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Richards SL, Sousan S, Murray W, White A, Peyton K, Slade R. Development of novel compact wind tunnel for testing efficacy of insecticide formulated products in mosquitoes. PEST MANAGEMENT SCIENCE 2024; 80:3140-3148. [PMID: 38345320 DOI: 10.1002/ps.8018] [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: 10/10/2023] [Revised: 01/04/2024] [Accepted: 02/08/2024] [Indexed: 02/22/2024]
Abstract
BACKGROUND Ultra-low volume (ULV) space sprays aerosolize insecticide formulated products (FP) to contact flying mosquitoes, while barrier sprays expose mosquitoes to FP residue on vegetation and other surfaces. Centers for Disease Control and Prevention bottle bioassays used to assess insecticide resistance are based on residual active ingredient (AI) exposure and do not directly relate to FP efficacy. The current pilot study developed a novel compact wind tunnel for mosquito exposure to FP. Caged Aedes albopictus and Culex pipiens/quinquefasciatus were exposed to undiluted Biomist®3 + 15 FP (permethrin AI) or air (control) within the wind tunnel, transferred to new cages, and held in a 28 °C incubator. Separate mosquitoes were exposed to residual permethrin AI (8 μg mL-1) in bottle bioassays. Mortality was monitored 15, 30, 60, and 120 min post-exposure. RESULTS Chi-square tests (P < 0.05) showed significantly higher mortality in Aedes compared to Culex populations for most time points in both bioassay and wind tunnel exposure groups. As expected, mosquitoes exposed to Biomist®3 + 15 showed higher mortality rates than bottle bioassay exposure to permethrin. Two Culex colonies resistant to permethrin in bottle bioassays were susceptible to Biomist®3 + 15 in the wind tunnel. CONCLUSION The novel compact wind tunnel developed here may be an alternative to field trials for testing FP efficacy, avoiding factors such as weather, logistical planning, and extended personnel hours. The wind tunnel could allow programs to conveniently test efficacy of multiple FP. Comparisons of different insecticide exposure methods provide practical information to inform operational decisions. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Stephanie L Richards
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
| | - Sinan Sousan
- Department of Public Health, Brody School of Medicine, East Carolina University, Greenville, NC, USA
- North Carolina Agromedicine Institute, East Carolina University, Greenville, NC, USA
| | - Will Murray
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
- Department of Public Health, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Avian White
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
| | - Kaya Peyton
- College of Health and Sciences, Department of Environmental, Earth, and Geospatial Science, North Carolina Central University, Durham, NC, USA
| | - Raven Slade
- Department of Health Education and Promotion, Environmental Health Science Program, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
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Holmes CJ, Chakraborty S, Ajayi OM, Uhran MR, Frigard R, Stacey CL, Susanto EE, Chen SC, Rasgon JL, DeGennaro MJ, Xiao Y, Benoit JB. Multiple bouts of blood feeding in mosquitoes allow for prolonged survival and are predicted to increase viral transmission during drought. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.595907. [PMID: 38854138 PMCID: PMC11160655 DOI: 10.1101/2024.05.28.595907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Survival through periods of drought is critical for mosquitoes to reside in semi-arid regions with humans, but water sources may be limited. Previous studies have shown that dehydrated mosquitoes will increase blood feeding propensity, but how this would occur over extended dry periods is unknown. Following a bloodmeal, prolonged exposure to dry conditions increased secondary blood feeding in mosquitoes by nearly two-fold, and chronic blood feeding allowed mosquitoes to survive twenty days without access to water sources. This refeeding did not alter the number of eggs generated, suggesting this refeeding is for hydration and nutrient replenishment. Exposure to desiccating conditions following a bloodmeal resulted in increased activity, decreased sleep levels, and prompted a return of CO 2 sensing before egg deposition. The increased blood feeding during the vitellogenic stage and higher survival during dry periods are predicted to increase pathogen transmission and explain the elevated levels of specific arbovirus cases during dry conditions. These results solidify our understanding of the role of dry periods on mosquito blood feeding and how mosquito dehydration contributes to vectorial capacity and disease transmission dynamics.
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Li JQ, Chen YW, Wang Q, Yin MZ, Ma S, Liu Q, Sun XY, Zhang WJ, Yang YY, Mang DZ, Zhu XY, Sun L, Zhang YN. Gustatory Receptor 206 Participates in the Foraging Behavior of Larvae of Polyphagous Pest Spodoptera litura. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:12003-12013. [PMID: 38748811 DOI: 10.1021/acs.jafc.4c01434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Insect gustatory receptors (GRs) aid in the precise identification of deterrent or stimulant compounds associated with food, mating, and egg-laying. Thus, they are promising targets for developing efficient insecticides. Here, 61 GRs in the chemosensory organs of Spodoptera litura larvae and adults were identified. Among them, SlitGR206 exhibited larval labium (LL)-specific expression characteristics. To explore the role of SlitGR206, a bacterial expression system was established to produce high-quality double-stranded RNA (dsRNA) and suppress SlitGR206 expression in LL. Subsequent behavioral assessments revealed that SlitGR206 silencing influenced larval feeding preferences and absorption. Moreover, it was found to reduce the ability of larvae to forage the five crucial host odorants. These findings demonstrate that SlitGR206 likely plays an indirect regulatory role in host recognition, consequently affecting foraging behavior. This provides a crucial foundation for the analysis of functional diversity among insect GRs and the precise development of nucleic acid pesticides in the future.
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Affiliation(s)
- Jian-Qiao Li
- Anhui Engineering Research Center for Green Production Technology of Drought Grain Crops, College of Life Sciences, Huaibei Normal University, Huaibei 235000, China
| | - Yu-Wen Chen
- Anhui Engineering Research Center for Green Production Technology of Drought Grain Crops, College of Life Sciences, Huaibei Normal University, Huaibei 235000, China
| | - Qian Wang
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China
- The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou311300,China
| | - Mao-Zhu Yin
- Suzhou Academy of Agricultural Sciences, Suzhou 234000, China
| | - Sai Ma
- Anhui Engineering Research Center for Green Production Technology of Drought Grain Crops, College of Life Sciences, Huaibei Normal University, Huaibei 235000, China
| | - Qiang Liu
- Anhui Engineering Research Center for Green Production Technology of Drought Grain Crops, College of Life Sciences, Huaibei Normal University, Huaibei 235000, China
| | - Xin-Yao Sun
- Anhui Engineering Research Center for Green Production Technology of Drought Grain Crops, College of Life Sciences, Huaibei Normal University, Huaibei 235000, China
| | - Wen-Jing Zhang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding 071002, China
| | - Yan-Yan Yang
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan
| | - Ding-Ze 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
| | - Xiu-Yun Zhu
- Anhui Engineering Research Center for Green Production Technology of Drought Grain Crops, College of Life Sciences, Huaibei Normal University, Huaibei 235000, China
| | - Liang Sun
- Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China
| | - Ya-Nan Zhang
- Anhui Engineering Research Center for Green Production Technology of Drought Grain Crops, College of Life Sciences, Huaibei Normal University, Huaibei 235000, China
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Liu Y, Zhang S, Cao S, Jacquin-Joly E, Zhou Q, Liu Y, Wang G. An odorant receptor mediates the avoidance of Plutella xylostella against parasitoid. BMC Biol 2024; 22:61. [PMID: 38475722 DOI: 10.1186/s12915-024-01862-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 03/06/2024] [Indexed: 03/14/2024] Open
Abstract
BACKGROUND Ecosystems are brimming with myriad compounds, including some at very low concentrations that are indispensable for insect survival and reproduction. Screening strategies for identifying active compounds are typically based on bioassay-guided approaches. RESULTS Here, we selected two candidate odorant receptors from a major pest of cruciferous plants-the diamondback moth Plutella xylostella-as targets to screen for active semiochemicals. One of these ORs, PxylOR16, exhibited a specific, sensitive response to heptanal, with both larvae and adult P. xylostella displaying heptanal avoidance behavior. Gene knockout studies based on CRISPR/Cas9 experimentally confirmed that PxylOR16 mediates this avoidance. Intriguingly, rather than being involved in P. xylostella-host plant interaction, we discovered that P. xylostella recognizes heptanal from the cuticular volatiles of the parasitoid wasp Cotesia vestalis, possibly to avoid parasitization. CONCLUSIONS Our study thus showcases how the deorphanization of odorant receptors can drive discoveries about their complex functions in mediating insect survival. We also demonstrate that the use of odorant receptors as a screening platform could be efficient in identifying new behavioral regulators for application in pest management.
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Affiliation(s)
- Yipeng Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, China
| | - Sai Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Song Cao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Emmanuelle Jacquin-Joly
- Institute of Ecology and Environmental Sciences of Paris, INRAE, Sorbonne Université, CNRS, UPEC, UniversitéParis Cité, 78026, Versailles, IRD, France
| | - Qiong Zhou
- College of Life Sciences, Hunan Normal University, Changsha, 410006, China
| | - Yang Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Guirong Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China.
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5
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Ziemba PM, Mueck A, Gisselmann G, Stoertkuhl KF. Functional expression and ligand identification of homo- and heteromeric Drosophila melanogaster CO2 receptors in the Xenopus laevis oocyte system. PLoS One 2023; 18:e0295404. [PMID: 38157355 PMCID: PMC10756536 DOI: 10.1371/journal.pone.0295404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/20/2023] [Indexed: 01/03/2024] Open
Abstract
Carbon dioxide (CO2) is an important olfactory cue in Drosophila melanogaster and can elicit both attractive and aversive behaviors. It is detected by gustatory receptors, Gr21a and Gr63a, found in the ab1C neuron in basiconic sensilla on the third antennal segment. Volatile substances that modulate the receptors' function are of interest for pest control. While several substances block ab1C neurons or mimic the activating effect of carbon dioxide, it is not known if these substances are indeed ligands of the CO2 receptor or might act on other proteins in the receptor neuron. In this study, we used the recombinant Xenopus laevis expression system and two-electrode voltage-clamp technology to investigate the receptor function. We found that application of sodium bicarbonate evokes large inward currents in oocytes co-expressing Gr21a and Gr63a. The receptors most likely form hetromultimeric complexes. Homomultimeric receptors of Gr21a or Gr63a are sufficient for receptor functionality, although oocytes gave significantly lower current responses compared to the probable heteromultimeric receptor. We screened for putative blockers of the sodium bicarbonate response and confirmed that some of the substances identified by spike recordings of olfactory receptor neurons, such as 1-hexanol, are also blockers in the Xenopus oocyte system. We also identified a new blocking substance, citronellol, which is related to insect repellents. Many substances that activate receptor neurons were inactive in the Xenopus oocyte system, indicating that they may not be ligands for the receptor, but may act on other proteins. However, methyl pyruvate and n-hexylamine were found to be activators of the recombinant Gr21a/Gr63a receptor.
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Affiliation(s)
- Paul M. Ziemba
- AG Physiology of Senses, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Alina Mueck
- AG Physiology of Senses, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Günter Gisselmann
- Department of Cell Physiology, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Klemens F. Stoertkuhl
- AG Physiology of Senses, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
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Singh P, Goyal S, Gupta S, Garg S, Tiwari A, Rajput V, Bates AS, Gupta AK, Gupta N. Combinatorial encoding of odors in the mosquito antennal lobe. Nat Commun 2023; 14:3539. [PMID: 37322224 PMCID: PMC10272161 DOI: 10.1038/s41467-023-39303-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 06/06/2023] [Indexed: 06/17/2023] Open
Abstract
Among the cues that a mosquito uses to find a host for blood-feeding, the smell of the host plays an important role. Previous studies have shown that host odors contain hundreds of chemical odorants, which are detected by different receptors on the peripheral sensory organs of mosquitoes. But how individual odorants are encoded by downstream neurons in the mosquito brain is not known. We developed an in vivo preparation for patch-clamp electrophysiology to record from projection neurons and local neurons in the antennal lobe of Aedes aegypti. Combining intracellular recordings with dye-fills, morphological reconstructions, and immunohistochemistry, we identify different sub-classes of antennal lobe neurons and their putative interactions. Our recordings show that an odorant can activate multiple neurons innervating different glomeruli, and that the stimulus identity and its behavioral preference are represented in the population activity of the projection neurons. Our results provide a detailed description of the second-order olfactory neurons in the central nervous system of mosquitoes and lay a foundation for understanding the neural basis of their olfactory behaviors.
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Affiliation(s)
- Pranjul Singh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Shefali Goyal
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Smith Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Sanket Garg
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
- Department of Economic Sciences, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Abhinav Tiwari
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Varad Rajput
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Alexander Shakeel Bates
- Department of Neurobiology and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Arjit Kant Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Nitin Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.
- Mehta Family Center for Engineering in Medicine, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.
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7
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Boronat-Garcia A, Iben J, Dominguez-Martin E, Stopfer M. Identification and analysis of odorant receptors expressed in the two main olfactory organs, antennae and palps, of Schistocerca americana. Sci Rep 2022; 12:22628. [PMID: 36587060 PMCID: PMC9805433 DOI: 10.1038/s41598-022-27199-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 12/28/2022] [Indexed: 01/01/2023] Open
Abstract
Locusts depend upon their sense of smell and provide useful models for understanding olfaction. Extending this understanding requires knowledge of the molecular and structural organization of the olfactory system. Odor sensing begins with olfactory receptor neurons (ORNs), which express odorant receptors (ORs). In insects, ORNs are housed, in varying numbers, in olfactory sensilla. Because the organization of ORs within sensilla affects their function, it is essential to identify the ORs they contain. Here, using RNA sequencing, we identified 179 putative ORs in the transcriptomes of the two main olfactory organs, antenna and palp, of the locust Schistocerca americana. Quantitative expression analysis showed most putative ORs (140) are expressed in antennae while only 31 are in the palps. Further, our analysis identified one OR detected only in the palps and seven ORs that are expressed differentially by sex. An in situ analysis of OR expression suggested ORs are organized in non-random combinations within antennal sensilla. A phylogenetic comparison of OR predicted protein sequences revealed homologous relationships among two other Acrididae species. Our results provide a foundation for understanding the organization of the first stage of the olfactory system in S. americana, a well-studied model for olfactory processing.
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Affiliation(s)
- Alejandra Boronat-Garcia
- grid.420089.70000 0000 9635 8082Section on Sensory Coding and Neural Ensembles, National Institutes of Health, Eunice Kennedy Shriver National Institute of Child and Human Development, Bethesda, MD USA
| | - James Iben
- grid.420089.70000 0000 9635 8082Molecular and Genomics Core, National Institutes of Health, Eunice Kennedy Shriver National Institute of Child and Human Development, Bethesda, MD USA
| | - Eunice Dominguez-Martin
- grid.416870.c0000 0001 2177 357XBiochemistry Section, National Institutes of Health, National Institute of Neurological Disorders and Stroke, Bethesda, MD USA
| | - Mark Stopfer
- grid.420089.70000 0000 9635 8082Section on Sensory Coding and Neural Ensembles, National Institutes of Health, Eunice Kennedy Shriver National Institute of Child and Human Development, Bethesda, MD USA
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8
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Compounds from human odor induce attraction and landing in female yellow fever mosquitoes (Aedes aegypti). Sci Rep 2022; 12:15638. [PMID: 36130984 PMCID: PMC9492692 DOI: 10.1038/s41598-022-19254-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/26/2022] [Indexed: 11/09/2022] Open
Abstract
The female Aedes aegypti mosquito is a vector of many human diseases such as yellow fever, dengue, and Zika. Transmission of these viruses occurs when an infected female mosquito locates a suitable human host, alights, and blood feeds. Aedes aegypti use human-emitted odors, as well as heat and visual cues, for host location. However, none of the previously identified human-produced compounds induce significant orientation and landing on a human host. Here we show that female yellow fever mosquitoes orient to and land on a mixture of compounds identified from human skin rubbings. Using odor collection, extraction, a two-choice, bioassay-guided fractionation, and chemical analysis, we identified mixtures of 2-ketoglutaric acid and L-lactic acid as landing attractants for female Ae. aegypti. The mixture of pyruvic acid and L-lactic acid were also found to be weakly attractive. Using ratio-response assays, we found that the attraction and alighting behaviors of the mosquitoes were directly related to the ratio of these compounds presented on the surface of the glass assay beads, suggesting that these compounds could mediate landing on a human host even at sub-nanogram dosages. The newly identified compounds fill a gap in our knowledge of odor-mediated attraction of Ae. aegypti and may lead to the development of new attractant-based mosquito control tactics.
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9
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Kong D, Shi D, Wang C, Zhai R, Lyu L, He Y, Wang D. Identification and Validation of Reference Genes for Expression Analysis Using qRT-PCR in Cimex hemipterus (Hemiptera: Cimicidae). INSECTS 2022; 13:784. [PMID: 36135485 PMCID: PMC9502763 DOI: 10.3390/insects13090784] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/23/2022] [Accepted: 08/26/2022] [Indexed: 06/16/2023]
Abstract
The tropical bed bug, Cimex hemipterus (F.) (Hemiptera: Cimicidae) is an important public-health pest that feeds on the blood of humans and some other animals. To explore the function of the target genes of C. hemipterus, it is essential to select suitable reference genes for the accurate quantification of gene expression. Here, we selected 10 frequently used reference genes in insects and evaluated their stability in C. hemipterus under various biotic (developmental stage, sex, and tissue) and abiotic (gas stimulation and temperature) conditions through RefFinder (which integrates four computational programs: geNorm, NormFinder, BestKeeper, and ∆Ct). Results indicate that the optimal combination of reference genes for each experimental condition was as follows: RPL8 and EF1α for the developmental stage (eggs, early instar nymphs, late instar nymphs, and adults), RPL8 and RPS16 for adult sex, RPL8 and RPL11 for adult tissue (head, thorax, abdomen, and legs), RPL8 and β-tubulin for gas stimulation (air and carbon dioxide), and RPL8 and NADH for temperature (0, 5, 17, 30, and 37 °C). Finally, the expression pattern of the HSP70 and GR21 genes were analyzed, and the results highlight the importance of appropriate reference-gene selection. Our results provide a comprehensive list of optimal reference genes from C. hemipterus for the first time, which will contribute to accurately analyzing the expression of target genes.
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Affiliation(s)
- Delong Kong
- Department of Entomology, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, Guangzhou 510642, China
- Engineering Research Center of Biological Control, Ministry of Education, Guangzhou 510642, China
| | - Daxia Shi
- Department of Entomology, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, Guangzhou 510642, China
- Engineering Research Center of Biological Control, Ministry of Education, Guangzhou 510642, China
| | - Changlu Wang
- Department of Entomology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Ruyue Zhai
- Department of Entomology, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, Guangzhou 510642, China
- Engineering Research Center of Biological Control, Ministry of Education, Guangzhou 510642, China
| | - Lingling Lyu
- Ningbo Dayang Technology Co., Ltd., Ningbo 315000, China
| | - Yurong He
- Department of Entomology, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, Guangzhou 510642, China
- Engineering Research Center of Biological Control, Ministry of Education, Guangzhou 510642, China
| | - Desen Wang
- Department of Entomology, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, Guangzhou 510642, China
- Engineering Research Center of Biological Control, Ministry of Education, Guangzhou 510642, China
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10
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Herre M, Goldman OV, Lu TC, Caballero-Vidal G, Qi Y, Gilbert ZN, Gong Z, Morita T, Rahiel S, Ghaninia M, Ignell R, Matthews BJ, Li H, Vosshall LB, Younger MA. Non-canonical odor coding in the mosquito. Cell 2022; 185:3104-3123.e28. [PMID: 35985288 PMCID: PMC9480278 DOI: 10.1016/j.cell.2022.07.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/05/2022] [Accepted: 07/20/2022] [Indexed: 12/23/2022]
Abstract
Aedes aegypti mosquitoes are a persistent human foe, transmitting arboviruses including dengue when they feed on human blood. Mosquitoes are intensely attracted to body odor and carbon dioxide, which they detect using ionotropic chemosensory receptors encoded by three large multi-gene families. Genetic mutations that disrupt the olfactory system have modest effects on human attraction, suggesting redundancy in odor coding. The canonical view is that olfactory sensory neurons each express a single chemosensory receptor that defines its ligand selectivity. We discovered that Ae. aegypti uses a different organizational principle, with many neurons co-expressing multiple chemosensory receptor genes. In vivo electrophysiology demonstrates that the broad ligand-sensitivity of mosquito olfactory neurons depends on this non-canonical co-expression. The redundancy afforded by an olfactory system in which neurons co-express multiple chemosensory receptors may increase the robustness of the mosquito olfactory system and explain our long-standing inability to disrupt the detection of humans by mosquitoes. Humans produce a complex blend of odor cues that attract female mosquitoes, and these cues are typically detected by olfactory neurons expressing a single receptor. In female Aedes aegypti mosquitos, however, many of these neurons co-express multiple chemosensory receptors directly affecting mosquito behavior and challenging the canonical one-receptor-to-one-neuron organization.
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Affiliation(s)
- Margaret Herre
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA; Kavli Neural Systems Institute, New York, NY 10065, USA; Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - Olivia V Goldman
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA; Kavli Neural Systems Institute, New York, NY 10065, USA
| | - Tzu-Chiao Lu
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gabriela Caballero-Vidal
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 234 22, Sweden
| | - Yanyan Qi
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zachary N Gilbert
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Zhongyan Gong
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Takeshi Morita
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, New York, NY 10065, USA
| | - Saher Rahiel
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Majid Ghaninia
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 234 22, Sweden
| | - Rickard Ignell
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 234 22, Sweden
| | - Benjamin J Matthews
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, New York, NY 10065, USA
| | - Hongjie Li
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Leslie B Vosshall
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA; Kavli Neural Systems Institute, New York, NY 10065, USA; Howard Hughes Medical Institute, New York, NY 10065, USA
| | - Meg A Younger
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York, NY 10065, USA; Kavli Neural Systems Institute, New York, NY 10065, USA; Department of Biology, Boston University, Boston, MA 02215, USA.
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11
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Spanoudis CG, Wondwosen B, Isberg E, Andreadis SS, Kline DL, Birgersson G, Ignell R. The chemical code for attracting Culex mosquitoes. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.930665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mosquitoes use chemical codes to locate and discriminate among vertebrate hosts to obtain a blood meal. Recent advances have allowed for the identification of the chemical codes used by mosquitoes to locate and discriminate humans from other vertebrate hosts. Humans are incidental “dead-end” hosts for the West Nile virus, which is maintained in an enzootic cycle, primarily through its transmission between infected birds by Culex mosquitoes. Host-seeking Culex mosquitoes are attracted to the odor of chicken, which are used in sentinel traps to monitor West Nile virus transmission. Using combined gas chromatography and electroantennography and mass spectrometry we identify a blend of volatile organic compounds present in chicken emanates, including mostly salient bioactive compounds previously identified in human emanates. When released at their identified ratios, this blend elicits behavioral responses of Culex pipiens molestus and Culex quinquefasciatus similar to that to the natural chicken odor. Tested under field conditions, this blend attract Culex spp. and other species of mosquitoes using birds among their hosts. This study provides evidence for conserved chemical codes for resource location by mosquitoes, and highlights the intricate role of CO2 for host-seeking mosquitoes. The identification of conserved chemical codes, which drive innate preference behaviors that are fundamental for survival and reproduction, provides important substrates for future control interventions targeting disease vector mosquitoes.
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12
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Hernández-Fernández A, Torre IG. Compression principle and Zipf's Law of brevity in infochemical communication. Biol Lett 2022; 18:20220162. [PMID: 35892209 PMCID: PMC9326285 DOI: 10.1098/rsbl.2022.0162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Compression has been presented as a general principle of animal communication. Zipf's Law of brevity is a manifestation of this postulate and can be generalized as the tendency of more frequent communicative elements to be shorter. Previous works supported this claim, showing evidence of Zipf's Law of brevity in animal acoustical communication and human language. However, a significant part of the communicative effort in biological systems is carried out in other transmission channels, such as those based on infochemicals. To fill this gap, we seek, for the first time, evidence of this principle in infochemical communication by analysing the statistical tendency of more frequent infochemicals to be chemically shorter and lighter. We analyse data from the largest and most comprehensive open-access infochemical database known as Pherobase, recovering Zipf's Law of brevity in interspecific communication (allelochemicals) but not in intraspecific communication (pheromones). Moreover, these results are robust even when addressing different magnitudes of study or mathematical approaches. Therefore, different dynamics from the compression principle would dominate intraspecific chemical communication, defying the universality of Zipf's Law of brevity. To conclude, we discuss the exception found for pheromones in the light of other potential communicative paradigms such as pressures on successful communication or the Handicap principle.
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Affiliation(s)
- Antoni Hernández-Fernández
- Complexity and Quantitative Linguistics Lab, Institut de Ciències de l'Educació, Universitat Politècnica de Catalunya, Av. Doctor Marañón 44-50, Barcelona 08028, Catalonia, Spain
| | - Iván G Torre
- Language and Speech Laboratory, Universidad del País Vasco, Justo Vélez de Elorriaga Kalea, 1, 01006 Vitoria, Spain.,Departamento de Matemática Aplicada, Universidad Politécnica de Madrid, Avda. Puerta de Hierro, 2-4, 28040 Madrid, Spain
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13
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Xu P, Choo YM, Leal WS. Odorant inhibition in mosquito olfaction mediated by inverse agonists. Biochem Biophys Res Commun 2022; 609:156-162. [PMID: 35430419 PMCID: PMC10540603 DOI: 10.1016/j.bbrc.2022.04.015] [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: 02/22/2022] [Accepted: 04/05/2022] [Indexed: 11/02/2022]
Abstract
The insect repellent methyl salicylate elicits excitatory responses upon interaction with CquiOR32, an odorant receptor (OR) from the southern house mosquito, Culex quinquefasciatus. By contrast, eucalyptol binds to CquiOR32 to generate electrophysiological and behavioral inhibitory responses. In an attempt to identify CquiOR32 variants displaying more robust inhibitory responses for more accurate current-voltage analysis, we sequenced 31 CquiOR32 clones. In the Xenopus oocyte recording system, CquiOR32V2/CquiOrco-expressing oocytes yielded eucalyptol-elicited outward (inhibitory) currents relatively larger than methyl salicylate-generated inward (excitatory) currents. Rescuing experiments showed that two of the amino acid substitutions in CquiOR32V2 located in a predicted transmembrane helix of the receptor are determinants of the outward/inward ratios. These findings, along with co-stimulus assays, suggest that odorant and inhibitor may bind to the same binding pocket. Current-voltage relationships obtained with standard perfusion buffer and those devoid of Na+ or Cl- indicated that both excitatory and inhibitory currents are mediated, at least in part, by cation. We then concluded that eucalyptol is an inverse agonist, which shifts the open ⇔ closed equilibrium of the receptor toward the closed conformation, thus reducing the spontaneous activity. By contrast, the binding of methyl salicylate shifts the equilibrium towards the open conformation and, consequently, leads to an increase in cation influx.
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Affiliation(s)
- Pingxi Xu
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA
| | - Young-Moo Choo
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA
| | - Walter S Leal
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA.
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14
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Xu P, Choo YM, An S, Leal GM, Leal WS. Mosquito odorant receptor sensitive to natural spatial repellents and inhibitory compounds. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 144:103763. [PMID: 35364281 PMCID: PMC10540633 DOI: 10.1016/j.ibmb.2022.103763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/17/2022] [Accepted: 03/27/2022] [Indexed: 06/14/2023]
Abstract
Previously, we have identified an odorant receptor (OR) from the southern house mosquito Culex quinquefasciatus, CquiOR32, which responded to both odorants (agonists) and inhibitory compounds (antagonists). CquiOR32/CquiOrco-expressing oocytes responded to methyl salicylate and other odorants with inward (regular) currents but gave currents in the reverse direction when challenged with eucalyptol and other inhibitors. To determine whether hitherto unknown ORs show this intrareceptor inhibition, we have now examined two other receptors in the same cluster, CquiOR27 and CquiOR28. We cloned and tested four variants of CquiOR28, but none of the 250 compounds in our panel of odorants, including an Orco ligand candidate (OLC12), elicited inward or upward deflections of the current traces. By contrast, CquiOR27/CquiOrco-expressing oocytes gave robust, dose-dependent inward currents when challenged with γ-octalactone and other odorants. On the other hand, octylamine and other phenolic compounds elicited dose-dependent currents in the reverse direction. When stimulatory and inhibitory compounds were presented in binary mixtures, γ-octalactone-elicited inward currents were attenuated in a dose-dependent manner according to the concentration of octylamine. As part of our chemical ecology approach, we tested the repellency activity of the most potent ligands in the surface landing and feeding assay and a newly reported hand-in cage assay. Protection elicited by γ-octalactone did not differ significantly from that of DEET at the same dose. In the hand-in cage assay, a cream formulation of γ-octalactone showed 97.0 ± 1.3% protection, with 47.6 ± 8.3% and 1.4 ± 0.7% landings per trial in the hands covered with a control and γ-octalactone cream, respectively (N = 8, p = 0.0078, Wilcoxon matched-pairs signed-rank test).
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Affiliation(s)
- Pingxi Xu
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA
| | - Young-Moo Choo
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA
| | - Sunny An
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA
| | - Gabriel M Leal
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA
| | - Walter S Leal
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA, 95616, USA.
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15
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Coutinho-Abreu IV, Riffell JA, Akbari OS. Human attractive cues and mosquito host-seeking behavior. Trends Parasitol 2022; 38:246-264. [PMID: 34674963 PMCID: PMC10789295 DOI: 10.1016/j.pt.2021.09.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 12/29/2022]
Abstract
Female mosquitoes use chemical and physical cues, including vision, smell, heat, and humidity, to orient toward hosts. Body odors are produced by skin resident bacteria that convert metabolites secreted in sweat into odorants that confer the characteristic body scent. Mosquitoes detect these compounds using olfactory receptors in their antennal olfactory receptor neurons. Such information is further integrated with the senses of temperature and humidity, as well as vision, processed in the brain into a behavioral output, leading to host finding. Knowledge of human scent components unveils a variety of odorants that are attractive to mosquitoes, but also odor-triggering repellency. Finding ways to divert human-seeking behavior by female mosquitoes using odorants can possibly mitigate mosquito-borne pathogen transmission.
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Affiliation(s)
- Iliano V Coutinho-Abreu
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jeffrey A Riffell
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Omar S Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA.
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16
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Studies on the Volatiles Composition of Stored Sheep Wool, and Attractancy toward Aedes aegypti Mosquitoes. INSECTS 2022; 13:insects13020208. [PMID: 35206782 PMCID: PMC8879698 DOI: 10.3390/insects13020208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/13/2022] [Accepted: 02/16/2022] [Indexed: 02/05/2023]
Abstract
To discover new natural materials for insect management, commercially available stored sheep wool was investigated for attractancy to female adult Aedes aegypti mosquitoes. The volatiles from sheep wool were collected by various techniques of headspace (HS) extractions and hydrodistillation. These extracts were analyzed using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) coupled with GC-MS. Fifty-two volatile compounds were detected, many of them known for their mosquito attractant activity. Seven compounds were not previously reported in sheep products. The volatile composition of the extracts varied significantly across collections, depending on the extraction techniques or types of fibers applied. Two types of bioassay were conducted to study attractancy of the sheep wool volatiles to mosquitoes: laboratory bioassays using glass tubes, and semi-field bioassays using large, screened outdoor cages. In bioassays with glass tubes, the sheep wool hydrodistillate and its main component, thialdine, did not show any significant attractant activity against female adult Ae. aegypti mosquitoes. Semi-field bioassays in two large screened outdoor cages, each equipped with a U.S. Centers for Disease Control (CDC) trap and the various bait setups with Vortex apparatus, revealed that vibrating wool improved mosquito catches compared to the setups without wool or with wool but not vibrating. Sheep wool, when vibrated, may release intensively volatile compounds, which could serve as olfactory cues, and play significant role in making the bait attractive to mosquitoes. Sheep wool is a readily available, affordable, and environment-friendly material. It should have the potential to be used as a mosquito management and surveillance component in dynamic bait setups.
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17
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Huff RM, Pitts RJ. Functional conservation of Anopheline linalool receptors through 100 million years of evolution. Chem Senses 2022; 47:bjac032. [PMID: 36458901 PMCID: PMC9717389 DOI: 10.1093/chemse/bjac032] [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: 12/05/2022] Open
Abstract
Insects rely on olfactory receptors to detect and respond to diverse environmental chemical cues. Detection of semiochemicals by these receptors modulates insect behavior and has a direct impact on species fitness. Volatile organic compounds (VOCs) are released by animals and plants and can provide contextual cues that a blood meal host or nectar source is present. One such VOC is linalool, an enantiomeric monoterpene, that is emitted from plants and bacteria species. This compound exists in nature as one of two possible stereoisomers, (R)-(-)-linalool or (S)-(+)-linalool. In this study, we use a heterologous expression system to demonstrate differential responsiveness of a pair of Anopheline odorant receptors (Ors) to enantiomers of linalool. The mosquitoes Anopheles gambiae and Anopheles stephensi encode single copies of Or29 and Or53, which are expressed in the labella of An. gambiae. (S)-(+)-linalool activates Or29 orthologs with a higher potency than (R)-(-)-linalool, while the converse is observed for Or53 orthologs. The conservation of these receptors across a broad range of Anopheline species suggests they may function in the discrimination of linalool stereoisomers, thereby influencing the chemical ecology of mosquitoes. One potential application of this knowledge would be in the design of novel attractants or repellents to be used in integrated pest management practices.
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Affiliation(s)
- Robert M Huff
- Department of Biology, Baylor University, Waco, TX 76706, USA
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18
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Fikrig K, Harrington LC. Understanding and interpreting mosquito blood feeding studies: the case of Aedes albopictus. Trends Parasitol 2021; 37:959-975. [PMID: 34497032 DOI: 10.1016/j.pt.2021.07.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/31/2022]
Abstract
Blood feeding is a fundamental mosquito behavior with consequences for pathogen transmission and control. Feeding behavior can be studied through two lenses - patterns and preference. Feeding patterns are assessed via blood meal analyses, reflecting mosquito-host associations influenced by environmental and biological parameters. Bias can profoundly impact results, and we provide recommendations for mitigating these effects. We also outline design choices for host preference research, which can take many forms, and highlight their respective (dis)advantages for preference measurement. Finally, Aedes albopictus serves as a case study for how to apply these lessons to interpret data and understand feeding biology. We illustrate how assumptions and incomplete evidence can lead to inconsistent interpretations by reviewing Ae. albopictus feeding studies alongside prevalent narratives about perceived behavior.
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Affiliation(s)
- Kara Fikrig
- Department of Entomology, Cornell University, Ithaca, NY, USA.
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19
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Caballero-Vidal G, Bouysset C, Gévar J, Mbouzid H, Nara C, Delaroche J, Golebiowski J, Montagné N, Fiorucci S, Jacquin-Joly E. Reverse chemical ecology in a moth: machine learning on odorant receptors identifies new behaviorally active agonists. Cell Mol Life Sci 2021; 78:6593-6603. [PMID: 34448011 PMCID: PMC8558168 DOI: 10.1007/s00018-021-03919-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 07/23/2021] [Accepted: 08/11/2021] [Indexed: 12/03/2022]
Abstract
The concept of reverse chemical ecology (exploitation of molecular knowledge for chemical ecology) has recently emerged in conservation biology and human health. Here, we extend this concept to crop protection. Targeting odorant receptors from a crop pest insect, the noctuid moth Spodoptera littoralis, we demonstrate that reverse chemical ecology has the potential to accelerate the discovery of novel crop pest insect attractants and repellents. Using machine learning, we first predicted novel natural ligands for two odorant receptors, SlitOR24 and 25. Then, electrophysiological validation proved in silico predictions to be highly sensitive, as 93% and 67% of predicted agonists triggered a response in Drosophila olfactory neurons expressing SlitOR24 and SlitOR25, respectively, despite a lack of specificity. Last, when tested in Y-maze behavioral assays, the most active novel ligands of the receptors were attractive to caterpillars. This work provides a template for rational design of new eco-friendly semiochemicals to manage crop pest populations.
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Affiliation(s)
- Gabriela Caballero-Vidal
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université de Paris, Institute of Ecology and Environmental Sciences of Paris, 78000, Versailles, France.,Disease Vector Group, Chemical Ecology Unit, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.,Max Planck Centre Next Generation Chemical Ecology, Uppsala, Sweden
| | - Cédric Bouysset
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice UMR7272, 28 avenue Valrose, 06108, Nice, France
| | - Jérémy Gévar
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université de Paris, Institute of Ecology and Environmental Sciences of Paris, 78000, Versailles, France
| | - Hayat Mbouzid
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université de Paris, Institute of Ecology and Environmental Sciences of Paris, 78000, Versailles, France
| | - Céline Nara
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université de Paris, Institute of Ecology and Environmental Sciences of Paris, 78000, Versailles, France
| | - Julie Delaroche
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université de Paris, Institute of Ecology and Environmental Sciences of Paris, 78000, Versailles, France
| | - Jérôme Golebiowski
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice UMR7272, 28 avenue Valrose, 06108, Nice, France.,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, 711-873, South Korea
| | - Nicolas Montagné
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université de Paris, Institute of Ecology and Environmental Sciences of Paris, 78000, Versailles, France.
| | - Sébastien Fiorucci
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice UMR7272, 28 avenue Valrose, 06108, Nice, France.
| | - Emmanuelle Jacquin-Joly
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université de Paris, Institute of Ecology and Environmental Sciences of Paris, 78000, Versailles, France.
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20
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Chen Q, Liu X, Cao S, Ma B, Guo M, Shen J, Wang G. Fine Structure and Olfactory Reception of the Labial Palps of Spodoptera frugiperda. Front Physiol 2021; 12:680697. [PMID: 34413785 PMCID: PMC8369160 DOI: 10.3389/fphys.2021.680697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/24/2021] [Indexed: 11/27/2022] Open
Abstract
The olfactory system of insects is essential in many crucial behaviors, such as host seeking, mate recognition, and locating oviposition sites. Lepidopteran moths possess two main olfactory organs, including antennae and labial palps. Compared to antennae, the labial palps are relatively specific and worthy of further investigation due to the labial-palp pit organ (LPO), which contains a large number of sensilla located on the tip segment. The fall armyworm, Spodoptera frugiperda, is a worldwide lepidopteran pest, which can damage more than 350 plants and cause significant economic losses. In this study, we surveyed the structure of the labial palps and LPO of S. frugiperda using a super-high magnification lens zoom 3D microscope. Then, the distribution and fine structure of sensilla located in the LPO of S. frugiperda were investigated using scanning electron microscopy. Subsequently, the electrophysiological responses of labial palps to CO2 and 29 plant volatiles were recorded by using electrolabialpalpography. Our results showed the fine structure of labial palps, the LPO, and the sensilla located in the LPO of S. frugiperda. Moreover, we demonstrated that the labial palps are olfactory organs that respond to both CO2 and other volatile compounds. Our work established a foundation for further study of the roles of labial palps in insect olfactory related behaviors. Further investigations on the function of labial palps and their biological roles together with CO2 and volatile compound responses in S. frugiperda are necessary, as they may provide better insect behavioral regulators for controlling this pest.
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Affiliation(s)
- Qiuyan Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Department of Entomology and MOA Key Laboratory for Monitory and Green Control of Crop Pest, China Agricultural University, Beijing, China
| | - Xiaolan Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Song Cao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Baiwei Ma
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mengbo Guo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Jie Shen
- Department of Entomology and MOA Key Laboratory for Monitory and Green Control of Crop Pest, China Agricultural University, Beijing, China
| | - Guirong Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
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21
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Athrey G, Popkin-Hall ZR, Takken W, Slotman MA. The Expression of Chemosensory Genes in Male Maxillary Palps of Anopheles coluzzii (Diptera: Culicidae) and An. quadriannulatus. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:1012-1020. [PMID: 33576414 PMCID: PMC8122237 DOI: 10.1093/jme/tjaa290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Indexed: 06/12/2023]
Abstract
Because of its importance as a malaria vector, Anopheles coluzzii's Coetzee & Wilkerson olfactory system has been studied extensively. Among this work is a series of studies comparing the expression of chemosensory genes in olfactory organs in females and/or males of these species. These have identified species- and female-biased chemosensory gene expression patterns. However, many questions remain about the role of chemosensation in male anopheline biology. To pave the way for future work we used RNAseq to compare chemosensory gene expression in the male maxillary palps of An. coluzzii and its sibling species An. quadriannulatus Theobald. As expected, the chemosensory gene repertoire is small in the male maxillary palps. Both species express the tuning receptors Or8 and Or28 at relatively high levels. The CO2 receptor genes Gr22-Gr24 are present in both species as well, although at much lower level than in females. Additionally, several chemoreceptors are species-specific. Gr37 and Gr52 are exclusive to An. coluzzii, whereas Or9 and Gr60 were detected only in An. quadriannulatus. Furthermore, several chemosensory genes show differential expression between the two species. Finally, several Irs, Grs, and Obps that show strong differential expression in the female palps, are absent or lowly expressed in the male palps. While many questions remain about the role of chemosensation in anopheline male biology, these results suggest that the male maxillary palps could have both a sex- and species-specific role in the perception of chemical stimuli. This work may guide future studies on the role of the male maxillary palp in these species.
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Affiliation(s)
- Giridhar Athrey
- Department of Poultry Science, Texas A&M University, College Station, TX
| | | | - Willem Takken
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Michel A Slotman
- Department of Entomology, Texas A&M University, College Station, TX
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22
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Contributions of the Conserved Insect Carbon Dioxide Receptor Subunits to Odor Detection. Cell Rep 2021; 31:107510. [PMID: 32294446 DOI: 10.1016/j.celrep.2020.03.074] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 08/19/2019] [Accepted: 03/23/2020] [Indexed: 01/18/2023] Open
Abstract
The CO2 receptor in mosquitoes is broadly tuned to detect many diverse odorants. The receptor consists of three subunits (Gr1, Gr2, and Gr3) in mosquitoes but only two subunits in Drosophila: Gr21a (Gr1 ortholog) and Gr63a (Gr3 ortholog). We demonstrate that Gr21a is required for CO2 responses in Drosophila, as has been shown for Gr63a. Next, we generate a Drosophila double mutant for Gr21a and Gr63a, and in this background, we functionally express combinations of Aedes Gr1, Gr2, and Gr3 genes in the CO2 empty neuron. Only two subunits, Gr2 and Gr3, suffice for response to CO2. Addition of Gr1 increases sensitivity to CO2, whereas it decreases the response to pyridine. The inhibitory effect of the antagonist isobutyric acid is observed upon addition of Gr1. Gr1 therefore increases the diversity of ligands of the receptor and modulates the response of the receptor complex.
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23
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Konopka JK, Task D, Afify A, Raji J, Deibel K, Maguire S, Lawrence R, Potter CJ. Olfaction in Anopheles mosquitoes. Chem Senses 2021; 46:6246230. [PMID: 33885760 DOI: 10.1093/chemse/bjab021] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
As vectors of disease, mosquitoes are a global threat to human health. The Anopheles mosquito is the deadliest mosquito species as the insect vector of the malaria-causing parasite, which kills hundreds of thousands every year. These mosquitoes are reliant on their sense of smell (olfaction) to guide most of their behaviors, and a better understanding of Anopheles olfaction identifies opportunities for reducing the spread of malaria. This review takes a detailed look at Anopheles olfaction. We explore a range of topics from chemosensory receptors, olfactory neurons, and sensory appendages to behaviors guided by olfaction (including host-seeking, foraging, oviposition, and mating), to vector management strategies that target mosquito olfaction. We identify many research areas that remain to be addressed.
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Affiliation(s)
- Joanna K Konopka
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
| | - Darya Task
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
| | - Ali Afify
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
| | - Joshua Raji
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
| | - Katelynn Deibel
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
| | - Sarah Maguire
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
| | - Randy Lawrence
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
| | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 North Wolfe Street, 434 Rangos Building, Baltimore, 21205 MD, USA
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Campetella F, Ignell R, Beutel R, Hansson BS, Sachse S. Comparative dissection of the peripheral olfactory system of the Chagas disease vectors Rhodnius prolixus and Rhodnius brethesi. PLoS Negl Trop Dis 2021; 15:e0009098. [PMID: 33857145 PMCID: PMC8078792 DOI: 10.1371/journal.pntd.0009098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/27/2021] [Accepted: 03/24/2021] [Indexed: 11/19/2022] Open
Abstract
American trypanosomiasis, or Chagas disease, is transmitted by both domestic and sylvatic species of Triatominae which use sensory cues to locate their vertebrate hosts. Among them, odorants have been shown to play a key role. Previous work revealed morphological differences in the sensory apparatus of different species of Triatomines, but to date a comparative functional study of the olfactory system is lacking. After examining the antennal sensilla with scanning electronic microscopy (SEM), we compared olfactory responses of Rhodnius prolixus and the sylvatic Rhodnius brethesi using an electrophysiological approach. In electroantennogram (EAG) recordings, we first showed that the antenna of R. prolixus is highly responsive to carboxylic acids, compounds found in their habitat and the headspace of their vertebrate hosts. We then compared responses from olfactory sensory neurons (OSNs) housed in the grooved peg sensilla of both species, as these are tuned to these compounds using single-sensillum recordings (SSRs). In R. prolixus, the SSR responses revealed a narrower tuning breath than its sylvatic sibling, with the latter showing responses to a broader range of chemical classes. Additionally, we observed significant differences between these two species in their response to particular volatiles, such as amyl acetate and butyryl chloride. In summary, the closely related, but ecologically differentiated R. prolixus and R. brethesi display distinct differences in their olfactory functions. Considering the ongoing rapid destruction of the natural habitat of sylvatic species and the likely shift towards environments shaped by humans, we expect that our results will contribute to the design of efficient vector control strategies in the future.
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Affiliation(s)
- Florencia Campetella
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Rolf Beutel
- Institute for Zoology and Evolutionary Biology, Friedrich Schiller University, Jena, Germany
| | - Bill S. Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Silke Sachse
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
- * E-mail:
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25
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Chen ST, Kowalewski J, Ray A. Prolonged activation of carbon dioxide-sensitive neurons in mosquitoes. Interface Focus 2021; 11:20200043. [PMID: 33633836 DOI: 10.1098/rsfs.2020.0043] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 11/12/2022] Open
Abstract
Many insects can detect carbon dioxide (CO2) plumes using a conserved receptor made up of members of the gustatory receptor (Gr) family Gr1, Gr2 and Gr3. Mosquitoes are attracted to host animals for blood meals using plumes of CO2 in the exhaled breath using the receptor expressed in the A neuron of the capitate peg sensilla type on the maxillary palps. The receptor is known to also detect several other classes of odorants, including ones emitted from human skin. Here, we discover that a common skin odorant, butyric acid, can cause a phasic activation followed by an unusually prolonged tonic activity after the stimulus is over in the CO2 neurons of mosquitoes. The effect is conserved in both Aedes aegypti and Anopheles gambiae mosquitoes. This raises a question about its role in a mosquito's preference for the skin odour of different individuals. Butyric acid belongs to a small number of odorants known to cause the prolonged activation of the CO2 receptor. A chemical informatic analysis identifies a specific set of physico-chemical features that can be used in a machine learning predictive model for the prolonged activators. Interestingly, this set is different from physico-chemical features selected for activators or inhibitors, indicating that each has a distinct structural basis. The structural understanding opens up an opportunity to find novel ligands to manipulate the CO2 receptor and mosquito behaviour.
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Affiliation(s)
- Stephanie Turner Chen
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA 92521, USA
| | - Joel Kowalewski
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA
| | - Anandasankar Ray
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA 92521, USA.,Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA
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26
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Dormont L, Mulatier M, Carrasco D, Cohuet A. Mosquito Attractants. J Chem Ecol 2021; 47:351-393. [PMID: 33725235 DOI: 10.1007/s10886-021-01261-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/18/2021] [Accepted: 03/02/2021] [Indexed: 01/01/2023]
Abstract
Vector control and personal protection against anthropophilic mosquitoes mainly rely on the use of insecticides and repellents. The search for mosquito-attractive semiochemicals has been the subject of intense studies for decades, and new compounds or odor blends are regularly proposed as lures for odor-baited traps. We present a comprehensive and up-to-date review of all the studies that have evaluated the attractiveness of volatiles to mosquitoes, including individual chemical compounds, synthetic blends of compounds, or natural host or plant odors. A total of 388 studies were analysed, and our survey highlights the existence of 105 attractants (77 volatile compounds, 17 organism odors, and 11 synthetic blends) that have been proved effective in attracting one or several mosquito species. The exhaustive list of these attractants is presented in various tables, while the most common mosquito attractants - for which effective attractiveness has been demonstrated in numerous studies - are discussed throughout the text. The increasing knowledge on compounds attractive to mosquitoes may now serve as the basis for complementary vector control strategies, such as those involving lure-and-kill traps, or the development of mass trapping. This review also points out the necessity of further improving the search for new volatile attractants, such as new compound blends in specific ratios, considering that mosquito attraction to odors may vary over the life of the mosquito or among species. Finally, the use of mosquito attractants will undoubtedly have an increasingly important role to play in future integrated vector management programs.
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Affiliation(s)
- Laurent Dormont
- CEFE, Univ Paul Valéry Montpellier 3, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France.
| | - Margaux Mulatier
- Institut Pasteur de Guadeloupe, Laboratoire d'étude sur le contrôle des vecteurs (LeCOV), Lieu-Dit Morne Jolivièrex, 97139, Les Abymes, Guadeloupe, France
| | - David Carrasco
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France
| | - Anna Cohuet
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France
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27
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Chang CG, Hsu CH, Soong K. Navigation in darkness: How the marine midge (Pontomyia oceana) locates hard substrates above the water level to lay eggs. PLoS One 2021; 16:e0246060. [PMID: 33493219 PMCID: PMC7834138 DOI: 10.1371/journal.pone.0246060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/12/2021] [Indexed: 11/18/2022] Open
Abstract
Finding suitable habitats for specific functions such as breeding provides examples of key biotic adaptation. The adult marine midge Pontomyia oceana requires an extremely specific habitat, i.e., hard substrates above water in shallow water, to deposit fertilized eggs. We investigated how these sea surface-skimming insects accomplished this with a stringent time constraint of 1-2 h of the adult life span in the evenings. We observed that in artificial containers, midges aggregated at bright spots only if the light was not in the direction of the sea. This behavior could potentially attract midges toward the shore and away from the open water. Experiments were performed in the intertidal zone in southern Taiwan to test three hypotheses explaining such behavior: gradients of temperature and CO2, and soundscape. No differences were observed in moving directions or aggregation of midges under artificial temperature and CO2 gradients. However, midges preferred sounds at 75 Hz compared with other frequencies (all ≤300 Hz) as observed in a field experiment involving floating traps with loudspeakers. Moreover, when background noise was experimentally masked using white noise of all frequencies, midges were significantly more likely to aggregate at bright spots in the direction of the sea than in the absence of white noise. These results establish that sound is used by midges to navigate in dark seas and move toward the shore where exposed hard substrates are in abundance. Marine mammals present well-known cases of sound pollution at sea; here the finding in the insignificant marine midge is just the harbinger of the potential effects noise at shore may have to affect critical reproductive stages of marine organisms.
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Affiliation(s)
- Chun-Gin Chang
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Chia-Hsuan Hsu
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Keryea Soong
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, Taiwan
- * E-mail:
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28
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Wheelwright M, Whittle CR, Riabinina O. Olfactory systems across mosquito species. Cell Tissue Res 2021; 383:75-90. [PMID: 33475852 PMCID: PMC7873006 DOI: 10.1007/s00441-020-03407-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/15/2020] [Indexed: 01/06/2023]
Abstract
There are 3559 species of mosquitoes in the world (Harbach 2018) but, so far, only a handful of them have been a focus of olfactory neuroscience and neurobiology research. Here we discuss mosquito olfactory anatomy and function and connect these to mosquito ecology. We highlight the least well-known and thus most interesting aspects of mosquito olfactory systems and discuss promising future directions. We hope this review will encourage the insect neuroscience community to work more broadly across mosquito species instead of focusing narrowly on the main disease vectors.
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Affiliation(s)
- Matthew Wheelwright
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK
| | - Catherine R Whittle
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK
| | - Olena Riabinina
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK.
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29
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Liu F, Ye Z, Baker A, Sun H, Zwiebel LJ. Gene editing reveals obligate and modulatory components of the CO 2 receptor complex in the malaria vector mosquito, Anopheles coluzzii. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 127:103470. [PMID: 32966873 PMCID: PMC7704673 DOI: 10.1016/j.ibmb.2020.103470] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/12/2020] [Accepted: 09/12/2020] [Indexed: 05/28/2023]
Abstract
The sensitivity to volatile carbon dioxide (CO2) produced by humans and other animals is a critical component in the host preference behaviors of the malaria vector mosquito Anopheles coluzzii. The molecular receptors responsible for the ability to sense CO2 are encoded by three putative gustatory receptor (Gr) genes (Gr22,23,24) which are expressed in a distinctive array of sensory neurons housed in maxillary palp capitate peg sensilla of An. coluzzii. Despite the identification of these components and subsequent studies, there is a paucity of understanding regarding the respective roles of these three GRs in the mosquito's CO2 transduction process. To address this, we have used CRISPR/Cas9-based gene editing technique combined with in vivo electrophysiological recordings to directly examine the role of Gr22,23,24 in detecting CO2 in An. coluzzii. These studies reveal that both Gr23 and Gr24 are absolutely required to maintain in vivo CO2 sensitivity while, in contrast, Gr22 knock out mutants are still able to respond to CO2 stimuli albeit with significantly weaker sensitivity. Our data supports a model in which Gr22 plays a modulatory role to enhance the functionality of Gr23/24 complexes that are responsible for CO2 sensitivity of mosquitoes.
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Affiliation(s)
- Feng Liu
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN, 37235, USA
| | - Zi Ye
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN, 37235, USA
| | - Adam Baker
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN, 37235, USA
| | - Huahua Sun
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN, 37235, USA
| | - Laurence J Zwiebel
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN, 37235, USA.
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30
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Wu Z, Cui Y, Ma J, Qu M, Lin J. Analyses of chemosensory genes provide insight into the evolution of behavioral differences to phytochemicals in Bactrocera species. Mol Phylogenet Evol 2020; 151:106858. [DOI: 10.1016/j.ympev.2020.106858] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 05/15/2020] [Accepted: 05/21/2020] [Indexed: 02/07/2023]
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31
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Passive Outdoor Host Seeking Device (POHD): Designing and Evaluation against Outdoor Biting Malaria Vectors. ScientificWorldJournal 2020; 2020:4801068. [PMID: 32694955 PMCID: PMC7350071 DOI: 10.1155/2020/4801068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 05/26/2020] [Accepted: 06/01/2020] [Indexed: 11/17/2022] Open
Abstract
Odor-baited devices are increasingly needed to compliment long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) for control of residual malaria transmission. However, the odor-baited devices developed so far are bulky, dependent on the source of electricity and carbon dioxide (CO2), and they are logistically unsuitable for scaling up in surveillance and control of malaria vectors. We designed a passive and portable outdoor host seeking device (POHD) and preliminarily evaluated suitable components against Anopheles arabiensis that maintains residual malaria transmission. Experiments were conducted using semifield reared An. arabiensis within the semifield system at Ifakara Health Institute (IHI) in southeastern Tanzania. These mosquitoes were exposed to Suna traps® baited with BG lures or source of light and augmented with carbon dioxide (CO2) in view of identifying best attractants necessary to improve attractiveness of designed POHD. Two Suna traps® were hanged at the corner but outside the experimental hut in a diagonal line and rotated between four corners to control for the effect of position and wind direction on mosquito catches. Furthermore, mosquitoes were also exposed to either a bendiocarb-treated or bendiocarb-untreated POHD baited with Mbita blend, Ifakara blend, and worn socks and augmented with warmth (i.e., 1.5 liter bottle of warm water) inside an experimental hut or a screened rectangular box. This study demonstrated that mosquitoes were more strongly attracted to Suna trap® baited with BG lures and CO2 relative to those traps baited with a source of light and CO2. The POHD baited with synthetic blends attracted and killed greater proportion of An. arabiensis compared with POHD baited with worn socks. Efficacy of the POHD was unaffected by source of warmth, and it was reduced by about 50% when the device was tested inside a screened rectangular box relative to closed experimental hut. Overall, this study demonstrates that the POHD baited with synthetic blends (Mbita and Ifakara blends) and bendiocarb can effectively attract and kill outdoor biting malaria vector species. Such POHD baited with synthetic blends may require the source of CO2 to enhance attractiveness to mosquitoes. Further trials are, therefore, ongoing to evaluate attractiveness of improved design of POHD baited with slow-release formulation of synthetic blends and sustainable source of CO2 to malaria vectors under semifield and natural environments.
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32
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Wooding M, Rohwer ER, Naudé Y. Chemical profiling of the human skin surface for malaria vector control via a non-invasive sorptive sampler with GC×GC-TOFMS. Anal Bioanal Chem 2020; 412:5759-5777. [PMID: 32681223 DOI: 10.1007/s00216-020-02799-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/26/2020] [Accepted: 07/01/2020] [Indexed: 12/28/2022]
Abstract
Volatile organic compounds (VOCs) and semi-VOCs detected on the human skin surface are of great interest to researchers in the fields of metabolomics, diagnostics, and skin microbiota and in the study of anthropophilic vector mosquitoes. Mosquitoes use chemical cues to find their host, and humans can be ranked for attractiveness to mosquitoes based on their skin chemical profile. Additionally, mosquitoes show a preference to bite certain regions on the human host. In this study, the chemical differences in the skin surface profiles of 20 human volunteers were compared based on inter-human attractiveness to mosquitoes, as well as inter- and intra-human mosquito biting site preference. A passive, non-invasive approach was followed to sample the wrist and ankle skin surface region. An in-house developed polydimethylsiloxane (PDMS) passive sampler was used to concentrate skin VOCs and semi-VOCs prior to thermal desorption directly in the GC inlet with comprehensive gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS). Compounds from a broad range of chemical classes were detected and identified as contributing to the differences in the surface skin chemical profiles. 5-Ethyl-1,2,3,4-tetrahydronaphthalene, 1,1'-oxybisoctane, 2-(dodecyloxy)ethanol, α,α-dimethylbenzene methanol, methyl salicylate, 2,6,10,14-tetramethylhexadecane, 1,2-benzenedicarboxylic acid, bis(2-methylpropyl) ester, 4-methylbenzaldehyde, 2,6-diisopropylnaphthalene, n-hexadecanoic acid, and γ-oxobenzenebutanoic acid ethyl ester were closely associated with individuals who perceived themselves as attractive for mosquitoes. Additionally, biological lead compounds as potential attractants or repellants in vector control strategies were tentatively identified. Results augment current knowledge on human skin chemical profiles and show the potential of using a non-invasive sampling approach to investigate anthropophilic mosquito-host interactions. Graphical abstract.
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Affiliation(s)
- Madelien Wooding
- Department of Chemistry, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - Egmont R Rohwer
- Department of Chemistry, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - Yvette Naudé
- Department of Chemistry, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
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33
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Xu Q, Wu Z, Zeng X, An X. Identification and Expression Profiling of Chemosensory Genes in Hermetia illucens via a Transcriptomic Analysis. Front Physiol 2020; 11:720. [PMID: 32655421 PMCID: PMC7325966 DOI: 10.3389/fphys.2020.00720] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 05/29/2020] [Indexed: 02/03/2023] Open
Abstract
The black soldier fly, Hermetia illucens, is a cosmopolitan insect of the family Stratiomyidae (Diptera). Chemosensory genes encode proteins involved directly in the detection of odorants. In this study, we sequenced the antennal transcriptome of H. illucens adults to identify chemosensory genes. Putative unigenes encoding 27 odorant binding proteins (OBPs), five chemosensory proteins (CSPs), 70 odorant receptors (ORs), 25 ionotropic receptors (IRs), 10 gustatory receptors (GRs) and two sensory neuron membrane proteins (SNMPs) were identified. Tissue-specific expression profiles of the identified OBPs, CSPs and SNMPs were investigated using RT-PCR. Eight OBPs (HillOBP1-2, 9, 11-14, and 17), one CSP (HillCSP5) and one SNMP (HillSNMP1) were predominantly expressed in antennae. Further real-time quantitative PCR analyses revealed that the antennae-enriched unigenes also exhibited significant differences in expression between males and females. Among the sex-biased unigenes, six ORs showed female-biased expression, suggesting that these genes might participate in female-specific behaviors such as oviposition site searching. Sixteen ORs and two OBPs showed male-biased expression, indicating that they may play key roles in the detection of female sex pheromones. Our study is the first attempt to delineate the molecular basis of chemoreception in H. illucens. Our data provide useful information for comparative studies on the differentiation and evolution of Dipteran chemosensory gene families.
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Affiliation(s)
- Qiyun Xu
- Guangdong Engineering Research Center for Insect Behavior Regulation, College of Agriculture, South China Agricultural University, Guangzhou, China.,Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, China
| | - Zhongzhen Wu
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Xinnian Zeng
- Guangdong Engineering Research Center for Insect Behavior Regulation, College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Xincheng An
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, China
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34
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Kessy ST, Nyundo BA, Mnyone LL, Lyimo IN. The Use of Granular Cyclopentanone as Alternative to Artificial Source of Carbon Dioxide in Improved Passive Outdoor Host Seeking Device (POHD). ScientificWorldJournal 2020; 2020:7620389. [PMID: 32581659 PMCID: PMC7306862 DOI: 10.1155/2020/7620389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 04/07/2020] [Accepted: 05/16/2020] [Indexed: 11/18/2022] Open
Abstract
Reliable sources of CO2 that are relatively cheap, obtainable, and easy to sustain are immediately required for scaling up of odor-baited mosquito surveillance and control devices. Several odor-baited devices are in the pipeline; however, their scale-up against residual malaria transmission, particularly in resource poor areas, is limited by the unavailability of reliable sources of CO2 and reliance on electrical power sources among other factors. We evaluated the use of granular cyclopentanone as an alternative to artificial or yeast fermentation-produced CO2 in passive outdoor host seeking device (POHD). Experiments were conducted against semifield reared An. arabiensis within the semifield system (SFS) at Ifakara Health Institute. Mosquitoes were tested against odor-baited POHDs augmented with yeast fermentation-produced CO2, granular cyclopentanone, attractive blends (Mbita or Ifakara), or their combinations. An insecticide, bendiocarb, was a killing agent used as a proxy for marking the mosquitoes visit the POHDs. Relative attractiveness of different treatment combinations was compared based on the proportion of dead mosquitoes that visited the POHD. The POHD augmented with granules of cyclopentanone alone was attractive to An. arabiensis as much as, or more than, POHDs augmented with yeast fermentation-produced CO2. The POHD baited with CO2 attracted more mosquitoes than those POHDs baited with synthetic blends alone; when these blends are combined with CO2, they attracted more mosquitoes than individual blends. More importantly, such POHDs baited with cyclopentanone attracted far greater proportion of mosquitoes than the POHD baited with either Mbita or Ifakara blend alone. The granular cyclopentanone strongly enhanced/potentiated the attractiveness of POHD baited with Mbita blends against mosquitoes compared to that of POHD baited with Ifakara blend. Moreover, the granular cyclopentanone retained its residual activity against An. arabiensis for up to 2 months after application particularly when used in combination with Mbita blend. In conclusion, this study demonstrates that cyclopentanone granules have the potential to substitute sources of CO2 in outdoor-based surveillance and control devices, thus warranting evaluation of such alternative under realistic field conditions.
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Affiliation(s)
- Stella T. Kessy
- Department of Environmental Health and Ecological Sciences, Ifakara Health Institute, P.O. Box 53, Off Mlabani Passage, Ifakara, Morogoro, Tanzania
| | - Bruno A. Nyundo
- Zoology and Wildlife Conservation Department, College of Natural and Applied Science, University of Dar Es Salaam, P.O. Box 35091, Dar Es Salaam, Tanzania
| | - Ladslaus L. Mnyone
- Department of Environmental Health and Ecological Sciences, Ifakara Health Institute, P.O. Box 53, Off Mlabani Passage, Ifakara, Morogoro, Tanzania
- Pest Management Centre, Sokoine University of Agriculture, P.O. Box 3110, Morogoro, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Issa N. Lyimo
- Department of Environmental Health and Ecological Sciences, Ifakara Health Institute, P.O. Box 53, Off Mlabani Passage, Ifakara, Morogoro, Tanzania
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35
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Caballero-Vidal G, Bouysset C, Grunig H, Fiorucci S, Montagné N, Golebiowski J, Jacquin-Joly E. Machine learning decodes chemical features to identify novel agonists of a moth odorant receptor. Sci Rep 2020; 10:1655. [PMID: 32015393 PMCID: PMC6997167 DOI: 10.1038/s41598-020-58564-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 01/09/2020] [Indexed: 11/24/2022] Open
Abstract
Odorant receptors expressed at the peripheral olfactory organs are key proteins for animal volatile sensing. Although they determine the odor space of a given species, their functional characterization is a long process and remains limited. To date, machine learning virtual screening has been used to predict new ligands for such receptors in both mammals and insects, using chemical features of known ligands. In insects, such approach is yet limited to Diptera, whereas insect odorant receptors are known to be highly divergent between orders. Here, we extend this strategy to a Lepidoptera receptor, SlitOR25, involved in the recognition of attractive odorants in the crop pest Spodoptera littoralis larvae. Virtual screening of 3 million molecules predicted 32 purchasable ones whose function has been systematically tested on SlitOR25, revealing 11 novel agonists with a success rate of 28%. Our results show that Support Vector Machine optimizes the discovery of novel agonists and expands the chemical space of a Lepidoptera OR. More, it opens up structure-function relationship analyses through a comparison of the agonist chemical structures. This proof-of-concept in a crop pest could ultimately enable the identification of OR agonists or antagonists, capable of modifying olfactory behaviors in a context of biocontrol.
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Affiliation(s)
- Gabriela Caballero-Vidal
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université Paris Diderot, Institute of Ecology and Environmental Sciences of Paris, Paris, Versailles, France
| | - Cédric Bouysset
- Institute of Chemistry of Nice, UMR CNRS 7272, Université Côte d'Azur, Nice, France
| | - Hubert Grunig
- Institute of Chemistry of Nice, UMR CNRS 7272, Université Côte d'Azur, Nice, France
| | - Sébastien Fiorucci
- Institute of Chemistry of Nice, UMR CNRS 7272, Université Côte d'Azur, Nice, France
| | - Nicolas Montagné
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université Paris Diderot, Institute of Ecology and Environmental Sciences of Paris, Paris, Versailles, France.
| | - Jérôme Golebiowski
- Institute of Chemistry of Nice, UMR CNRS 7272, Université Côte d'Azur, Nice, France. .,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, 711-873, South Korea.
| | - Emmanuelle Jacquin-Joly
- INRAE, Sorbonne Université, CNRS, IRD, UPEC, Université Paris Diderot, Institute of Ecology and Environmental Sciences of Paris, Paris, Versailles, France.
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36
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Chin SG, Maguire SE, Huoviala P, Jefferis GSXE, Potter CJ. Olfactory Neurons and Brain Centers Directing Oviposition Decisions in Drosophila. Cell Rep 2020; 24:1667-1678. [PMID: 30089274 PMCID: PMC6290906 DOI: 10.1016/j.celrep.2018.07.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 04/30/2018] [Accepted: 07/04/2018] [Indexed: 01/19/2023] Open
Abstract
The sense of smell influences many behaviors, yet how odors are represented in the brain remains unclear. A major challenge to studying olfaction is the lack of methods allowing activation of specific types of olfactory neurons in an ethologically relevant setting. To address this, we developed a genetic method in Drosophila called olfactogenetics in which a narrowly tuned odorant receptor, Or56a, is ectopically expressed in different olfactory neuron types. Stimulation with geosmin (the only known Or56a ligand) in an Or56a mutant background leads to specific activation of only target olfactory neuron types. We used this approach to identify olfactory sensory neurons (OSNs) that directly guide oviposition decisions. We identify 5 OSN-types (Or71a, Or47b, Or49a, Or67b, and Or7a) that, when activated alone, suppress oviposition. Projection neurons partnering with these OSNs share a region of innervation in the lateral horn, suggesting that oviposition site selection might be encoded in this brain region.
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Affiliation(s)
- Sonia G Chin
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Sarah E Maguire
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Paavo Huoviala
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 OQH, UK
| | - Gregory S X E Jefferis
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 OQH, UK
| | - Christopher J Potter
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205, USA.
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Emami SN, Hajkazemian M, Mozūraitis R. Can Plasmodium's tricks for enhancing its transmission be turned against the parasite? New hopes for vector control. Pathog Glob Health 2020; 113:325-335. [PMID: 31910740 PMCID: PMC7008238 DOI: 10.1080/20477724.2019.1703398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Approximately 120 years ago the link between mosquito and the malaria transmission was discovered. However, even today it remains an open question whether the parasite is able to direct the blood-seeking and feeding behavior of its mosquito vector to maximize the probability of transmission. If the parasite has this ability, could it occur only through the alteration of the vertebrate host's volatile organic compounds (VOCs) and/or the parasite alteration of the behavior of the infected vector in a manner that favors its transmission? Although some recent empirical evidence supports the hypothesis regarding the parasite ability in alteration of the vertebrate host's VOCs, the role of parasite alteration and behavioral differences between infected and uninfected female mosquitoes toward infected and uninfected hosts has not yet been considered in the implementation of control measures. This review will discuss the current evidence, which shows 1. Plasmodium can direct uninfected mosquito blood-seeking and feeding behavior via alteration of vertebrate-host odor profiles and production of phagostimulants and 2. Plasmodium also manipulates its vector during the sporogony cycle to increase transmission. Briefly, we also consider the next generation of methods for moving the empirical laboratory evidence to potential application in future integrated malaria control programs.
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Affiliation(s)
- S Noushin Emami
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Melika Hajkazemian
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Raimondas Mozūraitis
- Department of Zoology, Stockholm University, Stockholm, Sweden.,Laboratory of Chemical and Behavioral Ecology, Institute of Ecology, Nature Research Centre, Vilnius, Lithuania
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38
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Ghaninia M, Majeed S, Dekker T, Hill SR, Ignell R. Hold your breath - Differential behavioral and sensory acuity of mosquitoes to acetone and carbon dioxide. PLoS One 2019; 14:e0226815. [PMID: 31887129 PMCID: PMC6936819 DOI: 10.1371/journal.pone.0226815] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 12/04/2019] [Indexed: 01/16/2023] Open
Abstract
Host seeking in the yellow fever mosquito, Aedes aegypti, and the African malaria mosquito, Anopheles coluzzii, relies on specific and generic host-derived odorants. Previous analyses indicate that the behavioral response of these species depends differentially on the presence of carbon dioxide (CO2) and other constituents in human breath for activation and attraction. In this study, we use a flight tube assay and electrophysiological analysis to assess the role of acetone, a major component of exhaled human breath, in modulating the behavioral and sensory neuronal response of these mosquito species, in the presence and absence of CO2. When presented alone at ecologically relevant concentrations, acetone increases attraction in Ae. aegypti, but not in An. coluzzii. Moreover, in combination with CO2, human breath-equivalents of acetone ranging between 0.1 and 10 ppm reproduces a behavioral response similar to that observed to human breath in host-seeking Ae. aegypti, but not in An. coluzzii. Acetone does, however, reduce attraction to CO2 in An. coluzzii, when presented at a higher concentration of 10 ppm. We identify the capitate peg A neuron of the maxillary palp of both species as a dual detector of CO2 and acetone. The sensory response to acetone, or binary blends of acetone and CO2, reflects the observed behavioral output in both Ae. aegypti and An. coluzzii. We conclude that host recognition is contextual and dependent on a combination of ecologically relevant odorants at naturally occurring concentrations that are encoded, in this case, by differences in the temporal structure of the neuronal response. This information should be considered when designing synthetic blends for that optimally attract mosquitoes for monitoring and control.
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Affiliation(s)
- Majid Ghaninia
- School of Life Sciences, Arizona State University, Tempe, AZ, United States of America
- Division of Entomology, Department of Plant Protection, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
| | - Shahid Majeed
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Teun Dekker
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Sharon R. Hill
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Rickard Ignell
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
- * E-mail:
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39
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Omondi WP, Owino EA, Odongo D, Mwangangi JM, Torto B, Tchouassi DP. Differential response to plant- and human-derived odorants in field surveillance of the dengue vector, Aedes aegypti. Acta Trop 2019; 200:105163. [PMID: 31494122 DOI: 10.1016/j.actatropica.2019.105163] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/04/2019] [Accepted: 09/04/2019] [Indexed: 01/20/2023]
Abstract
Linalool oxide (LO) and hexanoic acid (HA) represent plant- and human-derived odorants, respectively, previously found as attractants for the dengue vector Aedes aegypti. Here, we investigated if a blend of both compounds can improve captures of this mosquito species in field trials in two dengue endemic sites, Kilifi and Busia Counties in Kenya. Ae. aegypti captures were significantly higher in Kilifi than Busia (χ21,142 = 170.63, P < 0.0001) and varied by treatments (χ25,137 = 151.19, P = 0.002). We found that CO2-baited BG Sentinel traps combined with a blend of both odorants decreased Ae. aegypti captures about 2- to 4-fold compared to captures with the individual compounds (LO or HA) used as positive controls. This was the case for all blends of LO and HA, irrespective of the doses tested. Our findings indicate that combining plant- and human-derived odors may elicit a masking effect in trapping Ae. aegypti. These results partly corroborate previous findings for malaria mosquitoes which showed that combining lures from both host sources either decreases or increases trap catches depending on the dose. Further investigations in the usefulness of combining plant and animal odorants in mosquito trapping are therefore necessary.
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Affiliation(s)
- Wyckliff P Omondi
- School of Biological Sciences, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya; International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - Eunice A Owino
- School of Biological Sciences, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
| | - David Odongo
- School of Biological Sciences, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
| | - Joseph M Mwangangi
- Centre for Geographic Medicine Research Coast, Kenya Medical Research Institute (KEMRI), P.O. Box 42880-108, Kilifi, Kenya
| | - Baldwyn Torto
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - David P Tchouassi
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya.
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Saleh FM, Abdelhamid AO, Hassaneen HM. Synthesis and antimicrobial activity of new thiazole and thiadiazole derivatives via ethyl pyruvate. J Sulphur Chem 2019. [DOI: 10.1080/17415993.2019.1694678] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Fatma M. Saleh
- Faculty of Science, Department of Chemistry, Cairo University, Giza, Egypt
| | | | - Hamdi M. Hassaneen
- Faculty of Science, Department of Chemistry, Cairo University, Giza, Egypt
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Tchouassi DP, Jacob JW, Ogola EO, Sang R, Torto B. Aedes vector-host olfactory interactions in sylvatic and domestic dengue transmission environments. Proc Biol Sci 2019; 286:20192136. [PMID: 31690238 DOI: 10.1098/rspb.2019.2136] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Interactions between Aedes (Stegomyia) species and non-human primate (NHP) and human hosts govern the transmission of the pathogens, dengue, zika, yellow fever and chikungunya viruses. Little is known about Aedes mosquito olfactory interactions with these hosts in the domestic and sylvatic cycles where these viruses circulate. Here, we explore how the different host-derived skin odours influence Aedes mosquito responses in these two environments. In field assays, we show that the cyclic ketone cyclohexanone is a signature cue for Aedes mosquitoes to detect the NHP baboon, sykes and vervet, whereas for humans, it is the unsaturated aliphatic keto-analogue 6-methyl-5-hepten-2-one (sulcatone). We find that in the sylvatic environment, CO2-baited traps combined with either cyclohexanone or sulcatone increased trap catches of Aedes mosquitoes compared to traps either baited with CO2 alone or CO2 combined with NHP- or human-derived crude skin odours. In the domestic environment, each of these odourants and crude human skin odours increased Aedes aegypti catches in CO2-baited traps. These results expand our knowledge on the role of host odours in the ecologies of Aedes mosquitoes, and the likelihood of associated spread of pathogens between primates and humans. Both cyclohexanone and sulcatone have potential practical applications as lures for monitoring Aedes disease vectors.
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Affiliation(s)
- David P Tchouassi
- International Centre of Insect Physiology and Ecology, PO Box 30772-00100, Nairobi, Kenya
| | - Juliah W Jacob
- International Centre of Insect Physiology and Ecology, PO Box 30772-00100, Nairobi, Kenya
| | - Edwin O Ogola
- International Centre of Insect Physiology and Ecology, PO Box 30772-00100, Nairobi, Kenya
| | - Rosemary Sang
- International Centre of Insect Physiology and Ecology, PO Box 30772-00100, Nairobi, Kenya
| | - Baldwyn Torto
- International Centre of Insect Physiology and Ecology, PO Box 30772-00100, Nairobi, Kenya
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42
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Zhou LY, Li W, Liu HY, Xiang F, Kang YK, Yin X, Huang AP, Wang YJ. Systemic identification and analyses of genes potentially involved in chemosensory in the devastating tea pest Basilepta melanopus. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2019; 31:100586. [DOI: 10.1016/j.cbd.2019.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 04/03/2019] [Accepted: 04/06/2019] [Indexed: 11/27/2022]
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Xie L, Yang W, Liu H, Liu T, Xie Y, Lin F, Zhou G, Zhou X, Wu K, Gu J, Yan G, Chen XG. Enhancing attraction of the vector mosquito Aedes albopictus by using a novel synthetic odorant blend. Parasit Vectors 2019; 12:382. [PMID: 31362759 PMCID: PMC6668062 DOI: 10.1186/s13071-019-3646-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/25/2019] [Indexed: 12/02/2022] Open
Abstract
Background The Asian tiger mosquito, Aedes albopictus, an increasingly relevant arboviral vector, has spread worldwide. However, currently available tools are limited in terms of effective monitoring of vector populations and accurate determination of the extent of viral transmission, especially before and during outbreaks. Therefore, it is essential to develop novel monitoring and surveillance tools, particularly those that target adult mosquitoes and enhance the trapping efficiency for Ae. albopictus. Methods A variety of human body odorants associated with different types of mosquito olfactory receptors were selected, and their attractiveness to Ae. albopictus was tested by a four-arm olfactometer. The optimal compatibility and proportion of the odorants, Mix-5, was observed via orthogonal design analyses. The attractiveness of Mix-5 to Ae. albopictus in the laboratory was assessed using Mosq-ovitraps and Electric Mosquito Killers. In the field, the effectiveness of generic BG-Lure, Mix-5 and a control treatment was compared with a baited Biogents Sentinel trap (BGS-trap) using a Latin square design. Results In the olfactometer experiments, the attractiveness of the selected candidate compounds at varying dilutions was poor when the individual compounds were used alone. The optimal combination, Mix-5, was generated based on orthogonal design analyses. In the laboratory, the average numbers of female Ae. albopictus mosquitoes attracted by the synthetic odorant blend Mix-5 were 27.00 and 27.50, compared with 12.00 and 14.83 for the control, when using Mosq-ovitraps and Electric Mosquito Killers, respectively. In the field, the average number of Ae. albopictus female mosquitoes trapped by Mix-5 was 9.67 females/trap, whereas the average numbers for BG-Lure and the control were 7.78 and 4.47, respectively. The lure also played an important role in attracting Culex quinquefasciatus mosquitoes, and the average numbers of Cx. quinquefasciatus female mosquitoes attracted by Mix-5, BG-Lure and the control were 18.78, 25.11 and 12.22, respectively. Conclusions A human odor-based bait blend was developed and exhibited enhanced effectiveness at attracting Ae. albopictus This blend can be used to monitor and trap dengue vector mosquitoes in Chinese cities. Electronic supplementary material The online version of this article (10.1186/s13071-019-3646-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lihua Xie
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Wenqiang Yang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Hongmei Liu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Tong Liu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yugu Xie
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Feng Lin
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Guofa Zhou
- Program in Public Health, University of California Irvine, Irvine, California, USA
| | - Xiaohong Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Kun Wu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Jinbao Gu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Guiyun Yan
- Program in Public Health, University of California Irvine, Irvine, California, USA
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China.
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44
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Xu P, Choo YM, Chen Z, Zeng F, Tan K, Chen TY, Cornel AJ, Liu N, Leal WS. Odorant Inhibition in Mosquito Olfaction. iScience 2019; 19:25-38. [PMID: 31349189 PMCID: PMC6660600 DOI: 10.1016/j.isci.2019.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 04/22/2019] [Accepted: 07/03/2019] [Indexed: 01/03/2023] Open
Abstract
How chemical signals are integrated at the peripheral sensory system of insects is still an enigma. Here we show that when coexpressed with Orco in Xenopus oocytes, an odorant receptor from the southern house mosquito, CquiOR32, generated inward (regular) currents when challenged with cyclohexanone and methyl salicylate, whereas eucalyptol and fenchone elicited inhibitory (upward) currents. Responses of CquiOR32-CquiOrco-expressing oocytes to odorants were reduced in a dose-dependent fashion by coapplication of inhibitors. This intrareceptor inhibition was also manifested in vivo in fruit flies expressing the mosquito receptor CquiOR32, as well in neurons on the antennae of the southern house mosquito. Likewise, an orthologue from the yellow fever mosquito, AaegOR71, showed intrareceptor inhibition in the Xenopus oocyte recording system and corresponding inhibition in antennal neurons. Inhibition was also manifested in mosquito behavior. Blood-seeking females were repelled by methyl salicylate, but repellence was significantly reduced when methyl salicylate was coapplied with eucalyptol. We found dual inhibitory/excitatory odorant receptors (ORs) in mosquitoes Inhibitory and endogenous ORs coexpressed in flies showed lateral inhibition The bipolar nature of these inhibitory ORs was displayed in electrophysiology The duality excitation/inhibition was also manifested in mosquito behavior
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Affiliation(s)
- Pingxi Xu
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA 95616, USA
| | - Young-Moo Choo
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA 95616, USA
| | - Zhou Chen
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36489, USA
| | - Fangfang Zeng
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA 95616, USA
| | - Kaiming Tan
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA 95616, USA
| | - Tsung-Yu Chen
- Center for Neuroscience, Department of Neurology, University of California-Davis, Davis, CA 95616, USA
| | - Anthony J Cornel
- Department of Entomology and Nematology, University of California-Davis, Davis, CA 95616, USA
| | - Nannan Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36489, USA
| | - Walter S Leal
- Department of Molecular and Cellular Biology, University of California-Davis, Davis, CA 95616, USA.
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Kepchia D, Xu P, Terryn R, Castro A, Schürer SC, Leal WS, Luetje CW. Use of machine learning to identify novel, behaviorally active antagonists of the insect odorant receptor co-receptor (Orco) subunit. Sci Rep 2019; 9:4055. [PMID: 30858563 PMCID: PMC6411751 DOI: 10.1038/s41598-019-40640-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 02/18/2019] [Indexed: 12/24/2022] Open
Abstract
Olfaction is a key component of the multimodal approach used by mosquitoes to target and feed on humans, spreading various diseases. Current repellents have drawbacks, necessitating development of more effective agents. In addition to variable odorant specificity subunits, all insect odorant receptors (ORs) contain a conserved odorant receptor co-receptor (Orco) subunit which is an attractive target for repellent development. Orco directed antagonists allosterically inhibit odorant activation of ORs and we previously showed that an airborne Orco antagonist could inhibit insect olfactory behavior. Here, we identify novel, volatile Orco antagonists. We functionally screened 83 structurally diverse compounds against Orco from Anopheles gambiae. Results were used for training machine learning models to rank probable activity of a library of 1280 odorant molecules. Functional testing of a representative subset of predicted active compounds revealed enrichment for Orco antagonists, many structurally distinct from previously known Orco antagonists. Novel Orco antagonist 2-tert-butyl-6-methylphenol (BMP) inhibited odorant responses in electroantennogram and single sensillum recordings in adult Drosophila melanogaster and inhibited OR-mediated olfactory behavior in D. melanogaster larvae. Structure-activity analysis of BMP analogs identified compounds with improved potency. Our results provide a new approach to the discovery of behaviorally active Orco antagonists for eventual use as insect repellents/confusants.
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Affiliation(s)
- Devin Kepchia
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, 33136, USA
| | - Pingxi Xu
- Department of Molecular and Cellular Biology, University of California, Davis, CA, 95616, USA
| | - Raymond Terryn
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, 33136, USA.,Center for Computational Science, University of Miami, Coral Gables, FL, 33146, USA
| | - Ana Castro
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, 33136, USA
| | - Stephan C Schürer
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, 33136, USA.,Center for Computational Science, University of Miami, Coral Gables, FL, 33146, USA
| | - Walter S Leal
- Department of Molecular and Cellular Biology, University of California, Davis, CA, 95616, USA
| | - Charles W Luetje
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, 33136, USA.
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Coutinho-Abreu IV, Sharma K, Cui L, Yan G, Ray A. Odorant ligands for the CO 2 receptor in two Anopheles vectors of malaria. Sci Rep 2019; 9:2549. [PMID: 30796292 PMCID: PMC6385339 DOI: 10.1038/s41598-019-39099-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 01/08/2019] [Indexed: 01/01/2023] Open
Abstract
Exhaled CO2 is an important host-seeking cue for Anopheles mosquitoes, which is detected by a highly conserved heteromeric receptor consisting of three 7-transmembrane proteins Gr22, Gr23, and Gr24. The CO2 receptor neuron has been shown to also respond sensitively to a variety of odorants in Aedes aegypti. The detection of CO2 is important for upwind navigation and for enhancing the attraction to body heat as well as to skin odorants. The orthologs of the CO2 receptor proteins are present in malaria-transmitting mosquitoes like Anopheles coluzzii and Anopheles sinensis. Activators and inhibitors of the CO2-neuron were tested on the maxillary palps in these two species by single-sensillum electrophysiology. The electrophysiological testing of three prolonged-activator odorants identified originally in Aedes aegypti also showed varying ability to reduce the CO2-ellicited increase in spikes. These findings provide a foundation for comparing the functional conservation with the evolutionary conservation of an important class of odorant receptor. The identification of a suite of natural odorants that can be used to modify the CO2-detection pathway may also contribute to odor-blends that can alter the behavior of these disease transmitting mosquitoes.
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Affiliation(s)
- Iliano V Coutinho-Abreu
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Kavita Sharma
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA
| | - Liwang Cui
- Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Guiyun Yan
- Public Health and Ecology & Evolution Biology, University of California, Irvine, CA, 92697, USA
| | - Anandasankar Ray
- Department of Molecular Cell and Systems Biology, University of California Riverside, Riverside, CA, 92521, USA.
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Godiya CB, Gabrielli S, Materazzi S, Pianesi MS, Stefanini N, Marcantoni E. Depolymerization of waste poly(methyl methacrylate) scraps and purification of depolymerized products. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 231:1012-1020. [PMID: 30602225 DOI: 10.1016/j.jenvman.2018.10.116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/21/2018] [Accepted: 10/31/2018] [Indexed: 06/09/2023]
Abstract
A big challenge for the civilization in energy saving/waste management can be "the regeneration of monomers from the waste plastics followed by their re-polymerization" using an ideal recycling method. Herein, we investigate the thermal depolymerization of poly(methyl methacrylate) (PMMA) using thermogravimetric analysis coupled with mass spectrometry (TGA-MS). In this process, the polymer chains were decomposed to methyl methacrylate (MMA) in high yield and the degradation species were thoroughly characterized. The obtained MMA contained traces of byproducts. Firstly, the byproducts were found to be nonpolymerizable, secondly, their presence interrupt the polymerization reaction, and thirdly, they reduce the quality of re-polymerized PMMA (r-PMMA). This study reclaims that besides the main byproduct (methyl isobutyrate), traces of methyl pyruvate and 2,3-butanedione were also formed during the thermal depolymerization of PMMA. The formed 2,3-butanedione was found to be responsible for the unpleasant smell in the recovered MMA that also found itself in the r-PMMA. Further, the generated byproducts were eliminated from the r-PMMA by a dissolution/re-precipitation method. The structural characterizations of the recycled and purified PMMA were carried out by Fourier-transform-infrared spectroscopy (FT-IR), Hydrogen-1 (1H)- and Carbon-13 (13C)-nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The chemical properties of the r-PMMA and purified PMMA proved to be similar to that of the virgin commercial PMMA. This study can provide an effective and practical prototype for the recycling of waste PMMA scraps and thus reduction in pollution caused by the landfilling of waste PMMA scraps.
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Affiliation(s)
- Chirag B Godiya
- Chemistry Division, School of Science and Technology, University of Camerino, Via. S. Agostino 1, 62032, Camerino, MC, Italy.
| | - Serena Gabrielli
- Chemistry Division, School of Science and Technology, University of Camerino, Via. S. Agostino 1, 62032, Camerino, MC, Italy
| | - Stefano Materazzi
- Department of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185, Rome, Italy
| | | | - Nicola Stefanini
- Chemistry Division, School of Science and Technology, University of Camerino, Via. S. Agostino 1, 62032, Camerino, MC, Italy
| | - Enrico Marcantoni
- Chemistry Division, School of Science and Technology, University of Camerino, Via. S. Agostino 1, 62032, Camerino, MC, Italy.
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Varela N, Gaspar M, Dias S, Vasconcelos ML. Avoidance response to CO2 in the lateral horn. PLoS Biol 2019; 17:e2006749. [PMID: 30653496 PMCID: PMC6336243 DOI: 10.1371/journal.pbio.2006749] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 12/13/2018] [Indexed: 12/16/2022] Open
Abstract
In flies, the olfactory information is carried from the first relay in the brain, the antennal lobe, to the mushroom body (MB) and the lateral horn (LH). Olfactory associations are formed in the MB. The LH was ascribed a role in innate responses based on the stereotyped connectivity with the antennal lobe, stereotyped physiological responses to odors, and MB silencing experiments. Direct evidence for the functional role of the LH is still missing. Here, we investigate the behavioral role of the LH neurons (LHNs) directly, using the CO2 response as a paradigm. Our results show the involvement of the LH in innate responses. Specifically, we demonstrate that activity in two sets of neurons is required for the full behavioral response to CO2. Tests of the behavioral response to other odors indicate the neurons are selective to CO2 response. Using calcium imaging, we observe that the two sets of neurons respond to CO2 in a different manner. Using independent manipulation and recording of the two sets of neurons, we find that the one that projects to the superior intermediate protocerebrum (SIP) also outputs to the local neurons within the LH. The design of simultaneous output at the LH and the SIP, an output of the MB, allows for coordination between innate and learned responses.
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Affiliation(s)
- Nélia Varela
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Miguel Gaspar
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Sophie Dias
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
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Paskewitz S, Irwin P, Konwinski N, Larson S. Impact of Consumption of Bananas on Attraction of Anopheles stephensi to Humans. INSECTS 2018; 9:insects9040129. [PMID: 30274200 PMCID: PMC6315685 DOI: 10.3390/insects9040129] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/22/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022]
Abstract
Humans vary in attractiveness to mosquitoes, a phenomenon that is largely attributed to differences in physical cues such as heat and volatile odors emanating from breath and skin. Diet can change human odors but whether specific dietary components alter host attractiveness is largely unexplored. We identified bananas as a target for study following a survey of the internet for advice on avoiding mosquito bites. Human attractiveness to Anopheles stephensi Liston was measured using a glass vial bioassay where mosquito contacts were measured before and 1–3 h after ingestion of bananas or grapes. Consumption of grapes had no effect on the number of contacts but banana ingestion resulted in a significant increase in the overall number of contacts in spite of individual variation that included some subjects who showed no effect or decreases in contacts. Further tests with a single volunteer showed that the effect was repeatable and consistent across 15 trials. The magnitude of the increase was not affected by the number of bananas eaten. Increased contact counts after banana ingestion were also observed when A. gambiae Giles was tested. These results support the hypothesis that diet plays an important role in mediating host attractiveness to anopheline mosquitoes.
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Affiliation(s)
- Susan Paskewitz
- Department of Entomology, University of Wisconsin, Madison, WI 53706, USA.
| | - Patrick Irwin
- Department of Entomology, University of Wisconsin, Madison, WI 53706, USA.
| | - Nic Konwinski
- Department of Entomology, University of Wisconsin, Madison, WI 53706, USA.
| | - Scott Larson
- Department of Entomology, University of Wisconsin, Madison, WI 53706, USA.
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Roodt AP, Naudé Y, Stoltz A, Rohwer E. Human skin volatiles: Passive sampling and GC × GC-ToFMS analysis as a tool to investigate the skin microbiome and interactions with anthropophilic mosquito disease vectors. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1097-1098:83-93. [PMID: 30212730 DOI: 10.1016/j.jchromb.2018.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/16/2018] [Accepted: 09/01/2018] [Indexed: 12/18/2022]
Abstract
Volatile organic compounds (VOCs) emanating from the surfaces of human skin are of great interest to researchers in medical and forensic fields, as well as to biologists studying the ecology of blood-feeding insect vectors of human disease. Research involving the comparison of relative abundances of VOCs emanating from human skin is currently limited by the methodology used for sample collection and pre-concentration. The use of in-house developed silicone rubber (polydimethylsiloxane (PDMS)) passive sampling devices constructed in the form of bracelets and anklets was explored to address this need. The easy-to-use samplers were employed as non-invasive passive sampling devices for the non-targeted collection and concentration of volatile human skin emissions prior to thermal desorption thereof coupled with comprehensive gas chromatographic time-of-flight mass spectrometric (GC × GC-TOFMS) analysis. Compounds collected were from a wide range of compound classes. Several compounds, notably cyclic ketones, identified have not been previously reported in skin volatile literature. Comparison of normalized unique mass peak area signals has revealed relative quantitative differences and similarities between the samples collected from two individuals' wrists and as well as between an individual's wrist and ankle. The sampling method was evaluated based on its ability to provide many candidate compounds for potential biomarker discovery. The results show the ability of the new sampling method for augmenting the current knowledge on human skin volatile emissions. The samplers are both easy to use and economical. Applications explored include the study of the complex relationships between the human skin microbiome and the attractiveness of individuals to anthropophilic blood host seeking mosquitoes.
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Affiliation(s)
- Alexis P Roodt
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Yvette Naudé
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa.
| | - Anton Stoltz
- Division of Infectious Diseases, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Egmont Rohwer
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
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