of Insect Resources of Guizhou, Guizhou University, Guiyang, China
- Cellular and Molecular Life Sciences, Department of Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Department of Plants and Crops, Ghent University, Ghent, Belgium
| | - Longwa Zhang
- Anhui Provincial Key Laboratory of Microbial Control, Engineering Research Center of Fungal Biotechnology, Ministry of Education, School of Forestry & Landscape Architecture, Anhui Agricultural University, Hefei, China
| | - Jacob D Wickham
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Jianghua Sun
- College of Life Science, Hebei University, Baoding, China
- Hebei Basic Science Center for Biotic Interaction, Hebei University, Baoding, China
| | - Dingze Mang
- College of Life Science, Hebei University, Baoding, China
- Hebei Basic Science Center for Biotic Interaction, Hebei University, Baoding, China
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
| |
Collapse
|
2
|
Zhang SS, Wang PC, Ning C, Yang K, Li GC, Cao LL, Huang LQ, Wang CZ. The larva and adult of Helicoverpa armigera use differential gustatory receptors to sense sucrose. eLife 2024; 12:RP91711. [PMID: 38814697 PMCID: PMC11139476 DOI: 10.7554/elife.91711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024] Open
Abstract
Almost all herbivorous insects feed on plants and use sucrose as a feeding stimulant, but the molecular basis of their sucrose reception remains unclear. Helicoverpa armigera as a notorious crop pest worldwide mainly feeds on reproductive organs of many plant species in the larval stage, and its adult draws nectar. In this study, we determined that the sucrose sensory neurons located in the contact chemosensilla on larval maxillary galea were 100-1000 times more sensitive to sucrose than those on adult antennae, tarsi, and proboscis. Using the Xenopus expression system, we discovered that Gr10 highly expressed in the larval sensilla was specifically tuned to sucrose, while Gr6 highly expressed in the adult sensilla responded to fucose, sucrose and fructose. Moreover, using CRISPR/Cas9, we revealed that Gr10 was mainly used by larvae to detect lower sucrose, while Gr6 was primarily used by adults to detect higher sucrose and other saccharides, which results in differences in selectivity and sensitivity between larval and adult sugar sensory neurons. Our results demonstrate the sugar receptors in this moth are evolved to adapt toward the larval and adult foods with different types and amounts of sugar, and fill in a gap in sweet taste of animals.
Collapse
Affiliation(s)
- Shuai-Shuai Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of SciencesBeijingChina
| | - Pei-Chao Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of SciencesBeijingChina
| | - Chao Ning
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of SciencesBeijingChina
| | - Ke Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of SciencesBeijingChina
| | - Guo-Cheng Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of SciencesBeijingChina
| | - Lin-Lin Cao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of SciencesBeijingChina
| | - Ling-Qiao Huang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
| | - Chen-Zhu Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of SciencesBeijingChina
| |
Collapse
|
3
|
Shi J, He L, Du J, Wang CZ, Zhao Z. Mechanism of foraging selections regulated by gustatory receptor 43a in Ostrinia furnacalis larvae. PEST MANAGEMENT SCIENCE 2024; 80:978-987. [PMID: 37822037 DOI: 10.1002/ps.7828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 09/28/2023] [Accepted: 10/12/2023] [Indexed: 10/13/2023]
Abstract
BACKGROUND Omnivores, including humans, have an inborn tendency to avoid risky or non-nutritious foods. However, relatively little is known about how animals perceive and discriminate nutritious foods from risky substances. In this study, we explored the mechanism of feeding selection in Ostrinia furnacalis larvae, one of the most destructive pests to the maize crop. RESULTS We identified a gustatory receptor, Gr43a, for feeding regulation in larvae of Ostrinia furnacalis, which highly expresses in the mouthparts of the first- (the period of just hatching out from eggs) and fifth-instar larvae (the period of gluttony). The Gr43a regulates foraging plasticity by discriminating sorbitol, a nonsweet nutritious substance, and sucralose, a sweet non-nutritious substance through the labra of mouthparts, while it differentiates fructose/sucrose and sucralose via the sensilla styloconica of mouthparts. Specially, Gr43a responds to fructose and sucrose via the medial and lateral sensilla styloconica in O. furnacalis, respectively. Furthermore, Gr43a is negatively regulated by the neuropeptide F system, a homologous mammalian neuropeptide Y system. CONCLUSION This study reveals a smart feeding strategy for animals to meet both nutritional needs and sweet gratification, and offers an insight into complex feeding selections dependent on food resources in the surrounding environment. © 2023 Society of Chemical Industry.
Collapse
Affiliation(s)
- Jian Shi
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Lei He
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Juan Du
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Chen-Zhu Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhangwu Zhao
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| |
Collapse
|
4
|
Ma D, Hu M, Yang X, Liu Q, Ye F, Cai W, Wang Y, Xu X, Chang S, Wang R, Yang W, Ye S, Su N, Fan M, Xu H, Guo J. Structural basis for sugar perception by Drosophila gustatory receptors. Science 2024; 383:eadj2609. [PMID: 38305684 DOI: 10.1126/science.adj2609] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 01/17/2024] [Indexed: 02/03/2024]
Abstract
Insects rely on a family of seven transmembrane proteins called gustatory receptors (GRs) to encode different taste modalities, such as sweet and bitter. We report structures of Drosophila sweet taste receptors GR43a and GR64a in the apo and sugar-bound states. Both GRs form tetrameric sugar-gated cation channels composed of one central pore domain (PD) and four peripheral ligand-binding domains (LBDs). Whereas GR43a is specifically activated by the monosaccharide fructose that binds to a narrow pocket in LBDs, disaccharides sucrose and maltose selectively activate GR64a by binding to a larger and flatter pocket in LBDs. Sugar binding to LBDs induces local conformational changes, which are subsequently transferred to the PD to cause channel opening. Our studies reveal a structural basis for sugar recognition and activation of GRs.
Collapse
Affiliation(s)
- Demin Ma
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Nanhu Brain-Computer Interface Institute, Hangzhou 311100, China
| | - Meiqin Hu
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310058, China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou 311121, China
| | - Xiaotong Yang
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310058, China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou 311121, China
| | - Qiang Liu
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310058, China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou 311121, China
| | - Fan Ye
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Nanhu Brain-Computer Interface Institute, Hangzhou 311100, China
| | - Weijie Cai
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310058, China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou 311121, China
| | - Yong Wang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ximing Xu
- Marine Biomedical Institute of Qingdao, School of Pharmacy and Medicine, Ocean University of China, Qingdao, Shandong 266100, China
| | - Shenghai Chang
- Center of Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Ruiying Wang
- CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Wei Yang
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Sheng Ye
- Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Nannan Su
- International Institutes of Medicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang 322000, China
| | - Minrui Fan
- CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Haoxing Xu
- Department of Neurology and Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310058, China
- New Cornerstone Science Laboratory, Liangzhu Laboratory and School of Basic Medical Sciences, Zhejiang University, Hangzhou 311121, China
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jiangtao Guo
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Nanhu Brain-Computer Interface Institute, Hangzhou 311100, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
- State Key Laboratory of Plant Environmental Resilience, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
- Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China
| |
Collapse
|
5
|
Zhang G, Cao S, Wang H, Cao Z, Wei B, Niu C. Identification of a new gustatory receptor BminGR59b tuned to host wax in a specialist, Bactrocera minax (Diptera: Tephritidae). Int J Biol Macromol 2023; 253:127180. [PMID: 37838119 DOI: 10.1016/j.ijbiomac.2023.127180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/17/2023] [Accepted: 09/24/2023] [Indexed: 10/16/2023]
Abstract
Host location plays a pivotal role in the coevolution between insects and plants, particularly for specialist insect herbivores with a limited host range. However, how specialists precisely select the appropriate site for oviposition through gustatory system remains elusive. In this study, we investigated the effects of the gustatory system on the host plant selection of a devastating pest in Citrus spp., Bactrocera minax, by conducting behavioral assays. Through genomic and transcriptomic data analysis as well as RNAi technology, we identified a novel gustatory receptor, BminGR59b, highly expressed in the forelegs of female B. minax, which played a critical role in host plant selection before oviposition decision. Additionally, our results encompassing heterologous expression in Sf9 cells and oviposition behavior assay revealed that n-eicosane is the ligand for BminGR59b. Finally, employing the dual luciferase reporter system alongside yeast one-hybrid techniques and RNAi, we verified that the transcription factor BminCEBP regulated the up-regulation of BminGR59b in sexually matured adults. These findings offer new insights into the close-range host fruit recognition and selection for oviposition in a specialist tephritid fruit fly B. minax, which also sheds light on the transcriptional regulation mechanisms underlying the gustatory-mediated oviposition in specialist herbivores for the first time.
Collapse
Affiliation(s)
- Guijian Zhang
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Shuai Cao
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Haoran Wang
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Zhen Cao
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Bingbing Wei
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Changying Niu
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
| |
Collapse
|
6
|
Ahn JE, Amrein H. Opposing chemosensory functions of closely related gustatory receptors. eLife 2023; 12:RP89795. [PMID: 38060294 PMCID: PMC10703443 DOI: 10.7554/elife.89795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023] Open
Abstract
In the fruit fly Drosophila melanogaster, gustatory sensory neurons express taste receptors that are tuned to distinct groups of chemicals, thereby activating neural ensembles that elicit either feeding or avoidance behavior. Members of a family of ligand -gated receptor channels, the Gustatory receptors (Grs), play a central role in these behaviors. In general, closely related, evolutionarily conserved Gr proteins are co-expressed in the same type of taste neurons, tuned to chemically related compounds, and therefore triggering the same behavioral response. Here, we report that members of the Gr28 subfamily are expressed in largely non-overlapping sets of taste neurons in Drosophila larvae, detect chemicals of different valence, and trigger opposing feeding behaviors. We determined the intrinsic properties of Gr28 neurons by expressing the mammalian Vanilloid Receptor 1 (VR1), which is activated by capsaicin, a chemical to which wild-type Drosophila larvae do not respond. When VR1 is expressed in Gr28a neurons, larvae become attracted to capsaicin, consistent with reports showing that Gr28a itself encodes a receptor for nutritious RNA. In contrast, expression of VR1 in two pairs of Gr28b.c neurons triggers avoidance to capsaicin. Moreover, neuronal inactivation experiments show that the Gr28b.c neurons are necessary for avoidance of several bitter compounds. Lastly, behavioral experiments of Gr28 deficient larvae and live Ca2+ imaging studies of Gr28b.c neurons revealed that denatonium benzoate, a synthetic bitter compound that shares structural similarities with natural bitter chemicals, is a ligand for a receptor complex containing a Gr28b.c or Gr28b.a subunit. Thus, the Gr28 proteins, which have been evolutionarily conserved over 260 million years in insects, represent the first taste receptor subfamily in which specific members mediate behavior with opposite valence.
Collapse
Affiliation(s)
- Ji-Eun Ahn
- Department of Cell Biology and Genetics, School of Medicine, Texas A&M UniversityBryanUnited States
| | - Hubert Amrein
- Department of Cell Biology and Genetics, School of Medicine, Texas A&M UniversityBryanUnited States
| |
Collapse
|
7
|
Ahn JE, Amrein H. Opposing chemosensory functions of closely related gustatory receptors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.20.545761. [PMID: 37905057 PMCID: PMC10614748 DOI: 10.1101/2023.06.20.545761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Most animals have functionally distinct populations of taste cells, expressing receptors that are tuned to compounds of different valence. This organizational feature allows for discrimination between chemicals associated with specific taste modalities and facilitates differentiating between unadulterated foods and foods contaminated with toxic substances. In the fruit fly D. melanogaster , primary sensory neurons express taste receptors that are tuned to distinct groups of chemicals, thereby activating neural ensembles that elicit either feeding or avoidance behavior. Members of a family of ligand gated receptor channels, the Gustatory receptors (Grs), play a central role in these behaviors. In general, closely related, evolutionarily conserved Gr proteins are co-expressed in the same type of taste neurons, tuned to chemically related compounds, and therefore triggering the same behavioral response. Here, we report that members of the Gr28 subfamily are expressed in largely non-overlapping sets of taste neurons in Drosophila larvae, detect chemicals of different valence and trigger opposing feeding behaviors. We determined the intrinsic properties of Gr28 neurons by expressing the mammalian Vanilloid Receptor (VR1), which is activated by capsaicin, a chemical to which wildtype Drosophila larvae do not respond. When VR1 is expressed in Gr28a neurons, larvae become attracted to capsaicin, consistent with reports showing that Gr28a itself encodes a receptor for nutritious RNA. In contrast, expression of VR1 in two pairs of Gr28b.c neurons triggers avoidance to capsaicin. Moreover, neuronal inactivation experiments show that the Gr28b.c neurons are necessary for avoidance of several bitter compounds. Lastly, behavioral experiments of Gr28 deficient larvae and live Ca 2+ imaging studies of Gr28b.c neurons revealed that denatonium benzoate, a synthetic bitter compound that shares structural similarities with natural bitter chemicals, is a ligand for a receptor complex containing a Gr28b.c or Gr28b.a subunit. Thus, the Gr28 proteins, which have been evolutionarily conserved over 260 million years in insects, represent the first taste receptor subfamily in which specific members mediate behavior with opposite valence.
Collapse
|
8
|
Lee SG, Sun D, Miao H, Wu Z, Kang C, Saad B, Nguyen KNH, Guerra-Phalen A, Bui D, Abbas AH, Trinh B, Malik A, Zeghal M, Auge AC, Islam ME, Wong K, Stern T, Lebedev E, Sherratt TN, Kim WJ. Taste and pheromonal inputs govern the regulation of time investment for mating by sexual experience in male Drosophila melanogaster. PLoS Genet 2023; 19:e1010753. [PMID: 37216404 DOI: 10.1371/journal.pgen.1010753] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 04/20/2023] [Indexed: 05/24/2023] Open
Abstract
Males have finite resources to spend on reproduction. Thus, males rely on a 'time investment strategy' to maximize their reproductive success. For example, male Drosophila melanogaster extends their mating duration when surrounded by conditions enriched with rivals. Here we report a different form of behavioral plasticity whereby male fruit flies exhibit a shortened duration of mating when they are sexually experienced; we refer to this plasticity as 'shorter-mating-duration (SMD)'. SMD is a plastic behavior and requires sexually dimorphic taste neurons. We identified several neurons in the male foreleg and midleg that express specific sugar and pheromone receptors. Using a cost-benefit model and behavioral experiments, we further show that SMD behavior exhibits adaptive behavioral plasticity in male flies. Thus, our study delineates the molecular and cellular basis of the sensory inputs required for SMD; this represents a plastic interval timing behavior that could serve as a model system to study how multisensory inputs converge to modify interval timing behavior for improved adaptation.
Collapse
Affiliation(s)
- Seung Gee Lee
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Dongyu Sun
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China
| | - Hongyu Miao
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China
| | - Zekun Wu
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China
| | - Changku Kang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Baraa Saad
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | | | - Adrian Guerra-Phalen
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Dorothy Bui
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Al-Hassan Abbas
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Brian Trinh
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Ashvent Malik
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Mahdi Zeghal
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Anne-Christine Auge
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Md Ehteshamul Islam
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Kyle Wong
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Tiffany Stern
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Elizabeth Lebedev
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | | | - Woo Jae Kim
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
- The HIT Center for Life Sciences, Harbin Institute of Technology, Harbin, China
| |
Collapse
|
9
|
Aidlin Harari O, Dekel A, Wintraube D, Vainer Y, Mozes-Koch R, Yakir E, Malka O, Morin S, Bohbot JD. A sucrose-specific receptor in Bemisia tabaci and its putative role in phloem feeding. iScience 2023; 26:106752. [PMID: 37234092 PMCID: PMC10206433 DOI: 10.1016/j.isci.2023.106752] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/22/2022] [Accepted: 04/22/2023] [Indexed: 05/27/2023] Open
Abstract
In insects, specialized feeding on the phloem sap (containing mainly the sugar sucrose) has evolved only in some hemipteran lineages. This feeding behavior requires an ability to locate feeding sites buried deeply within the plant tissue. To determine the molecular mechanism involved, we hypothesized that the phloem-feeding whitefly Bemisia tabaci relies on gustatory receptor (GR)-mediated sugar sensing. We first conducted choice assays, which indicated that B. tabaci adults consistently choose diets containing higher sucrose concentrations. Next, we identified four GR genes in the B. tabaci genome. One of them, BtabGR1, displayed significant sucrose specificity when expressed in Xenopus oocytes. Silencing of BtabGR1 significantly interfered with the ability of B. tabaci adults to discriminate between non-phloem and phloem concentrations of sucrose. These findings suggest that in phloem feeders, sugar sensing by sugar receptors might allow tracking an increasing gradient of sucrose concentrations in the leaf, leading eventually to the location of the feeding site.
Collapse
Affiliation(s)
- Ofer Aidlin Harari
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Amir Dekel
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Dor Wintraube
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Yuri Vainer
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Rita Mozes-Koch
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Esther Yakir
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Osnat Malka
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Shai Morin
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| | - Jonathan D. Bohbot
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot 76100, Israel
| |
Collapse
|
10
|
Mang D, Toyama T, Yamagishi T, Sun J, Purba ER, Endo H, Matthews MM, Ito K, Nagata S, Sato R. Dietary compounds activate an insect gustatory receptor on enteroendocrine cells to elicit myosuppressin secretion. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 155:103927. [PMID: 36871864 DOI: 10.1016/j.ibmb.2023.103927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 03/01/2023] [Accepted: 03/01/2023] [Indexed: 05/10/2023]
Abstract
Sensing of midgut internal contents is important for ensuring appropriate hormonal response and digestion following the ingestion of dietary components. Studies in mammals have demonstrated that taste receptors (TRs), a subgroup of G protein-coupled receptors (GPCRs), are expressed in gut enteroendocrine cells (EECs) to sense dietary compounds and regulate the production and/or secretion of peptide hormones. Although progress has been made in identifying expression patterns of gustatory receptors (GRs) in gut EECs, it is currently unknown whether these receptors, which act as ligand-gated ion channels, serve similar functions as mammalian GPCR TRs to elicit hormone production and/or secretion. A Bombyx mori Gr, BmGr6, has been demonstrated to express in cells by oral sensory organs, midgut and nervous system; and to sense isoquercitrin and chlorogenic acid, which are non-nutritional secondary metabolites of host mulberry. Here, we show that BmGr6 co-expresses with Bommo-myosuppressin (BMS) in midgut EECs, responds to dietary compounds and is involved in regulation of BMS secretion. The presence of dietary compounds in midgut lumen after food intake resulted in an increase of BMS secretions in hemolymph of both wild-type and BmGr9 knockout larvae, but BMS secretions in BmGr6 knockout larvae decreased relative to wild-type. In addition, loss of BmGr6 led to a significant decrease in weight gain, excrement, hemolymph carbohydrates levels and hemolymph lipid levels. Interestingly, although BMS is produced in both midgut EECs and brain neurosecretory cells (NSCs), BMS levels in tissue extracts suggested that the increase in hemolymph BMS during feeding conditions is primarily due to secretion from midgut EECs. Our studies indicate that BmGr6 expressed in midgut EECs responds to the presence of dietary compounds in the lumen by eliciting BMS secretion in B. mori larvae.
Collapse
Affiliation(s)
- Dingze Mang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China; Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan.
| | - Tomoko Toyama
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan
| | - Takayuki Yamagishi
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan
| | - Jing Sun
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, 071002, China
| | - Endang R Purba
- Structural Cellular Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Haruka Endo
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan
| | - Melissa M Matthews
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Katsuhiko Ito
- Department of Science of Biological Production, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Shinji Nagata
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Ryoichi Sato
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo, 184-8588, Japan.
| |
Collapse
|
11
|
Fujii S, Ahn JE, Jagge C, Shetty V, Janes C, Mohanty A, Slotman M, Adelman ZN, Amrein H. RNA Taste Is Conserved in Dipteran Insects. J Nutr 2023; 153:1636-1645. [PMID: 36907444 DOI: 10.1016/j.tjnut.2023.03.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 03/06/2023] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
BACKGROUND Ribonucleosides and RNA are an underappreciated nutrient group essential during Drosophila larval development and growth. Detection of these nutrients requires at least one of the 6 closely related taste receptors encoded by the Gr28 genes, one of the most conserved insect taste receptor subfamilies. OBJECTIVES We investigated whether blow fly larvae and mosquito larvae, which shared the last ancestor with Drosophila about 65-260 million years ago, respectively, can taste RNA and ribose. We also tested whether the Gr28 homologous genes of the mosquitoes Aedes aegypti and Anopheles gambiae can sense these nutrients when expressed in transgenic Drosophila larvae. METHODS Taste preference in blow flies was examined by adapting a 2-choice preference assay that has been well-established for Drosophila larvae. For the mosquito Aedes aegypti larvae, we developed a new 2-choice preference assay that accommodates the aquatic environment of these insects. Finally, we identified Gr28 homologs in these species and expressed them in Drosophila melanogaster to determine their potential function as RNA receptors. RESULTS Larvae of the blow fly Cochliomyia macellaria and Lucilia cuprina are strongly attracted to RNA (0.5 mg/mL) in the 2-choice feeding assays (P < 0.05). Similarly, the mosquito Aedes aegypti larvae showed a strong preference for RNA (2.5 mg/mL) in an aquatic 2-choice feeding assay. Moreover, when Gr28 homologs of Aedes or Anopheles mosquitoes are expressed in appetitive taste neurons of Drosophila melanogaster larvae lacking their Gr28 genes, preference for RNA (0.5 mg/mL) and ribose (0.1 M) is rescued (P < 0.05). CONCLUSIONS The appetitive taste for RNA and ribonucleosides in insects emerged about 260 million years ago, the time mosquitoes and fruit flies diverged from their last common ancestor. Like sugar receptors, receptors for RNA have been highly conserved during insect evolution, suggesting that RNA is a critical nutrient for fast-growing insect larvae. J NUTR 2023;xx:xx-xx.
Collapse
Affiliation(s)
- Shinsuke Fujii
- Department of Cell Biology and Genetics, School of Medicine, Texas A&M University, Bryan, TX, United States
| | - Ji-Eun Ahn
- Department of Cell Biology and Genetics, School of Medicine, Texas A&M University, Bryan, TX, United States
| | - Christopher Jagge
- Department of Cell Biology and Genetics, School of Medicine, Texas A&M University, Bryan, TX, United States
| | - Vinaya Shetty
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, United States
| | - Christopher Janes
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, United States
| | - Avha Mohanty
- Department of Cell Biology and Genetics, School of Medicine, Texas A&M University, Bryan, TX, United States
| | - Michel Slotman
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, United States
| | - Zach N Adelman
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, United States
| | - Hubert Amrein
- Department of Cell Biology and Genetics, School of Medicine, Texas A&M University, Bryan, TX, United States.
| |
Collapse
|
12
|
Walker WB, Mori BA, Cattaneo AM, Gonzalez F, Witzgall P, Becher PG. Comparative transcriptomic assessment of the chemosensory receptor repertoire of Drosophila suzukii adult and larval olfactory organs. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2023; 45:101049. [PMID: 36528931 DOI: 10.1016/j.cbd.2022.101049] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/10/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Abstract
The spotted wing Drosophila, Drosophila suzukii, has emerged within the past decade as an invasive species on a global scale, and is one of the most economically important pests in fruit and berry production in Europe and North America. Insect ecology, to a strong degree, depends on the chemosensory modalities of smell and taste. Extensive research on the sensory receptors of the olfactory and gustatory systems in Drosophila melanogaster provide an excellent frame of reference to better understand the fundamentals of the chemosensory systems of D. suzukii. This knowledge may enhance the development of semiochemicals for sustainable management of D. suzukii, which is urgently needed. Here, using a transcriptomic approach we report the chemosensory receptor expression profiles in D. suzukii female and male antennae, and for the first time, in larval heads including the dorsal organ that houses larval olfactory sensory neurons. In D. suzukii adults, we generally observed a lack of sexually dimorphic expression levels in male and female antennae. While there was generally conservation of antennal expression of odorant and ionotropic receptor orthologues for D. melanogaster and D. suzukii, gustatory receptors showed more distinct species-specific profiles. In larval head tissues, for all three receptor gene families, there was also a greater degree of species-specific gene expression patterns. Analysis of chemosensory receptor repertoires in the pest species, D. suzukii relative to those of the genetic model D. melanogaster enables comparative studies of the chemosensory, physiology, and ecology of D. suzukii.
Collapse
Affiliation(s)
- William B Walker
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden; USDA-ARS Temperate Tree Fruit and Vegetable Research Unit, 5230 Konnowac Pass Road, Wapato, WA 98951, USA.
| | - Boyd A Mori
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden; Department of Agricultural, Food and Nutritional Science, 4-10 Agriculture/Forestry Centre, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
| | - Alberto M Cattaneo
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
| | - Francisco Gonzalez
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden; Department of Research and Development, ChemTica Internacional S.A., Apdo. 640-3100, Santo Domingo, Heredia, Costa Rica.
| | - Peter Witzgall
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
| | - Paul G Becher
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
| |
Collapse
|
13
|
King BH, Gunathunga PB. Gustation in insects: taste qualities and types of evidence used to show taste function of specific body parts. JOURNAL OF INSECT SCIENCE (ONLINE) 2023; 23:11. [PMID: 37014302 PMCID: PMC10072106 DOI: 10.1093/jisesa/iead018] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/03/2023] [Accepted: 03/10/2023] [Indexed: 06/19/2023]
Abstract
The insect equivalent of taste buds are gustatory sensilla, which have been found on mouthparts, pharynxes, antennae, legs, wings, and ovipositors. Most gustatory sensilla are uniporous, but not all apparently uniporous sensilla are gustatory. Among sensilla containing more than one neuron, a tubular body on one dendrite is also indicative of a taste sensillum, with the tubular body adding tactile function. But not all taste sensilla are also tactile. Additional morphological criteria are often used to recognize if a sensillum is gustatory. Further confirmation of such criteria by electrophysiological or behavioral evidence is needed. The five canonical taste qualities to which insects respond are sweet, bitter, sour, salty, and umami. But not all tastants that insects respond to easily fit in these taste qualities. Categories of insect tastants can be based not only on human taste perception, but also on whether the response is deterrent or appetitive and on chemical structure. Other compounds that at least some insects taste include, but are not limited to: water, fatty acids, metals, carbonation, RNA, ATP, pungent tastes as in horseradish, bacterial lipopolysaccharides, and contact pheromones. We propose that, for insects, taste be defined not only as a response to nonvolatiles but also be restricted to responses that are, or are thought to be, mediated by a sensillum. This restriction is useful because some of the receptor proteins in gustatory sensilla are also found elsewhere.
Collapse
Affiliation(s)
- B H King
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA
| | | |
Collapse
|
14
|
Wosniack ME, Festa D, Hu N, Gjorgjieva J, Berni J. Adaptation of Drosophila larva foraging in response to changes in food resources. eLife 2022; 11:e75826. [PMID: 36458693 PMCID: PMC9822246 DOI: 10.7554/elife.75826] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 11/29/2022] [Indexed: 12/05/2022] Open
Abstract
All animals face the challenge of finding nutritious resources in a changing environment. To maximize lifetime fitness, the exploratory behavior has to be flexible, but which behavioral elements adapt and what triggers those changes remain elusive. Using experiments and modeling, we characterized extensively how Drosophila larvae foraging adapts to different food quality and distribution and how the foraging genetic background influences this adaptation. Our work shows that different food properties modulated specific motor programs. Food quality controls the traveled distance by modulating crawling speed and frequency of pauses and turns. Food distribution, and in particular the food-no food interface, controls turning behavior, stimulating turns toward the food when reaching the patch border and increasing the proportion of time spent within patches of food. Finally, the polymorphism in the foraging gene (rover-sitter) of the larvae adjusts the magnitude of the behavioral response to different food conditions. This study defines several levels of control of foraging and provides the basis for the systematic identification of the neuronal circuits and mechanisms controlling each behavioral response.
Collapse
Affiliation(s)
- Marina E Wosniack
- Computation in Neural Circuits Group, Max Planck Institute for Brain ResearchFrankfurtGermany
| | - Dylan Festa
- School of Life Sciences, Technical University of MunichMunichGermany
| | - Nan Hu
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Julijana Gjorgjieva
- Computation in Neural Circuits Group, Max Planck Institute for Brain ResearchFrankfurtGermany
- School of Life Sciences, Technical University of MunichMunichGermany
| | - Jimena Berni
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Brighton and Sussex Medical School,, University of SussexBrightonUnited Kingdom
| |
Collapse
|
15
|
Ohhara Y, Yamanaka N. Internal sensory neurons regulate stage-specific growth in Drosophila. Development 2022; 149:dev200440. [PMID: 36227580 PMCID: PMC10496149 DOI: 10.1242/dev.200440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 09/22/2022] [Indexed: 09/15/2023]
Abstract
Animals control their developmental schedule in accordance with internal states and external environments. In Drosophila larvae, it is well established that nutrient status is sensed by different internal organs, which in turn regulate production of insulin-like peptides and thereby control growth. In contrast, the impact of the chemosensory system on larval development remains largely unclear. Here, we performed a genetic screen to identify gustatory receptor (Gr) neurons regulating growth and development, and found that Gr28a-expressing neurons are required for proper progression of larval growth. Gr28a is expressed in a subset of peripheral internal sensory neurons, which directly extend their axons to insulin-producing cells (IPCs) in the central nervous system. Silencing of Gr28a-expressing neurons blocked insulin-like peptide release from IPCs and suppressed larval growth during the mid-larval period. These results indicate that Gr28a-expressing neurons promote larval development by directly regulating growth-promoting endocrine signaling in a stage-specific manner.
Collapse
Affiliation(s)
- Yuya Ohhara
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Naoki Yamanaka
- Department of Entomology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA 92521, USA
| |
Collapse
|
16
|
Masuzzo A, Manière G, Grosjean Y, Kurz L, Royet J. Bacteria-Derived Peptidoglycan Triggers a Noncanonical Nuclear Factor-κB-Dependent Response in Drosophila Gustatory Neurons. J Neurosci 2022; 42:7809-7823. [PMID: 36414007 PMCID: PMC9581565 DOI: 10.1523/jneurosci.2437-21.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 12/14/2022] Open
Abstract
Probing the external world is essential for eukaryotes to distinguish beneficial from pathogenic micro-organisms. If it is clear that the main part of this task falls to the immune cells, recent work shows that neurons can also detect microbes, although the molecules and mechanisms involved are less characterized. In Drosophila, detection of bacteria-derived peptidoglycan by pattern recognition receptors of the peptidoglycan recognition protein (PGRP) family expressed in immune cells triggers nuclear factor-κB (NF-κB)/immune deficiency (IMD)-dependent signaling. We show here that one PGRP protein, called PGRP-LB, is expressed in bitter gustatory neurons of proboscises. In vivo calcium imaging in female flies reveals that the PGRP/IMD pathway is cell-autonomously required in these neurons to transduce the peptidoglycan signal. We finally show that NF-κB/IMD pathway activation in bitter-sensing gustatory neurons influences fly behavior. This demonstrates that a major immune response elicitor and signaling module are required in the peripheral nervous system to sense the presence of bacteria in the environment.SIGNIFICANCE STATEMENT In addition to the classical immune response, eukaryotes rely on neuronally controlled mechanisms to detect microbes and engage in adapted behaviors. However, the mechanisms of microbe detection by the nervous system are poorly understood. Using genetic analysis and calcium imaging, we demonstrate here that bacteria-derived peptidoglycan can activate bitter gustatory neurons. We further show that this response is mediated by the PGRP-LC membrane receptor and downstream components of a noncanonical NF-κB signaling cascade. Activation of this signaling cascade triggers behavior changes. These data demonstrate that bitter-sensing neurons and immune cells share a common detection and signaling module to either trigger the production of antibacterial effectors or to modulate the behavior of flies that are in contact with bacteria. Because peptidoglycan detection doesn't mobilize the known gustatory receptors, it also demonstrates that taste perception is much more complex than anticipated.
Collapse
Affiliation(s)
- Ambra Masuzzo
- Centre National de la Recherche Scientifique, Aix-Marseille Université, Institut de Biologie du Developpement de Marseille, 13009 Marseille, France
| | - Gérard Manière
- Centre National de la Recherche Scientifique; Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement; Université Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, L'Institut Agro Dijon, Dijon 21000, France
| | - Yaël Grosjean
- Centre National de la Recherche Scientifique; Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement; Université Bourgogne Franche-Comté, Centre des Sciences du Goût et de l'Alimentation, L'Institut Agro Dijon, Dijon 21000, France
| | - Léopold Kurz
- Centre National de la Recherche Scientifique, Aix-Marseille Université, Institut de Biologie du Developpement de Marseille, 13009 Marseille, France
| | - Julien Royet
- Centre National de la Recherche Scientifique, Aix-Marseille Université, Institut de Biologie du Developpement de Marseille, 13009 Marseille, France
| |
Collapse
|
17
|
Zhang G, Cao S, Guo T, Wang H, Qi X, Ren X, Niu C. Identification and expression profiles of gustatory receptor genes in Bactrocera minax larvae (Diptera: Tephritidae): Role of BminGR59f in larval growth. INSECT SCIENCE 2022; 29:1240-1250. [PMID: 35146929 DOI: 10.1111/1744-7917.13014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/03/2022] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Insects employ various types of gustatory receptors (GRs) to identify nutrient-rich food and avoid toxic substances. The larval gustatory system is the critical checkpoint for food acceptance or rejection. As a specialist herbivore, the larvae of Bactrocera minax feed only on unripe citrus fruits. However, how larvae use GRs to check and adapt to the secondary metabolites in unripe citrus fruits remains unknown. In this study, we first performed developmental expression profiles showing that most BminGRs genes were highly expressed in 1st and 2nd instar larvae and that tissue-specific expression indicated high expression of most BminGRs genes in the mouthparts of 2nd instar larvae. Furthermore, we found that silencing BminGR59f by RNA interference (RNAi) affected the growth of 2nd instar B. minax larvae. Hesperidin and naringin were screened as ligands of BminGR59f via RNAi and cell calcium imaging, and the combination of these two flavones increased the body weight of larvae. In summary, we identified a novel gustatory perception pattern in B. minax for detecting hesperidin and naringin, which boosted the growth of B. minax larvae. These results shed light on how specialist herbivores detect and adapt to host metabolites in adverse environments depending on larval GRs.
Collapse
Affiliation(s)
- Guijian Zhang
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
| | - Shuai Cao
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
| | - Tong Guo
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
| | - Haoran Wang
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
| | - Xuewei Qi
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
| | - Xueming Ren
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
| | - Changying Niu
- Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
18
|
Ai D, Dong C, Yang B, Yu C, Wang G. A fructose receptor gene influences development and feed intake in Helicoverpa armigera. INSECT SCIENCE 2022; 29:993-1005. [PMID: 34780113 DOI: 10.1111/1744-7917.12984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
Gustatory receptors (GRs) are critical for multiple life activities of insects. Owing to the rapid development of genome and transcriptome sequencing, numerous insect GRs have been identified. However, the expression patterns and functions of these receptors are poorly understood. In this study, we analyzed the expression pattern of GRs in Helicoverpa armigera and found that the fructose receptor HarmGR9 was highly expressed in the foregut and abdomen. The function of HarmGR9 was identified using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system. Knockout of the HarmGR9 gene shortened the developmental period of the larval stages and increased food consumption in both larvae and adults. This study revealed the tissue distribution of sugar-sense-related receptors in H. armigera and thereby expanded the understanding of insect feeding regulation.
Collapse
Affiliation(s)
- Dong Ai
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chenxi Dong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Bin Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Caihong Yu
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, China
| | - Guirong Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- Guangdong Laboratory of Lingnan Modern Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, Guangdong Province, China
| |
Collapse
|
19
|
Nutrient Sensing via Gut in Drosophila melanogaster. Int J Mol Sci 2022; 23:ijms23052694. [PMID: 35269834 PMCID: PMC8910450 DOI: 10.3390/ijms23052694] [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: 10/30/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 01/08/2023] Open
Abstract
Nutrient-sensing mechanisms in animals' sense available nutrients to generate a physiological regulatory response involving absorption, digestion, and regulation of food intake and to maintain glucose and energy homeostasis. During nutrient sensing via the gastrointestinal tract, nutrients interact with receptors on the enteroendocrine cells in the gut, which in return respond by secreting various hormones. Sensing of nutrients by the gut plays a critical role in transmitting food-related signals to the brain and other tissues informing the composition of ingested food to digestive processes. These signals modulate feeding behaviors, food intake, metabolism, insulin secretion, and energy balance. The increasing significance of fly genetics with the availability of a vast toolbox for studying physiological function, expression of chemosensory receptors, and monitoring the gene expression in specific cells of the intestine makes the fly gut the most useful tissue for studying the nutrient-sensing mechanisms. In this review, we emphasize on the role of Drosophila gut in nutrient-sensing to maintain metabolic homeostasis and gut-brain cross talk using endocrine and neuronal signaling pathways stimulated by internal state or the consumption of various dietary nutrients. Overall, this review will be useful in understanding the post-ingestive nutrient-sensing mechanisms having a physiological and pathological impact on health and diseases.
Collapse
|
20
|
Genome-wide identification and expression pattern analysis of novel chemosensory genes in the German cockroach Blattella germanica. Genomics 2022; 114:110310. [DOI: 10.1016/j.ygeno.2022.110310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 02/03/2022] [Accepted: 02/05/2022] [Indexed: 11/21/2022]
|
21
|
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
|
22
|
Maier GL, Komarov N, Meyenhofer F, Kwon JY, Sprecher SG. Taste sensing and sugar detection mechanisms in Drosophila larval primary taste center. eLife 2021; 10:67844. [PMID: 34859782 PMCID: PMC8709573 DOI: 10.7554/elife.67844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 11/23/2021] [Indexed: 11/25/2022] Open
Abstract
Despite the small number of gustatory sense neurons, Drosophila larvae are able to sense a wide range of chemicals. Although evidence for taste multimodality has been provided in single neurons, an overview of gustatory responses at the periphery is missing and hereby we explore whole-organ calcium imaging of the external taste center. We find that neurons can be activated by different combinations of taste modalities, including opposite hedonic valence and identify distinct temporal dynamics of response. Although sweet sensing has not been fully characterized so far in the external larval gustatory organ, we recorded responses elicited by sugar. Previous findings established that larval sugar sensing relies on the Gr43a pharyngeal receptor, but the question remains if external neurons contribute to this taste. Here, we postulate that external and internal gustation use distinct and complementary mechanisms in sugar sensing and we identify external sucrose sensing neurons.
Collapse
Affiliation(s)
- G Larisa Maier
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Nikita Komarov
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Felix Meyenhofer
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Republic of Korea
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| |
Collapse
|
23
|
Komarov N, Sprecher SG. The chemosensory system of the Drosophila larva: an overview of current understanding. Fly (Austin) 2021; 16:1-12. [PMID: 34612150 PMCID: PMC8496535 DOI: 10.1080/19336934.2021.1953364] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Animals must sense their surroundings and be able to distinguish between relevant and irrelevant cues. An enticing area of research aims to uncover the mechanisms by which animals respond to chemical signals that constitute critical sensory input. In this review, we describe the principles of a model chemosensory system: the Drosophila larva. While distinct in many ways, larval behaviour is reminiscent of the dogmatic goals of life: to reach a stage of reproductive potential. It takes into account a number of distinct and identifiable parameters to ultimately provoke or modulate appropriate behavioural output. In this light, we describe current knowledge of chemosensory anatomy, genetic components, and the processing logic of chemical cues. We outline recent advancements and summarize the hypothesized neural circuits of sensory systems. Furthermore, we note yet-unanswered questions to create a basis for further investigation of molecular and systemic mechanisms of chemosensation in Drosophila and beyond.
Collapse
Affiliation(s)
- Nikita Komarov
- Institute of Cell and Developmental Biology, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Simon G Sprecher
- Institute of Cell and Developmental Biology, Department of Biology, University of Fribourg, Fribourg, Switzerland
| |
Collapse
|
24
|
Drosophila Corazonin Neurons as a Hub for Regulating Growth, Stress Responses, Ethanol-Related Behaviors, Copulation Persistence and Sexually Dimorphic Reward Pathways. J Dev Biol 2021; 9:jdb9030026. [PMID: 34287347 PMCID: PMC8293205 DOI: 10.3390/jdb9030026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
The neuronal mechanisms by which complex behaviors are coordinated and timed often involve neuropeptidergic regulation of stress and reward pathways. Recent studies of the neuropeptide Corazonin (Crz), a homolog of the mammalian Gonadotrophin Releasing Hormone (GnRH), have suggested its crucial role in the regulation of growth, internal states and behavioral decision making. We focus this review on Crz neurons with the goal to (1) highlight the diverse roles of Crz neuron function, including mechanisms that may be independent of the Crz peptide, (2) emphasize current gaps in knowledge about Crz neuron functions, and (3) propose exciting ideas of novel research directions involving the use of Crz neurons. We describe the different developmental fates of distinct subsets of Crz neurons, including recent findings elucidating the molecular regulation of apoptosis. Crz regulates systemic growth, food intake, stress responses and homeostasis by interacting with the short Neuropeptide F (sNPF) and the steroid hormone ecdysone. Additionally, activation of Crz neurons is shown to be pleasurable by interacting with the Neuropeptide F (NPF) and regulates reward processes such as ejaculation and ethanol-related behaviors in a sexually dimorphic manner. Crz neurons are proposed to be a motivational switch regulating copulation duration using a CaMKII-dependent mechanism described as the first neuronal interval timer lasting longer than a few seconds. Lastly, we propose ideas to use Crz neuron-induced ejaculation to study the effects of fictive mating and sex addiction in flies, as well as to elucidate dimorphic molecular mechanisms underlying reward behaviors and feeding disorders.
Collapse
|
25
|
The plant metabolome guides fitness-relevant foraging decisions of a specialist herbivore. PLoS Biol 2021; 19:e3001114. [PMID: 33600420 PMCID: PMC7924754 DOI: 10.1371/journal.pbio.3001114] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 03/02/2021] [Accepted: 01/26/2021] [Indexed: 01/01/2023] Open
Abstract
Plants produce complex mixtures of primary and secondary metabolites. Herbivores use these metabolites as behavioral cues to increase their fitness. However, how herbivores combine and integrate different metabolite classes into fitness-relevant foraging decisions in planta is poorly understood. We developed a molecular manipulative approach to modulate the availability of sugars and benzoxazinoid secondary metabolites as foraging cues for a specialist maize herbivore, the western corn rootworm. By disrupting sugar perception in the western corn rootworm and benzoxazinoid production in maize, we show that sugars and benzoxazinoids act as distinct and dynamically combined mediators of short-distance host finding and acceptance. While sugars improve the capacity of rootworm larvae to find a host plant and to distinguish postembryonic from less nutritious embryonic roots, benzoxazinoids are specifically required for the latter. Host acceptance in the form of root damage is increased by benzoxazinoids and sugars in an additive manner. This pattern is driven by increasing damage to postembryonic roots in the presence of benzoxazinoids and sugars. Benzoxazinoid- and sugar-mediated foraging directly improves western corn rootworm growth and survival. Interestingly, western corn rootworm larvae retain a substantial fraction of their capacity to feed and survive on maize plants even when both classes of chemical cues are almost completely absent. This study unravels fine-grained differentiation and combination of primary and secondary metabolites into herbivore foraging and documents how the capacity to compensate for the lack of important chemical cues enables a specialist herbivore to survive within unpredictable metabolic landscapes.
Collapse
|
26
|
McMullen E, Weiler A, Becker HM, Schirmeier S. Plasticity of Carbohydrate Transport at the Blood-Brain Barrier. Front Behav Neurosci 2021; 14:612430. [PMID: 33551766 PMCID: PMC7863721 DOI: 10.3389/fnbeh.2020.612430] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/17/2020] [Indexed: 12/21/2022] Open
Abstract
Neuronal function is highly energy demanding, requiring efficient transport of nutrients into the central nervous system (CNS). Simultaneously the brain must be protected from the influx of unwanted solutes. Most of the energy is supplied from dietary sugars, delivered from circulation via the blood-brain barrier (BBB). Therefore, selective transporters are required to shuttle metabolites into the nervous system where they can be utilized. The Drosophila BBB is formed by perineural and subperineurial glial cells, which effectively separate the brain from the surrounding hemolymph, maintaining a constant microenvironment. We identified two previously unknown BBB transporters, MFS3 (Major Facilitator Superfamily Transporter 3), located in the perineurial glial cells, and Pippin, found in both the perineurial and subperineurial glial cells. Both transporters facilitate uptake of circulating trehalose and glucose into the BBB-forming glial cells. RNA interference-mediated knockdown of these transporters leads to pupal lethality. However, null mutants reach adulthood, although they do show reduced lifespan and activity. Here, we report that both carbohydrate transport efficiency and resulting lethality found upon loss of MFS3 or Pippin are rescued via compensatory upregulation of Tret1-1, another BBB carbohydrate transporter, in Mfs3 and pippin null mutants, while RNAi-mediated knockdown is not compensated for. This means that the compensatory mechanisms in place upon mRNA degradation following RNA interference can be vastly different from those resulting from a null mutation.
Collapse
Affiliation(s)
- Ellen McMullen
- Department of Biology, Institute of Zoology, Technische Universität Dresden, Dresden, Germany
| | - Astrid Weiler
- Department of Biology, Institute of Zoology, Technische Universität Dresden, Dresden, Germany
| | - Holger M. Becker
- Division of General Zoology, Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Stefanie Schirmeier
- Department of Biology, Institute of Zoology, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
27
|
Cellular Basis of Bitter-Driven Aversive Behaviors in Drosophila Larva. eNeuro 2020; 7:ENEURO.0510-19.2020. [PMID: 32220859 PMCID: PMC7189479 DOI: 10.1523/eneuro.0510-19.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 03/16/2020] [Accepted: 03/16/2020] [Indexed: 12/04/2022] Open
Abstract
Feeding, a critical behavior for survival, consists of a complex series of behavioral steps. In Drosophila larvae, the initial steps of feeding are food choice, during which the quality of a potential food source is judged, and ingestion, during which the selected food source is ingested into the digestive tract. It remains unclear whether these steps employ different mechanisms of neural perception. Here, we provide insight into the two initial steps of feeding in Drosophila larva. We find that substrate choice and ingestion are determined by independent circuits at the cellular level. First, we took 22 candidate bitter compounds and examined their influence on choice preference and ingestion behavior. Interestingly, certain bitter tastants caused different responses in choice and ingestion, suggesting distinct mechanisms of perception. We further provide evidence that certain gustatory receptor neurons (GRNs) in the external terminal organ (TO) are involved in determining choice preference, and a pair of larval pharyngeal GRNs is involved in mediating both avoidance and suppression of ingestion. Our results show that feeding behavior is coordinated by a multistep regulatory process employing relatively independent neural elements. These findings are consistent with a model in which distinct sensory pathways act as modulatory circuits controlling distinct subprograms during feeding.
Collapse
|
28
|
Wegener C, Hasan G. ER-Ca2+ sensor STIM regulates neuropeptides required for development under nutrient restriction in Drosophila. PLoS One 2019; 14:e0219719. [PMID: 31295329 PMCID: PMC6622525 DOI: 10.1371/journal.pone.0219719] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/28/2019] [Indexed: 12/31/2022] Open
Abstract
Neuroendocrine cells communicate via neuropeptides to regulate behaviour and physiology. This study examines how STIM (Stromal Interacting Molecule), an ER-Ca2+ sensor required for Store-operated Ca2+ entry, regulates neuropeptides required for Drosophila development under nutrient restriction (NR). We find two STIM-regulated peptides, Corazonin and short Neuropeptide F, to be required for NR larvae to complete development. Further, a set of secretory DLP (Dorso lateral peptidergic) neurons which co-express both peptides was identified. Partial loss of dSTIM caused peptide accumulation in the DLPs, and reduced systemic Corazonin signalling. Upon NR, larval development correlated with increased peptide levels in the DLPs, which failed to occur when dSTIM was reduced. Comparison of systemic and cellular phenotypes associated with reduced dSTIM, with other cellular perturbations, along with genetic rescue experiments, suggested that dSTIM primarily compromises neuroendocrine function by interfering with neuropeptide release. Under chronic stimulation, dSTIM also appears to regulate neuropeptide synthesis.
Collapse
Affiliation(s)
- Christian Wegener
- Department of Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, Am Hubland, Würzburg, Germany
| | - Gaiti Hasan
- National Centre For Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
| |
Collapse
|
29
|
Kudow N, Kamikouchi A, Tanimura T. Softness sensing and learning in Drosophila larvae. ACTA ACUST UNITED AC 2019; 222:jeb.196329. [PMID: 30833462 DOI: 10.1242/jeb.196329] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 02/23/2019] [Indexed: 11/20/2022]
Abstract
Mechanosensation provides animals with important sensory information in addition to olfaction and gustation during feeding behavior. Here, we used Drosophila melanogaster larvae to investigate the role of softness sensing in behavior and learning. In the natural environment, larvae need to dig into soft foods for feeding. Finding foods that are soft enough to dig into is likely to be essential for their survival. We report that larvae can discriminate between different agar concentrations and prefer softer agar. Interestingly, we show that larvae on a harder surface search for a softer surface using memory associated with an odor, and that they evaluate foods by balancing softness and sweetness. These findings suggest that larvae integrate mechanosensory information with chemosensory input while foraging. Moreover, we found that the larval preference for softness is affected by genetic background.
Collapse
Affiliation(s)
- Nana Kudow
- Department of Biology, Faculty of Science, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan.,Division of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Aichi 464-8602, Japan
| | - Azusa Kamikouchi
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Aichi 464-8602, Japan
| | - Teiichi Tanimura
- Department of Biology, Faculty of Science, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan .,Division of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Aichi 464-8602, Japan.,Department of Genetics, Leibniz Institute for Neurobiology (LIN), Brenneckestr. 6, 39118 Magdeburg, Germany
| |
Collapse
|
30
|
A single pair of leucokinin neurons are modulated by feeding state and regulate sleep-metabolism interactions. PLoS Biol 2019; 17:e2006409. [PMID: 30759083 PMCID: PMC6391015 DOI: 10.1371/journal.pbio.2006409] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 02/26/2019] [Accepted: 01/25/2019] [Indexed: 12/25/2022] Open
Abstract
Dysregulation of sleep and feeding has widespread health consequences. Despite extensive epidemiological evidence for interactions between sleep and metabolic function, little is known about the neural or molecular basis underlying the integration of these processes. D. melanogaster potently suppress sleep in response to starvation, and powerful genetic tools allow for mechanistic investigation of sleep–metabolism interactions. We have previously identified neurons expressing the neuropeptide leucokinin (Lk) as being required for starvation-mediated changes in sleep. Here, we demonstrate an essential role for Lk neuropeptide in metabolic regulation of sleep. The activity of Lk neurons is modulated by feeding, with reduced activity in response to glucose and increased activity under starvation conditions. Both genetic silencing and laser-mediated microablation localize Lk-dependent sleep regulation to a single pair of Lk neurons within the Lateral Horn (LHLK neurons). A targeted screen identified a role for 5′ adenosine monophosphate-activated protein kinase (AMPK) in starvation-modulated changes in sleep. Knockdown of AMPK in Lk neurons suppresses sleep and increases LHLK neuron activity in fed flies, phenocopying the starvation state. Further, we find a requirement for the Lk receptor in the insulin-producing cells (IPCs), suggesting LHLK–IPC connectivity is critical for sleep regulation under starved conditions. Taken together, these findings localize feeding-state–dependent regulation of sleep to a single pair of neurons within the fruit fly brain and provide a system for investigating the cellular basis of sleep–metabolism interactions. Neural regulation of sleep and feeding are interconnected and are critical for survival. Many animals reduce their sleep in response to starvation, presumably to forage for food. Here, we find that in the fruit fly Drosophila melanogaster, the neuropeptide leucokinin is required for the modulation of starvation-dependent changes in sleep. Leucokinin is expressed in numerous populations of neurons within the two compartments of the central nervous system: the brain and the ventral nerve cord. Both genetic manipulation and laser-mediated microablation experiments identify a single pair of neurons expressing this neuropeptide in the brain as being required for metabolic regulation of sleep. These neurons become active during periods of starvation and modulate the function of insulin-producing cells that are critical modulators of both sleep and feeding. Supporting this notion, knockdown of the leucokinin receptor within the insulin-producing cells also disrupts metabolic regulation of sleep. Taken together, these findings identify a critical role for leucokinin signaling in the integration of sleep and feeding states.
Collapse
|
31
|
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
|
32
|
Miguel-Aliaga I, Jasper H, Lemaitre B. Anatomy and Physiology of the Digestive Tract of Drosophila melanogaster. Genetics 2018; 210:357-396. [PMID: 30287514 PMCID: PMC6216580 DOI: 10.1534/genetics.118.300224] [Citation(s) in RCA: 257] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/26/2018] [Indexed: 12/15/2022] Open
Abstract
The gastrointestinal tract has recently come to the forefront of multiple research fields. It is now recognized as a major source of signals modulating food intake, insulin secretion and energy balance. It is also a key player in immunity and, through its interaction with microbiota, can shape our physiology and behavior in complex and sometimes unexpected ways. The insect intestine had remained, by comparison, relatively unexplored until the identification of adult somatic stem cells in the Drosophila intestine over a decade ago. Since then, a growing scientific community has exploited the genetic amenability of this insect organ in powerful and creative ways. By doing so, we have shed light on a broad range of biological questions revolving around stem cells and their niches, interorgan signaling and immunity. Despite their relatively recent discovery, some of the mechanisms active in the intestine of flies have already been shown to be more widely applicable to other gastrointestinal systems, and may therefore become relevant in the context of human pathologies such as gastrointestinal cancers, aging, or obesity. This review summarizes our current knowledge of both the formation and function of the Drosophila melanogaster digestive tract, with a major focus on its main digestive/absorptive portion: the strikingly adaptable adult midgut.
Collapse
Affiliation(s)
- Irene Miguel-Aliaga
- Medical Research Council London Institute of Medical Sciences, Imperial College London, W12 0NN, United Kingdom
| | - Heinrich Jasper
- Buck Institute for Research on Aging, Novato, California 94945-1400
- Immunology Discovery, Genentech, Inc., San Francisco, California 94080
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| |
Collapse
|
33
|
Mishra D, Thorne N, Miyamoto C, Jagge C, Amrein H. The taste of ribonucleosides: Novel macronutrients essential for larval growth are sensed by Drosophila gustatory receptor proteins. PLoS Biol 2018; 16:e2005570. [PMID: 30086130 PMCID: PMC6080749 DOI: 10.1371/journal.pbio.2005570] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 06/27/2018] [Indexed: 02/04/2023] Open
Abstract
Animals employ various types of taste receptors to identify and discriminate between different nutritious food chemicals. These macronutrients are thought to fall into 3 major groups: carbohydrates/sugars, proteins/amino acids, and fats. Here, we report that Drosophila larvae exhibit a novel appetitive feeding behavior towards ribose, ribonucleosides, and RNA. We identified members of the gustatory receptor (Gr) subfamily 28 (Gr28), expressed in both external and internal chemosensory neurons as molecular receptors necessary for cellular and appetitive behavioral responses to ribonucleosides and RNA. Specifically, behavioral preference assays show that larvae are strongly attracted to ribose- or RNA-containing agarose in a Gr28-dependent manner. Moreover, Ca2+ imaging experiments reveal that Gr28a-expressing taste neurons are activated by ribose, RNA and some ribonucleosides and that these responses can be conveyed to Gr43aGAL4 fructose-sensing neurons by expressing single members of the Gr28 gene family. Lastly, we establish a critical role in behavioral fitness for the Gr28 genes by showing that Gr28 mutant larvae exhibit low survival rates when challenged to find ribonucleosides in food. Together, our work identifies a novel taste modality dedicated to the detection of RNA and ribonucleosides, nutrients that are essential for survival during the accelerated growth phase of Drosophila larvae. Insects that undergo complete metamorphosis grow only during the larval stage of development. In many species, this period is restricted to a few days, during which larvae might increase their weight up to several hundred-fold. Drosophila melanogaster, for example, grow from a tiny first-instar larva of about 10 μg to a wandering third-instar larva weighing about 2 mg over a period of only 4.5 days. The main macronutrients known to be critical for this period of rapid growth are amino acids and sugars. In this study, we identify ribonucleosides and RNA as a new, additional type of nutrient necessary for rapid larval growth and survival. We show that larvae harbor taste neurons that express taste receptors necessary for sensing ribonucleosides and RNA. Larvae lacking these taste receptors show high mortality rates when exposed to a complex food environment that requires the location of ribonucleoside-containing food. We hypothesize that the ability to taste RNA evolved as a new taste modality in larvae of insects that go through a rapid growth period because ingestion of ribonucleosides, as opposed to de novo synthesis, provides a survival advantage during a period of extreme growth.
Collapse
Affiliation(s)
- Dushyant Mishra
- Texas A&M Health Science Center, Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Natasha Thorne
- Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland, United States of America
| | - Chika Miyamoto
- Texas A&M Health Science Center, Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Christopher Jagge
- Texas A&M Health Science Center, Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Hubert Amrein
- Texas A&M Health Science Center, Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
| |
Collapse
|
34
|
Pavin A, Fain K, DeHart A, Sitaraman D. Aversive and Appetitive Learning in Drosophila Larvae: A Simple and Powerful Suite of Laboratory Modules for Classroom or Open-ended Research Projects. JOURNAL OF UNDERGRADUATE NEUROSCIENCE EDUCATION : JUNE : A PUBLICATION OF FUN, FACULTY FOR UNDERGRADUATE NEUROSCIENCE 2018; 16:A177-A185. [PMID: 30057500 PMCID: PMC6057766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/27/2018] [Accepted: 04/28/2018] [Indexed: 06/08/2023]
Abstract
A key element of laboratory courses introducing students to neuroscience includes behavioral exercises. Associative learning experiments often conducted in research laboratories are difficult to perform and time consuming. Commonly, these experiments cannot be performed without extensive instrumentation or animal care facilities. Here, we describe three distinct laboratory modules that build on simple chemosensory and memory assays in Drosophila larvae. Additionally, we describe open-ended research projects using these assays that can be developed into semester long independent research experiences. Given that Drosophila is a genetic model organism, these simple behavioral assays can be used to generate multiple hypothesis driven projects aimed at identifying a gene or class of neurons involved in appetitive and aversive learning. These lab modules are ideally suited for undergraduates at all levels to experience and can be incorporated in a lower/upper level neuroscience course or as a high school outreach exercise. Further, these modules enable students to collect their own data sets, work in groups in collating large data sets, performing statistical comparisons, and presenting results in the form of short research papers or traditional laboratory reports that include a short literature review.
Collapse
Affiliation(s)
- Austin Pavin
- Department of Psychological Sciences, College of Arts and Sciences, University of San Diego, San Diego, CA-92110
| | - Kevin Fain
- Department of Psychological Sciences, College of Arts and Sciences, University of San Diego, San Diego, CA-92110
| | - Allison DeHart
- Department of Psychological Sciences, College of Arts and Sciences, University of San Diego, San Diego, CA-92110
| | - Divya Sitaraman
- Department of Psychological Sciences, College of Arts and Sciences, University of San Diego, San Diego, CA-92110
| |
Collapse
|
35
|
Staats S, Lüersen K, Wagner AE, Rimbach G. Drosophila melanogaster as a Versatile Model Organism in Food and Nutrition Research. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:3737-3753. [PMID: 29619822 DOI: 10.1021/acs.jafc.7b05900] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Drosophila melanogaster has been widely used in the biological sciences as a model organism. Drosophila has a relatively short life span of 60-80 days, which makes it attractive for life span studies. Moreover, approximately 60% of the fruit fly genes are orthologs to mammals. Thus, metabolic and signal transduction pathways are highly conserved. Maintenance and reproduction of Drosophila do not require sophisticated equipment and are rather cheap. Furthermore, there are fewer ethical issues involved in experimental Drosophila research compared with studies in laboratory rodents, such as rats and mice. Drosophila is increasingly recognized as a model organism in food and nutrition research. Drosophila is often fed complex solid diets based on yeast, corn, and agar. There are also so-called holidic diets available that are defined in terms of their amino acid, fatty acid, carbohydrate, vitamin, mineral, and trace element compositions. Feed intake, body composition, locomotor activity, intestinal barrier function, microbiota, cognition, fertility, aging, and life span can be systematically determined in Drosophila in response to dietary factors. Furthermore, diet-induced pathophysiological mechanisms including inflammation and stress responses may be evaluated in the fly under defined experimental conditions. Here, we critically evaluate Drosophila melanogaster as a versatile model organism in experimental food and nutrition research, review the corresponding data in the literature, and make suggestions for future directions of research.
Collapse
Affiliation(s)
- Stefanie Staats
- Institute of Human Nutrition and Food Science , University of Kiel , Hermann-Rodewald-Strasse 6 , D-24118 Kiel , Germany
| | - Kai Lüersen
- Institute of Human Nutrition and Food Science , University of Kiel , Hermann-Rodewald-Strasse 6 , D-24118 Kiel , Germany
| | - Anika E Wagner
- Institute of Nutritional Medicine , University of Lübeck , Ratzeburger Allee 160 , D-23538 Lübeck , Germany
| | - Gerald Rimbach
- Institute of Human Nutrition and Food Science , University of Kiel , Hermann-Rodewald-Strasse 6 , D-24118 Kiel , Germany
| |
Collapse
|
36
|
Jayakumar S, Hasan G. Neuronal Calcium Signaling in Metabolic Regulation and Adaptation to Nutrient Stress. Front Neural Circuits 2018; 12:25. [PMID: 29674958 PMCID: PMC5895653 DOI: 10.3389/fncir.2018.00025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 03/02/2018] [Indexed: 01/13/2023] Open
Abstract
All organisms can respond physiologically and behaviorally to environmental fluxes in nutrient levels. Different nutrient sensing pathways exist for specific metabolites, and their inputs ultimately define appropriate nutrient uptake and metabolic homeostasis. Nutrient sensing mechanisms at the cellular level require pathways such as insulin and target of rapamycin (TOR) signaling that integrates information from different organ systems like the fat body and the gut. Such integration is essential for coordinating growth with development. Here we review the role of a newly identified set of integrative interneurons and the role of intracellular calcium signaling within these neurons, in regulating nutrient sensing under conditions of nutrient stress. A comparison of the identified Drosophila circuit and cellular mechanisms employed in this circuit, with vertebrate systems, suggests that the identified cell signaling mechanisms may be conserved for neural circuit function related to nutrient sensing by central neurons. The ideas proposed are potentially relevant for understanding the molecular basis of metabolic disorders, because these are frequently linked to nutritional stress.
Collapse
Affiliation(s)
- Siddharth Jayakumar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| |
Collapse
|
37
|
Widmann A, Eichler K, Selcho M, Thum AS, Pauls D. Odor-taste learning in Drosophila larvae. JOURNAL OF INSECT PHYSIOLOGY 2018; 106:47-54. [PMID: 28823531 DOI: 10.1016/j.jinsphys.2017.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/07/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
The Drosophila larva is an attractive model system to study fundamental questions in the field of neuroscience. Like the adult fly, the larva offers a seemingly unlimited genetic toolbox, which allows one to visualize, silence or activate neurons down to the single cell level. This, combined with its simplicity in terms of cell numbers, offers a useful system to study the neuronal correlates of complex processes including associative odor-taste learning and memory formation. Here, we summarize the current knowledge about odor-taste learning and memory at the behavioral level and integrate the recent progress on the larval connectome to shed light on the sub-circuits that allow Drosophila larvae to integrate present sensory input in the context of past experience and to elicit an appropriate behavioral response.
Collapse
Affiliation(s)
| | - Katharina Eichler
- Department of Biology, University of Konstanz, D-78464 Konstanz, Germany; HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Mareike Selcho
- Department of Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, D-97074 Würzburg, Germany
| | - Andreas S Thum
- Department of Biology, University of Konstanz, D-78464 Konstanz, Germany; Department of Genetics, University of Leipzig, D-04103 Leipzig, Germany.
| | - Dennis Pauls
- Department of Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, D-97074 Würzburg, Germany.
| |
Collapse
|
38
|
Functional architecture of reward learning in mushroom body extrinsic neurons of larval Drosophila. Nat Commun 2018; 9:1104. [PMID: 29549237 PMCID: PMC5856778 DOI: 10.1038/s41467-018-03130-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 01/22/2018] [Indexed: 01/01/2023] Open
Abstract
The brain adaptively integrates present sensory input, past experience, and options for future action. The insect mushroom body exemplifies how a central brain structure brings about such integration. Here we use a combination of systematic single-cell labeling, connectomics, transgenic silencing, and activation experiments to study the mushroom body at single-cell resolution, focusing on the behavioral architecture of its input and output neurons (MBINs and MBONs), and of the mushroom body intrinsic APL neuron. Our results reveal the identity and morphology of almost all of these 44 neurons in stage 3 Drosophila larvae. Upon an initial screen, functional analyses focusing on the mushroom body medial lobe uncover sparse and specific functions of its dopaminergic MBINs, its MBONs, and of the GABAergic APL neuron across three behavioral tasks, namely odor preference, taste preference, and associative learning between odor and taste. Our results thus provide a cellular-resolution study case of how brains organize behavior.
Collapse
|
39
|
Genetic and Neurobiological Analyses of the Noradrenergic-like System in Vulnerability to Sugar Overconsumption Using a Drosophila Model. Sci Rep 2017; 7:17642. [PMID: 29247240 PMCID: PMC5732301 DOI: 10.1038/s41598-017-17760-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 11/30/2017] [Indexed: 12/22/2022] Open
Abstract
Regular overconsumption of sugar is associated with obesity and type-2 diabetes, but how genetic factors contribute to variable sugar preferences and intake levels remains mostly unclear. Here we provide evidence for the usefulness of a Drosophila larva model to investigate genetic influence on vulnerability to sugar overconsumption. Using genetic and RNA interference approaches, we show that the activity of the Oamb gene, which encodes a receptor for octopamine (OA, the invertebrate homologue of norepinephrine), plays a major role in controlled sugar consumption. Furthermore, Oamb appears to suppress sugar food intake in fed larvae in an acute manner, and neurons expressing this Oamb receptor do not overlap with neurons expressing Octβ3R, another OA receptor previously implicated in hunger-driven exuberant sugar intake. Together, these results suggest that two separate sub-circuits, defined by Oamb and Octβ3R respectively, co-regulate sugar consumption according to changes in energy needs. We propose that the noradrenergic-like system defines an ancient regulatory mechanism for prevention of sugar overload.
Collapse
|
40
|
Xu W, Liu N, Liao Y, Anderson A. Molecular characterization of sugar taste receptors in the cotton bollworm Helicoverpa armigera. Genome 2017; 60:1037-1044. [DOI: 10.1139/gen-2017-0086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Insects utilize sugars as their essential energy and nutrient sources; therefore, the sense of sugar detection plays a critical role in insect behaviours. Previously, using genomic and transcriptomic approaches, we identified eight putative sugar gustatory receptor (GR) genes from the cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). Here, we further validated these annotated sugar receptor genes (HarmGr4–HarmGr8 and HarmGr10–HarmGr12) and found HarmGr10 may be a pseudogene carrying a stop codon in the open reading frame. Sequence alignment revealed H. armigera sugar GR sequences are conserved at C-terminus and phylogenetic analysis showed that insect sugar GRs have evolved in a family-specific manner. Interestingly, all eight H. armigera sugar GRs are localized in a tandem array on the same scaffold of the genome. In silico gene expression and reverse transcription (RT)-PCR analysis showed that HarmGr10 is specifically expressed in male adult testes while HarmGr11 is specifically expressed in female adult ovaries, suggesting H. armigera sugar GRs may be involved in reproduction-related functions. This study improves our knowledge on insect sugar receptors and gustatory systems.
Collapse
Affiliation(s)
- Wei Xu
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Naiyong Liu
- Key Laboratory of Forest Disaster Warning and Control of Yunnan Province, Southwest Forestry University, Kunming 650224, China
| | - Yalin Liao
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Alisha Anderson
- CSIRO Ecosystem Sciences, Black Mountain, ACT 2601, Australia
| |
Collapse
|
41
|
The Neuropeptide Corazonin Controls Social Behavior and Caste Identity in Ants. Cell 2017; 170:748-759.e12. [PMID: 28802044 DOI: 10.1016/j.cell.2017.07.014] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 05/23/2017] [Accepted: 07/13/2017] [Indexed: 11/21/2022]
Abstract
Social insects are emerging models to study how gene regulation affects behavior because their colonies comprise individuals with the same genomes but greatly different behavioral repertoires. To investigate the molecular mechanisms that activate distinct behaviors in different castes, we exploit a natural behavioral plasticity in Harpegnathos saltator, where adult workers can transition to a reproductive, queen-like state called gamergate. Analysis of brain transcriptomes during the transition reveals that corazonin, a neuropeptide homologous to the vertebrate gonadotropin-releasing hormone, is downregulated as workers become gamergates. Corazonin is also preferentially expressed in workers and/or foragers from other social insect species. Injection of corazonin in transitioning Harpegnathos individuals suppresses expression of vitellogenin in the brain and stimulates worker-like hunting behaviors, while inhibiting gamergate behaviors, such as dueling and egg deposition. We propose that corazonin is a central regulator of caste identity and behavior in social insects.
Collapse
|
42
|
Kim H, Jeong YT, Choi MS, Choi J, Moon SJ, Kwon JY. Involvement of a Gr2a-Expressing Drosophila Pharyngeal Gustatory Receptor Neuron in Regulation of Aversion to High-Salt Foods. Mol Cells 2017; 40:331-338. [PMID: 28535667 PMCID: PMC5463041 DOI: 10.14348/molcells.2017.0028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/03/2017] [Accepted: 04/18/2017] [Indexed: 11/27/2022] Open
Abstract
Regulation of feeding is essential for animal survival. The pharyngeal sense organs can act as a second checkpoint of food quality, due to their position between external taste organs such as the labellum which initially assess food quality, and the digestive tract. Growing evidence provides support that the pharyngeal sensory neurons regulate feeding, but much is still unknown. We found that a pair of gustatory receptor neurons in the LSO, a Drosophila adult pharyngeal organ which expresses four gustatory receptors, is involved in feeding inhibition in response to high concentrations of sodium ions. RNAi experiments and mutant analysis showed that the gustatory receptor Gr2a is necessary for this process. This feeding preference determined by whether a food source is perceived as appetizing or not is influenced by nutritional conditions, such that when the animal is hungry, the need for energy dominates over how appealing the food source is. Our results provide experimental evidence that factors involved in feeding function in a context-dependent manner.
Collapse
Affiliation(s)
- Haein Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - Yong Taek Jeong
- Department of Oral Biology, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul 03722,
Korea
| | - Min Sung Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - Jaekyun Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| | - Seok Jun Moon
- Department of Oral Biology, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul 03722,
Korea
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419,
Korea
| |
Collapse
|
43
|
Chng WBA, Hietakangas V, Lemaitre B. Physiological Adaptations to Sugar Intake: New Paradigms from Drosophila melanogaster. Trends Endocrinol Metab 2017; 28:131-142. [PMID: 27923532 DOI: 10.1016/j.tem.2016.11.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/30/2016] [Accepted: 11/07/2016] [Indexed: 11/20/2022]
Abstract
Sugars are important energy sources, but high sugar intake poses a metabolic challenge and leads to diseases. Drosophila melanogaster is a generalist fruit breeder that encounters high levels of dietary sugars in its natural habitat. Consequently, Drosophila displays adaptive responses to dietary sugars, including highly conserved and unique metabolic adaptations not described in mammals. Carbohydrate homeostasis is maintained by a network comprising intracellular energy sensors, transcriptional regulators, and hormonal and neuronal mechanisms that together coordinate animal behavior, gut function, and metabolic flux. Here we give an overview of the physiological responses associated with sugar intake and discuss some of the emerging themes and applications of the Drosophila model in understanding sugar sensing and carbohydrate metabolism.
Collapse
Affiliation(s)
- Wen-Bin Alfred Chng
- Global Health Institute, School of Life Sciences, EPFL, Station 19, 1015 Lausanne, Switzerland.
| | - Ville Hietakangas
- Department of Biosciences, University of Helsinki, 00790 Helsinki, Finland; Institute of Biotechnology, University of Helsinki, 00790 Helsinki, Finland
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, EPFL, Station 19, 1015 Lausanne, Switzerland.
| |
Collapse
|
44
|
Lin WY, Williams CR, Yan C, Parrish JZ. Functions of the SLC36 transporter Pathetic in growth control. Fly (Austin) 2016; 9:99-106. [PMID: 26735916 DOI: 10.1080/19336934.2015.1129089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Neurons exhibit extreme diversity in size, but whether large neurons have specialized mechanisms to support their growth is largely unknown. Recently, we identified the SLC36 transporter Pathetic (Path) as a factor required for extreme dendrite growth in neurons. Path is broadly expressed, but only neurons with large dendrite arbors or small neurons that are forced to grow large require path for their growth. To gain insight into the basis of growth control by path, we generated additional alleles of path and further examined the apparent specificity of growth defects in path mutants. Here, we confirm our prior finding that loss of path function imposes an upper limit on neuron growth, and additionally report that path likely limits overall neurite length rather than dendrite length alone. Using a GFP knock-in allele of path, we identify additional tissues where path likely functions in nutrient sensing and possibly growth control. Finally, we demonstrate that path regulates translational capacity in a cell type that does not normally require path for growth, suggesting that path may confer robustness on growth programs by buffering translational output. Altogether, these studies suggest that Path is a nutrient sensor with widespread function in Drosophila.
Collapse
Affiliation(s)
- Wen-Yang Lin
- a Department of Biology ; University of Washington ; Seattle , WA USA
| | - Claire R Williams
- a Department of Biology ; University of Washington ; Seattle , WA USA
| | - Connie Yan
- a Department of Biology ; University of Washington ; Seattle , WA USA
| | - Jay Z Parrish
- a Department of Biology ; University of Washington ; Seattle , WA USA
| |
Collapse
|
45
|
A microfluidics-based method for measuring neuronal activity in Drosophila chemosensory neurons. Nat Protoc 2016; 11:2389-2400. [PMID: 27809317 DOI: 10.1038/nprot.2016.144] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Monitoring neuronal responses to defined sensory stimuli is a powerful and widely used approach for understanding sensory coding in the nervous system. However, providing precise, stereotypic and reproducible cues while concomitantly recording neuronal activity remains technically challenging. Here we describe the fabrication and use of a microfluidics system that allows precise temporally restricted stimulation of Drosophila chemosensory neurons with an array of different chemical cues. The system can easily be combined with genetically encoded calcium sensors, and it can measure neuronal activity at single-cell resolution in larval sense organs and in the proboscis or leg of the adult fly. We describe the design of the master mold, the production of the microfluidic chip and live imaging using the calcium sensor GCaMP, expressed in distinct types of Drosophila chemosensory neurons. Fabrication of the master mold and microfluidic chips requires basic skills in photolithography and takes ∼2 weeks; the same devices can be used repeatedly over several months. Flies can be prepared for measurements in minutes and imaged for up to 1 h.
Collapse
|
46
|
Apostolopoulou AA, Köhn S, Stehle B, Lutz M, Wüst A, Mazija L, Rist A, Galizia CG, Lüdke A, Thum AS. Caffeine Taste Signaling in Drosophila Larvae. Front Cell Neurosci 2016; 10:193. [PMID: 27555807 PMCID: PMC4977282 DOI: 10.3389/fncel.2016.00193] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 07/19/2016] [Indexed: 11/13/2022] Open
Abstract
The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal, and ventral organ). However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative co-receptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s). This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviors.
Collapse
Affiliation(s)
- Anthi A Apostolopoulou
- Department of Biology, University of KonstanzKonstanz, Germany; Department of Biomedical Science, University of SheffieldSheffield, UK
| | - Saskia Köhn
- Department of Biology, University of Konstanz Konstanz, Germany
| | - Bernhard Stehle
- Department of Biology, University of Konstanz Konstanz, Germany
| | - Michael Lutz
- Department of Biology, University of Konstanz Konstanz, Germany
| | - Alexander Wüst
- Department of Biology, University of Konstanz Konstanz, Germany
| | - Lorena Mazija
- Department of Biology, University of Konstanz Konstanz, Germany
| | - Anna Rist
- Department of Biology, University of Konstanz Konstanz, Germany
| | - C Giovanni Galizia
- Department of Biology, University of KonstanzKonstanz, Germany; Zukunftskolleg, University of KonstanzKonstanz, Germany
| | - Alja Lüdke
- Department of Biology, University of KonstanzKonstanz, Germany; Zukunftskolleg, University of KonstanzKonstanz, Germany
| | - Andreas S Thum
- Department of Biology, University of KonstanzKonstanz, Germany; Zukunftskolleg, University of KonstanzKonstanz, Germany
| |
Collapse
|
47
|
Mang D, Shu M, Tanaka S, Nagata S, Takada T, Endo H, Kikuta S, Tabunoki H, Iwabuchi K, Sato R. Expression of the fructose receptor BmGr9 and its involvement in the promotion of feeding, suggested by its co-expression with neuropeptide F1 in Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 75:58-69. [PMID: 27288056 DOI: 10.1016/j.ibmb.2016.06.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 05/20/2016] [Accepted: 06/06/2016] [Indexed: 06/06/2023]
Abstract
Insect gustatory receptors (Grs) are members of a large family of proteins with seven transmembrane domains that provide insects with the ability to detect chemical signals critical for feeding, mating, and oviposition. To date, 69 Bombyx mori Grs (BmGrs) genes have been identified via genome studies. BmGr9 has been shown to respond specifically to fructose and to function as a ligand-gated ion channel selectively activated by fructose. However, the sites where this Gr are expressed remain unclear. We demonstrated using reverse transcription (RT)-PCR that BmGr9 is widely expressed in the central nervous system (CNS), as well as oral sensory organs. Additionally, immunohistochemistry was performed using anti-BmGr9 antiserum to show that BmGr9 is expressed in cells of the oral sensory organs, including the maxillary galea, maxillary palps, labrum, and labium, as well as in putative neurosecretory cells of the CNS. Furthermore, double immunohistochemical analysis showed that most BmGr9-expressing cells co-localized with putative neuropeptide F1-expressing cells in the brain, suggesting that BmGr9 is involved in the promotion of feeding behaviors. In addition, a portion of BmGr9-expressing cells in the brain co-localized with cells expressing BmGr6, a molecule of the sugar receptor clade, suggesting that sugars other than fructose are involved in the regulation of feeding behaviors in B. mori larvae.
Collapse
Affiliation(s)
- Dingze Mang
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan
| | - Min Shu
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan
| | - Shiho Tanaka
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan
| | - Shinji Nagata
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tomoyuki Takada
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan
| | - Haruka Endo
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan
| | - Shingo Kikuta
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan
| | - Hiroko Tabunoki
- Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, Tokyo 183-8509, Japan
| | - Kikuo Iwabuchi
- Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, Tokyo 183-8509, Japan
| | - Ryoichi Sato
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan.
| |
Collapse
|
48
|
Choi J, van Giesen L, Choi MS, Kang K, Sprecher SG, Kwon JY. A Pair of Pharyngeal Gustatory Receptor Neurons Regulates Caffeine-Dependent Ingestion in Drosophila Larvae. Front Cell Neurosci 2016; 10:181. [PMID: 27486388 PMCID: PMC4949222 DOI: 10.3389/fncel.2016.00181] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 07/06/2016] [Indexed: 12/16/2022] Open
Abstract
The sense of taste is an essential chemosensory modality that enables animals to identify appropriate food sources and control feeding behavior. In particular, the recognition of bitter taste prevents animals from feeding on harmful substances. Feeding is a complex behavior comprised of multiple steps, and food quality is continuously assessed. We here examined the role of pharyngeal gustatory organs in ingestion behavior. As a first step, we constructed a gustatory receptor-to-neuron map of the larval pharyngeal sense organs, and examined corresponding gustatory receptor neuron (GRN) projections in the larval brain. Out of 22 candidate bitter compounds, we found 14 bitter compounds that elicit inhibition of ingestion in a dose-dependent manner. We provide evidence that certain pharyngeal GRNs are necessary and sufficient for the ingestion response of larvae to caffeine. Additionally, we show that a specific pair of pharyngeal GRNs, DP1, responds to caffeine by calcium imaging. In this study we show that a specific pair of GRNs in the pharyngeal sense organs coordinates caffeine sensing with regulation of behavioral responses such as ingestion. Our results indicate that in Drosophila larvae, the pharyngeal GRNs have a major role in sensing food palatability to regulate ingestion behavior. The pharyngeal sense organs are prime candidates to influence ingestion due to their position in the pharynx, and they may act as first level sensors of ingested food.
Collapse
Affiliation(s)
- Jaekyun Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon South Korea
| | - Lena van Giesen
- Department of Biology, Institute of Zoology, University of Fribourg, Fribourg Switzerland
| | - Min Sung Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon South Korea
| | - KyeongJin Kang
- Department of Anatomy and Cell Biology, Samsung Biomedical Research Institute, School of Medicine, Sungkyunkwan University, Suwon South Korea
| | - Simon G Sprecher
- Department of Biology, Institute of Zoology, University of Fribourg, Fribourg Switzerland
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon South Korea
| |
Collapse
|
49
|
Macharia R, Mireji P, Murungi E, Murilla G, Christoffels A, Aksoy S, Masiga D. Genome-Wide Comparative Analysis of Chemosensory Gene Families in Five Tsetse Fly Species. PLoS Negl Trop Dis 2016; 10:e0004421. [PMID: 26886411 PMCID: PMC4757090 DOI: 10.1371/journal.pntd.0004421] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/11/2016] [Indexed: 12/04/2022] Open
Abstract
For decades, odour-baited traps have been used for control of tsetse flies (Diptera; Glossinidae), vectors of African trypanosomes. However, differential responses to known attractants have been reported in different Glossina species, hindering establishment of a universal vector control tool. Availability of full genome sequences of five Glossina species offers an opportunity to compare their chemosensory repertoire and enhance our understanding of their biology in relation to chemosensation. Here, we identified and annotated the major chemosensory gene families in Glossina. We identified a total of 118, 115, 124, and 123 chemosensory genes in Glossina austeni, G. brevipalpis, G. f. fuscipes, G. pallidipes, respectively, relative to 127 reported in G. m. morsitans. Our results show that tsetse fly genomes have fewer chemosensory genes when compared to other dipterans such as Musca domestica (n>393), Drosophila melanogaster (n = 246) and Anopheles gambiae (n>247). We also found that Glossina chemosensory genes are dispersed across distantly located scaffolds in their respective genomes, in contrast to other insects like D. melanogaster whose genes occur in clusters. Further, Glossina appears to be devoid of sugar receptors and to have expanded CO2 associated receptors, potentially reflecting Glossina's obligate hematophagy and the need to detect hosts that may be out of sight. We also identified, in all species, homologs of Ir84a; a Drosophila-specific ionotropic receptor that promotes male courtship suggesting that this is a conserved trait in tsetse flies. Notably, our selection analysis revealed that a total of four gene loci (Gr21a, GluRIIA, Gr28b, and Obp83a) were under positive selection, which confers fitness advantage to species. These findings provide a platform for studies to further define the language of communication of tsetse with their environment, and influence development of novel approaches for control. Chemical sensing is crucial to survival of tsetse flies; the sole cyclical vectors of African trypanosomes that cause the neglected zoonotic tropical disease sleeping sickness in humans. For many years, vector control has been used to mitigate trypanosome infections among rural populations of sub-Saharan Africa. Nevertheless, development of an all-inclusive strategy to control tsetse flies using odour-baited traps has been limited by disparate responses to the odors exhibited by various tsetse species. In this study, proteins that are putatively involved in chemical sensing were identified and compared among five tsetse species and their close relatives with an aim of enhancing our knowledge on tsetse olfaction. Our findings suggest that the chemosensory genes are conserved across tsetse fly species despite their documented differential responses in odours. We found no species-specific sequence variations among the five species to suggest that differential response to odours is due to loss or gain of genes. It could therefore be hypothesized that the observed differences emerge during the downstream processing of odour molecules involving post translational modification of the chemosensory proteins. We thus recommend functional studies on the identified proteins to determine their roles and molecular interactions.
Collapse
Affiliation(s)
- Rosaline Macharia
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- South African National Bioinformatics Institute, University of the Western Cape, Cape Town, South Africa
| | - Paul Mireji
- Department of Epidemiology of Microbial Diseases, Yale School of Public Heath, New Haven, Connecticut, United States of America
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- * E-mail: (PM); (DM)
| | - Edwin Murungi
- Department of Biochemistry and Molecular Biology, Egerton University, Njoro, Kenya
| | - Grace Murilla
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Alan Christoffels
- South African National Bioinformatics Institute, University of the Western Cape, Cape Town, South Africa
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Heath, New Haven, Connecticut, United States of America
| | - Daniel Masiga
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- * E-mail: (PM); (DM)
| |
Collapse
|
50
|
van Giesen L, Hernandez-Nunez L, Delasoie-Baranek S, Colombo M, Renaud P, Bruggmann R, Benton R, Samuel ADT, Sprecher SG. Multimodal stimulus coding by a gustatory sensory neuron in Drosophila larvae. Nat Commun 2016; 7:10687. [PMID: 26864722 PMCID: PMC4753250 DOI: 10.1038/ncomms10687] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 01/11/2016] [Indexed: 11/30/2022] Open
Abstract
Accurate perception of taste information is crucial for animal survival. In adult Drosophila, gustatory receptor neurons (GRNs) perceive chemical stimuli of one specific gustatory modality associated with a stereotyped behavioural response, such as aversion or attraction. We show that GRNs of Drosophila larvae employ a surprisingly different mode of gustatory information coding. Using a novel method for calcium imaging in the larval gustatory system, we identify a multimodal GRN that responds to chemicals of different taste modalities with opposing valence, such as sweet sucrose and bitter denatonium, reliant on different sensory receptors. This multimodal neuron is essential for bitter compound avoidance, and its artificial activation is sufficient to mediate aversion. However, the neuron is also essential for the integration of taste blends. Our findings support a model for taste coding in larvae, in which distinct receptor proteins mediate different responses within the same, multimodal GRN. While gustatory systems have been extensively studied in adult Drosophila, not much is known about taste coding at the larval stage. Here, the authors investigate gustatory receptor neurons in larvae and find single neurons are capable of responding to more than one taste modality.
Collapse
Affiliation(s)
- Lena van Giesen
- Department of Biology, Institute of Zoology, University of Fribourg, Chemin du Musee 10, Fribourg CH-1700, Switzerland
| | - Luis Hernandez-Nunez
- Center for Brain Science and Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Sophie Delasoie-Baranek
- Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Martino Colombo
- Faculty of Biology and Medicine, Center for Integrative Genomics, University of Lausanne, Genopode Building, Lausanne CH-1015, Switzerland
| | - Philippe Renaud
- Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Rémy Bruggmann
- Faculty of Biology and Medicine, Center for Integrative Genomics, University of Lausanne, Genopode Building, Lausanne CH-1015, Switzerland
| | - Richard Benton
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Berne, Berne 3012, Switzerland
| | - Aravinthan D T Samuel
- Center for Brain Science and Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Simon G Sprecher
- Department of Biology, Institute of Zoology, University of Fribourg, Chemin du Musee 10, Fribourg CH-1700, Switzerland
| |
Collapse
|