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Popkin-Hall ZR, Slotman MA. The role of the major chemosensory organs in the host-seeking activity of Anopheles coluzzii (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2024; 61:861-868. [PMID: 38733173 DOI: 10.1093/jme/tjae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/30/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024]
Abstract
Anopheles coluzzii (Coetzee & Wilkerson) and its sibling species Anopheles gambiae s.s. (Giles) are highly anthropophilic and among the major malaria vectors in sub-Saharan Africa. Mosquitoes use various senses to find hosts, but rely primarily on olfaction. Therefore, the mosquito olfactory system has been studied extensively, including a variety of studies comparing chemosensory gene expression between An. coluzzii and its zoophilic sibling species Anopheles quadriannulatus (Theobald). These studies revealed species-specific chemosensory gene expression in the antennae and maxillary palps, which raised the question of a potential role for the palps in determining species-specific host preferences. To answer this question, we mechanically ablated the antennae, maxillary palps, and labella, and ran both control and ablated mosquitoes through a dual-port olfactometer. While we aimed to identify the organs responsible for vertebrate host choice, the ablated mosquitoes exclusively responded to human odor, so we were unable to do so. However, we were able to refine our understanding of the roles of these organs in host-seeking activation (leaving the release cage) as well as odor response (entering an odor port). As expected, the antennae are the most important organs to both behaviors: activation was roughly halved and vertebrate odor response was abolished in antennae-ablated mosquitoes. Maxillary palp ablation had little impact on activation, but reduced odor response to a similar degree as the exclusion of CO2. Finally, while labellar ablation dramatically reduced activation (probably associated with the inability to feed), it had little impact on odor response, suggesting that any labellar role in host choice is likely not olfactory.
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Affiliation(s)
| | - Michel A Slotman
- Department of Entomology, Texas A&M University, College Station, TX, USA
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2
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Giraldo D, Hammond AM, Wu J, Feole B, Al-Saloum N, McMeniman CJ. An expanded neurogenetic toolkit to decode olfaction in the African malaria mosquito Anopheles gambiae. CELL REPORTS METHODS 2024; 4:100714. [PMID: 38412833 PMCID: PMC10921037 DOI: 10.1016/j.crmeth.2024.100714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/01/2023] [Accepted: 01/29/2024] [Indexed: 02/29/2024]
Abstract
Anopheles gambiae uses its sense of smell to hunt humans. We report a two-step method yielding cell-type-specific driver lines for enhanced neuroanatomical and functional studies of its olfactory system. We first integrated a driver-responder-marker (DRM) system cassette consisting of a linked T2A-QF2 driver, QUAS-GFP responder, and a gut-specific transgenesis marker into four chemoreceptor genes (Ir25a, Ir76b, Gr22, and orco) using CRISPR-Cas9-mediated homology-directed repair. The DRM system facilitated rapid selection of in-frame integrations via screening for GFP+ olfactory sensory neurons (OSNs) in G1 larval progeny, even at genomic loci such as orco where we found the transgenesis marker was not visible. Next, we converted these DRM integrations into T2A-QF2 driver-marker lines by Cre-loxP excision of the GFP responder, making them suitable for binary use in transcuticular calcium imaging. These cell-type-specific driver lines tiling key OSN subsets will support systematic efforts to decode olfaction in this prolific malaria vector.
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Affiliation(s)
- Diego Giraldo
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Andrew M Hammond
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Life Sciences, Imperial College London, London, UK
| | - Jinling Wu
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Brandon Feole
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Noor Al-Saloum
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Conor J McMeniman
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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3
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Konopka JK, Task D, Poinapen D, Potter CJ. Neurogenetic identification of mosquito sensory neurons. iScience 2023; 26:106690. [PMID: 37182106 PMCID: PMC10172775 DOI: 10.1016/j.isci.2023.106690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/06/2023] [Accepted: 04/13/2023] [Indexed: 05/16/2023] Open
Abstract
Anopheles mosquitoes, as vectors for the malaria parasite, are a global threat to human health. To find and bite a human, they utilize neurons within their sensory appendages. However, the identity and quantification of sensory appendage neurons are lacking. Here we use a neurogenetic approach to label all neurons in Anopheles coluzzii mosquitoes. We utilize the homology assisted CRISPR knock-in (HACK) approach to generate a T2A-QF2w knock-in of the synaptic gene bruchpilot. We use a membrane-targeted GFP reporter to visualize the neurons in the brain and to quantify neurons in all major chemosensory appendages (antenna, maxillary palp, labella, tarsi, and ovipositor). By comparing labeling of brp>GFP and Orco>GFP mosquitoes, we predict the extent of neurons expressing ionotropic receptors (IRs) or other chemosensory receptors. This work introduces a valuable genetic tool for the functional analysis of Anopheles mosquito neurobiology and initiates characterization of the sensory neurons that guide mosquito behavior.
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Affiliation(s)
- Joanna K. Konopka
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Darya Task
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Danny Poinapen
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Christopher J. Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Corresponding author
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4
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Yamany AS, Abdel-Gaber R. Studies on the sensory sensilla on the tarsi and external genitalia of the Asian tiger mosquito, Aedes albopictus (Skuse). Microsc Res Tech 2023; 86:242-251. [PMID: 36398839 DOI: 10.1002/jemt.24264] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/31/2022] [Accepted: 11/09/2022] [Indexed: 11/19/2022]
Abstract
Dengue fever is a worldwide health problem transmitted mainly by Aedes albopictus. The ability of female mosquitoes to transmit disease depends on their behavioral responses to locate their host. The presence of different types of sensory sensilla with different morphological characteristics is the most distinctive feature of Ae. albopictus, in addition to the main sensory organs. The sensory sensilla are chemosensory contacts that Ae. albopictus uses to locate long-distance hosts and oviposition sites by receiving well-defined cues such as changes in temperature and humidity, mechanical impact, and odors. As a result, it is crucial to study the sensory sensilla of Ae. albopictus. Although the sensory sensilla of Ae. aegypti have been extensively studied, but there is still a lack of knowledge about the sensory sensilla of the Asian tiger mosquito, Ae. albopictus. This study aimed to investigate the different types of sensory sensilla on the tarsi and external genitalia of both sexes of Ae. albopictus and their morphological features using a scanning electron microscope. The results demonstrated that the tarsi have five types of sensory sensilla: sensilla chaetica, grooved pegs, sensilla campaniform, sensilla basiconica, and sensilla coeloconica. There are two thick, grooved sensilla on the tarsal joints. Sensilla coeloconica on the tarsus are hidden under scales in a raised pit and have a diameter of 13.69 ± 0.071 μm, which is significantly larger than those on the external genitalia of males, which have a diameter of 7.65 ± 0.065 μm. Sensilla coeloconica is absent from the external genitalia of females. Two types of senillae chaetica are found on the tarsomeres, near the claws, and on the joints, which differ significantly in morphology and morphometric parameters. The ovulation-supporting cerci are provided with three pairs of long sensilla chaetica at the apex, measuring 111.36 ± 0.020 μm in length. Two groups of four apical sensilla and short spiny subapical sensilla are randomly distributed on the ovipositor. The female external genitalia have two types of sensilla chaetica, which are arranged in rows and are significantly smaller than those of the male external genitalia. RESEARCH HIGHLIGHTS: Aedes albopictus showed various sensory structures distributed on the tarsi and genitalia of both sexes. Adequate information is available in this study to understand chemoreception and odor detection by different kinds of sensilla that help to evaluate the ability of female mosquitoes to transmit diseases.
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Affiliation(s)
- Abeer S Yamany
- Zoology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.,Biology Department, Faculty of Science, Hafr Al Batin University, Saudi Arabia
| | - Rewaida Abdel-Gaber
- Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia
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5
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Raji JI, Potter CJ. Chemosensory ionotropic receptors in human host-seeking mosquitoes. CURRENT OPINION IN INSECT SCIENCE 2022; 54:100967. [PMID: 36096415 DOI: 10.1016/j.cois.2022.100967] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/30/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Half the world's human population is at risk for mosquito-borne diseases. Mosquitoes rely mainly on their sense of smell to find a vertebrate blood host, nectar source, and a suitable oviposition site. Advances in neurogenetic tools have now aided our understanding of the receptors that mediate the detection of sensory cues that emanate from humans. Recent studies in the anthropophilic mosquito vectors, Aedes aegypti and Anopheles gambiae, have implicated the chemosensory ionotropic-receptor (IR) family in the detection of behaviorally relevant odors and uncovered functions beyond chemical sensing. Here, we highlight the multifunctional roles of the chemosensory ionotropic receptors in anthropophilic mosquito vectors and suggest future directions to improve our understanding of the IR family.
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Affiliation(s)
- Joshua I Raji
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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6
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Ye Z, Liu F, Sun H, Ferguson ST, Baker A, Ochieng SA, Zwiebel LJ. Discrete roles of Ir76b ionotropic coreceptor impact olfaction, blood feeding, and mating in the malaria vector mosquito Anopheles coluzzii. Proc Natl Acad Sci U S A 2022; 119:e2112385119. [PMID: 35648836 PMCID: PMC9191353 DOI: 10.1073/pnas.2112385119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 04/13/2022] [Indexed: 11/18/2022] Open
Abstract
Anopheline mosquitoes rely on their highly sensitive chemosensory apparatus to detect diverse chemical stimuli that drive the host-seeking and blood-feeding behaviors required to vector pathogens for malaria and other diseases. This process incorporates a variety of chemosensory receptors and transduction pathways. We used advanced in vivo gene-editing and -labeling approaches to localize and functionally characterize the ionotropic coreceptor AcIr76b in the malaria mosquito Anopheles coluzzii, where it impacts both olfactory and gustatory systems. AcIr76b has a broad expression pattern in female adult antennal grooved pegs, coeloconic sensilla, and T1 and T2 sensilla on the labellum, stylets, and tarsi, as well as the larval sensory peg. AcIr76b is colocalized with the Orco odorant receptor (OR) coreceptor in a subset of cells across the female antennae and labella. In contrast to Orco and Ir8a, chemosensory coreceptors that appear essential for the activity of their respective sets of chemosensory neurons in mosquitoes, AcIr76b−/− mutants maintain wild-type peripheral responses to volatile amines on the adult palps, labellum, and larval sensory cone. Interestingly, AcIr76b−/− mutants display significantly increased responses to amines in antennal grooved peg sensilla, while coeloconic sensilla reveal significant deficits in responses to several acids and amines. Behaviorally, AcIr76b mutants manifest significantly female-specific insemination deficits, and although AcIr76b−/− mutant females can locate, alight on, and probe artificial blood hosts, they are incapable of blood feeding successfully. Taken together, our findings reveal a multidimensional functionality of Ir76b in anopheline olfactory and gustatory pathways that directly impacts the vectorial capacity of these mosquitoes.
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Affiliation(s)
- Zi Ye
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Feng Liu
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Huahua Sun
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Stephen T. Ferguson
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Adam Baker
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Samuel A. Ochieng
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
| | - Laurence J. Zwiebel
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235
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Sumner BD, Cardé RT. Primacy of Human Odors Over Visual and Heat Cues in Inducing Landing in Female Aedes aegypti Mosquitoes. JOURNAL OF INSECT BEHAVIOR 2022; 35:31-43. [PMID: 35846381 PMCID: PMC9276619 DOI: 10.1007/s10905-022-09796-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
Although human skin odor is thought to be the cue that anthropophilic mosquitoes use to discriminate us from other potential hosts, the precise details of how they use skin odor to find and land on a human is unclear. We found that Aedes aegypti land on a source of skin odor without a co-located visual cue. By collecting human odor on glass beads and using identical glass beads to visually conceal skin odor and heat cues, we were able to study mosquito landing on skin odor, heat, and visual cues separately. Landing is necessary for blood feeding which is a required behavior for the Aedes aegypti life cycle as well as the behavior responsible for the epidemiological impact of mosquitoes. Therefore, we consider it to be the diagnostic measure of the importance of a host cue. In two-choice tests, a skin odor source had the highest valence for landing, followed by a combination of heat and a visual cue, and finally heat and visual cues presented separately. We also measured the durations of the landings, though no significant differences were found. Supplementary Information The online version contains supplementary material available at 10.1007/s10905-022-09796-2.
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Affiliation(s)
- Benjamin D. Sumner
- Department of Entomology, University of California, Riverside, CA 92521 USA
| | - Ring T. Cardé
- Department of Entomology, University of California, Riverside, CA 92521 USA
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8
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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: 25] [Impact Index Per Article: 12.5] [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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9
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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: 1] [Impact Index Per Article: 0.5] [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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10
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Speth Z, Kaur G, Mazolewski D, Sisomphou R, Siao DDC, Pooraiiouby R, Vasquez-Gross H, Petereit J, Gulia-Nuss M, Mathew D, Nuss AB. Characterization of Anopheles stephensi Odorant Receptor 8, an Abundant Component of the Mouthpart Chemosensory Transcriptome. INSECTS 2021; 12:593. [PMID: 34208911 PMCID: PMC8304465 DOI: 10.3390/insects12070593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/22/2021] [Accepted: 06/26/2021] [Indexed: 01/25/2023]
Abstract
Several mosquito species within the genus Anopheles are vectors for human malaria, and the spread of this disease is driven by the propensity of certain species to feed preferentially on humans. The study of olfaction in mosquitoes is important to understand dynamics of host-seeking and host-selection; however, the majority of these studies focus on Anopheles gambiae or An. coluzzii, both vectors of malaria in Sub-Saharan Africa. Other malaria vectors may recognize different chemical cues from potential hosts; therefore, in this study, we investigated An. stephensi, the south Asian malaria mosquito. We specifically focused on the mouthparts (primarily the maxillary palp and labella) that have been much less investigated compared to the antennae but are also important for host-seeking. To provide a broad view of chemoreceptor expression, RNAseq was used to examine the transcriptomes from the mouthparts of host-seeking females, blood-fed females, and males. Notably, AsOr8 had a high transcript abundance in all transcriptomes and was, therefore, cloned and expressed in the Drosophila empty neuron system. This permitted characterization with a panel of odorants that were selected, in part, for their presence in the human odor profile. The responsiveness of AsOr8 to odorants was highly similar to An. gambiae Or8 (AgOr8), except for sulcatone, which was detected by AsOr8 but not AgOr8. Subtle differences in the receptor sensitivity to specific odorants may provide clues to species- or strain-specific approaches to host-seeking and host selection. Further exploration of the profile of An. stephensi chemosensory proteins may yield a better understanding of how different malaria vectors navigate host-finding and host-choice.
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Affiliation(s)
- Zachary Speth
- Cell and Molecular Biology Graduate Program, University of Nevada, Reno, NV 89557, USA; (Z.S.); (G.K.); (D.M.)
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA; (R.S.); (D.D.C.S.); (R.P.)
| | - Gurlaz Kaur
- Cell and Molecular Biology Graduate Program, University of Nevada, Reno, NV 89557, USA; (Z.S.); (G.K.); (D.M.)
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA; (R.S.); (D.D.C.S.); (R.P.)
| | - Devin Mazolewski
- Cell and Molecular Biology Graduate Program, University of Nevada, Reno, NV 89557, USA; (Z.S.); (G.K.); (D.M.)
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA; (R.S.); (D.D.C.S.); (R.P.)
| | - Rayden Sisomphou
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA; (R.S.); (D.D.C.S.); (R.P.)
| | - Danielle Denise C. Siao
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA; (R.S.); (D.D.C.S.); (R.P.)
| | - Rana Pooraiiouby
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA; (R.S.); (D.D.C.S.); (R.P.)
| | - Hans Vasquez-Gross
- Nevada Bioinformatics Center, University of Nevada, Reno, NV 89557, USA; (H.V.-G.); (J.P.)
| | - Juli Petereit
- Nevada Bioinformatics Center, University of Nevada, Reno, NV 89557, USA; (H.V.-G.); (J.P.)
| | - Monika Gulia-Nuss
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA;
| | - Dennis Mathew
- Department of Biology, University of Nevada, Reno, NV 89557, USA;
| | - Andrew B. Nuss
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA; (R.S.); (D.D.C.S.); (R.P.)
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA;
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11
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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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12
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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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Zamyatin A, Avdeyev P, Liang J, Sharma A, Chen C, Lukyanchikova V, Alexeev N, Tu Z, Alekseyev MA, Sharakhov IV. Chromosome-level genome assemblies of the malaria vectors Anopheles coluzzii and Anopheles arabiensis. Gigascience 2021; 10:giab017. [PMID: 33718948 PMCID: PMC7957348 DOI: 10.1093/gigascience/giab017] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/01/2021] [Accepted: 01/23/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Anopheles coluzzii and Anopheles arabiensis belong to the Anopheles gambiae complex and are among the major malaria vectors in sub-Saharan Africa. However, chromosome-level reference genome assemblies are still lacking for these medically important mosquito species. FINDINGS In this study, we produced de novo chromosome-level genome assemblies for A. coluzzii and A. arabiensis using the long-read Oxford Nanopore sequencing technology and the Hi-C scaffolding approach. We obtained 273.4 and 256.8 Mb of the total assemblies for A. coluzzii and A. arabiensis, respectively. Each assembly consists of 3 chromosome-scale scaffolds (X, 2, 3), complete mitochondrion, and unordered contigs identified as autosomal pericentromeric DNA, X pericentromeric DNA, and Y sequences. Comparison of these assemblies with the existing assemblies for these species demonstrated that we obtained improved reference-quality genomes. The new assemblies allowed us to identify genomic coordinates for the breakpoint regions of fixed and polymorphic chromosomal inversions in A. coluzzii and A. arabiensis. CONCLUSION The new chromosome-level assemblies will facilitate functional and population genomic studies in A. coluzzii and A. arabiensis. The presented assembly pipeline will accelerate progress toward creating high-quality genome references for other disease vectors.
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Affiliation(s)
- Anton Zamyatin
- Computer Technologies Laboratory, ITMO University, Kronverkskiy Prospekt 49-A, Saint Petersburg 197101, Russia
| | - Pavel Avdeyev
- Department of Mathematics, The George Washington University, 801 22nd Street NW, Washington, DC 20052, USA
- Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA
| | - Jiangtao Liang
- Department of Entomology, Virginia Polytechnic Institute and State University, 170 Drillfield Drive, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
| | - Atashi Sharma
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Chujia Chen
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Varvara Lukyanchikova
- Department of Entomology, Virginia Polytechnic Institute and State University, 170 Drillfield Drive, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Institute of Cytology and Genetics the Siberian Division of the Russian Academy of Sciences, Prospekt Lavrentyeva 10, Novosibirsk 630090, Russia
| | - Nikita Alexeev
- Computer Technologies Laboratory, ITMO University, Kronverkskiy Prospekt 49-A, Saint Petersburg 197101, Russia
| | - Zhijian Tu
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Max A Alekseyev
- Department of Mathematics, The George Washington University, 801 22nd Street NW, Washington, DC 20052, USA
- Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, 800 22nd Street NW, Washington, DC 20052, USA
| | - Igor V Sharakhov
- Department of Entomology, Virginia Polytechnic Institute and State University, 170 Drillfield Drive, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
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14
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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: 24] [Impact Index Per Article: 8.0] [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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15
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Mwingira V, Mboera LEG, Dicke M, Takken W. Exploiting the chemical ecology of mosquito oviposition behavior in mosquito surveillance and control: a review. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2020; 45:155-179. [PMID: 33207066 DOI: 10.1111/jvec.12387] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Vector control is an important component of the interventions aimed at mosquito-borne disease control. Current and future mosquito control strategies are likely to rely largely on the understanding of the behavior of the vector, by exploiting mosquito biology and behavior, while using cost-effective, carefully timed larvicidal and high-impact, low-volume adulticidal applications. Here we review the knowledge on the ecology of mosquito oviposition behavior with emphasis on the potential role of infochemicals in surveillance and control of mosquito-borne diseases. A search of PubMed, Embase, Web of Science, Global Health Archive, and Google Scholar databases was conducted using the keywords mosquito, infochemical, pheromone, kairomone, allomone, synomone, apneumone, attractant, host-seeking, and oviposition. Articles in English from 1974 to 2019 were reviewed to gain comprehensive understanding of current knowledge on infochemicals in mosquito resource-searching behavior. Oviposition of many mosquito species is mediated by infochemicals that comprise pheromones, kairomones, synomones, allomones, and apneumones. The novel putative infochemicals that mediate oviposition in the mosquito subfamilies Anophelinae and Culicinae were identified. The role of infochemicals in surveillance and control of these and other mosquito tribes is discussed with respect to origin of the chemical cues and how these affect gravid mosquitoes. Oviposition attractants and deterrents can potentially be used for manipulation of mosquito behavior by making protected resources unsuitable for mosquitoes (push) while luring them towards attractive sources (pull). In this review, strategies of targeting breeding sites with environmentally friendly larvicides with the aim to develop appropriate trap-and-kill techniques are discussed.
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Affiliation(s)
- Victor Mwingira
- Laboratory of Entomology, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
- National Institute for Medical Research, Amani Research Centre, P.O. Box 81, Muheza, Tanzania
| | - Leonard E G Mboera
- SACIDS Foundation for One Health, Sokoine University of Agriculture, P.O. Box 3297 Chuo Kikuu, Morogoro, Tanzania
| | - Marcel Dicke
- Laboratory of Entomology, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
| | - Willem Takken
- Laboratory of Entomology, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
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16
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Sun H, Liu F, Ye Z, Baker A, Zwiebel LJ. Mutagenesis of the orco odorant receptor co-receptor impairs olfactory function in the malaria vector Anopheles coluzzii. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 127:103497. [PMID: 33188923 PMCID: PMC7718783 DOI: 10.1016/j.ibmb.2020.103497] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/25/2020] [Accepted: 10/30/2020] [Indexed: 05/04/2023]
Abstract
Mosquitoes rely heavily on their olfactory systems for host seeking, selection of oviposition sites, and avoiding predators and other environmental dangers. Of these behaviors, the preferential selection of a human blood-meal host drives the vectorial capacity of anthropophilic female Anopheles coluzzii mosquitoes. Olfactory receptor neurons (ORNs) are dispersed across several appendages on the head and express an obligate odorant receptor co-receptor (Orco) coupled with a "tuning" odorant receptor (OR) to form heteromeric, odor-gated ion channels in the membrane of these neurons. To examine the mechanistic and functional contributions of Orco/OR complexes to the chemosensory processes of An. coluzzii, we utilized CRISPR/Cas9 gene editing to create a line of homozygous, Orco-knockout, mutant mosquitoes. As expected, orco-/- ORNs across both adult and larval stages of An. coluzzii display significantly lower background activity and lack nearly all odor-evoked responses. In addition, blood-meal-seeking, adult female, orco-/- mutant mosquitoes exhibit severely reduced attraction to human- and non-human-derived odors while gravid females are significantly less responsive to established oviposition attractants. These results reinforce observations in other insects that Orco is crucial in maintaining the activity of ORNs. In that light, it significantly influences a range of olfactory-driven behaviors central to the anthropophilic host preference that is critical to the vectorial capacity of An. coluzzii as a primary vector for human malaria.
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Affiliation(s)
- Huahua Sun
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN, 37235, USA
| | - 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
| | - Laurence J Zwiebel
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN, 37235, USA.
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17
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Ye Z, Liu F, Sun H, Barker M, Pitts RJ, Zwiebel LJ. Heterogeneous expression of the ammonium transporter AgAmt in chemosensory appendages of the malaria vector, Anopheles gambiae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 120:103360. [PMID: 32126276 PMCID: PMC7161093 DOI: 10.1016/j.ibmb.2020.103360] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 05/03/2023]
Abstract
Ammonia is one of the principal kairomones originating from human and other animal emanations and in that context, plays an essential role in the host-seeking behaviors of the malaria vector mosquito Anopheles gambiae. Nevertheless, despite its importance in directing host-seeking, the mechanisms underlying ammonia detection in the mosquito olfactory system remains largely unknown. In addition to ongoing efforts to identify and characterize the molecular receptors that underlie ammonia sensitivity, previous studies have revealed a prominent role for ammonium transporters (Amt) in modulating antennal and behavioral responses in Drosophila melanogaster and An. gambiae. In the former, localization of DmAmt in antennal sensilla to auxiliary cells surrounding the ammonia sensory neurons led to the hypothesis that its role was to clear excess ammonium ions in the sensillar lymph. In the latter, RT-PCR and heterologous expression have been used to examine the expression and functional characteristics of the An. gambiae ammonium transporter, AgAmt. We now employ advanced transgenic tools to comprehensively examine AgAmt spatial localization across the peripheral chemosensory appendages in larvae and adult female An. gambiae. In the larval antennae, AgAmt appears localized in both neuronal and auxiliary cells. In contrast to D. melanogaster, in the adult antennae, AgAmt-derived signals are observed in both non-neuronal auxiliary cells and in sensory neurons in ammonia-responsive basiconic and coeloconic sensilla. In the maxillary palps, labella, and tarsi, AgAmt appears restricted to sensory neurons. We have also characterized the responses to ammonia of adult antennal coeloconic sensilla and maxillary palp capitate pegs revealing a correlation between sensillar AgAmt expression and ammonia sensitivity. Taken together, these data suggest that AgAmt may play heterogeneous roles in the adult and larval chemosensory apparatus and potentially broad utility as a supra-receptor target in mosquito control.
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Affiliation(s)
- Zi Ye
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA
| | - Feng Liu
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA
| | - Huahua Sun
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA
| | | | - R Jason Pitts
- Department of Biology, Baylor University, Waco, TX, 76706, USA
| | - Laurence J Zwiebel
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37235, USA.
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18
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Athrey G, Popkin-Hall Z, Cosme LV, Takken W, Slotman MA. Species and sex-specific chemosensory gene expression in Anopheles coluzzii and An. quadriannulatus antennae. Parasit Vectors 2020; 13:212. [PMID: 32321556 PMCID: PMC7178735 DOI: 10.1186/s13071-020-04085-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 04/15/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Olfactory cues drive mosquito behaviors such as host-seeking, locating sugar sources and oviposition. These behaviors can vary between sexes and closely related species. For example, the malaria vector Anopheles coluzzii is highly anthropophilic, whereas An. quadriannulatus is not. These behavioral differences may be reflected in chemosensory gene expression. METHODS The expression of chemosensory genes in the antennae of both sexes of An. coluzzii and An. quadriannulatus was compared using RNA-seq. The sex-biased expression of several genes in An. coluzzii was also compared using qPCR. RESULTS The chemosensory expression is mostly similar in the male antennae of An. coluzzii and An. quadriannulatus, with only a few modest differences in expression. A handful of chemosensory genes are male-biased in both species; the highly expressed gustatory receptor AgGr33, odorant binding proteins AgObp25, AgObp26 and possibly AgObp10. Although the chemosensory gene repertoire is mostly shared between the sexes, several highly female-biased AgOrs, AgIrs, and one AgObp were identified, including several whose expression is biased towards the anthropophilic An. coluzzii. Additionally, the expression of several chemosensory genes is biased towards An. coluzzii in both sexes. CONCLUSIONS Chemosensory gene expression is broadly similar between species and sexes, but several sex- biased/specific genes were identified. These may modulate sex- and species-specific behaviors. Although the male behavior of these species remains poorly studied, the identification of sex- and species-specific chemosensory genes may provide fertile ground for future work.
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Affiliation(s)
- Giridhar Athrey
- Department of Poultry Science, Texas A&M University, College Station, TX USA
| | | | - Luciano Veiga Cosme
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT USA
| | - Willem Takken
- Laboratory of Entomology, Wageningen University and Research, Wageningen, The Netherlands
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19
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Huff RM, Pitts RJ. An odorant receptor from Anopheles gambiae that demonstrates enantioselectivity to the plant volatile, linalool. PLoS One 2019; 14:e0225637. [PMID: 31751420 PMCID: PMC6872167 DOI: 10.1371/journal.pone.0225637] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/29/2019] [Indexed: 02/07/2023] Open
Abstract
Insects express chemical receptors within sensory neurons that are activated by specific cues in the environment, thereby influencing the acquisition of critical resources. A significant gap in our current understanding of insect chemical ecology is defining the molecular mechanisms that underlie sensitivity to plant-emitted volatiles. Linalool is a commonly-occurring monoterpene that has various effects on insect behavior, either acting as an attractant or a repellent, and existing in nature as one of two possible stereoisomers, (R)-(-)-linalool and (S)-(+)-linalool. In this study, we have used a cell-based functional assay to identify linalool and structurally-related compounds as ligands of Odorant receptor 29, a labellum-expressed receptor in the malaria vector mosquito, Anopheles gambiae (AgamOr29). While (R)-(-)-linalool activates AgamOr29, a mixture of the (R) and (S) stereoisomers activates the receptor with higher potency, implying enantiomeric selectivity. Orthologs of Or29 are present in the genomes of Anophelines within the Cellia subgenus. The conservation of this receptor across Anopheline lineages suggests that this ecologically important compound might serve as an attraction cue for nectar-seeking mosquitoes. Moreover, the characterization of a mosquito terpene receptor could serve as a foundation for future ligand-receptor studies of plant volatiles and for the discovery of compounds that can be integrated into push-pull vector control strategies.
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Affiliation(s)
- Robert Mark Huff
- Department of Biology, Baylor University, Waco, Texas, United States of America
| | - R. Jason Pitts
- Department of Biology, Baylor University, Waco, Texas, United States of America
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20
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Afify A, Betz JF, Riabinina O, Lahondère C, Potter CJ. Commonly Used Insect Repellents Hide Human Odors from Anopheles Mosquitoes. Curr Biol 2019; 29:3669-3680.e5. [PMID: 31630950 DOI: 10.1016/j.cub.2019.09.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 07/01/2019] [Accepted: 09/04/2019] [Indexed: 12/26/2022]
Abstract
The mode of action for most mosquito repellents is unknown. This is primarily due to the difficulty in monitoring how the mosquito olfactory system responds to repellent odors. Here, we used the Q-system of binary expression to enable activity-dependent Ca2+ imaging in olfactory neurons of the African malaria mosquito Anopheles coluzzii. This system allows neuronal responses to common insect repellents to be directly visualized in living mosquitoes from all olfactory organs, including the antenna. The synthetic repellents N,N-diethyl-meta-toluamide (DEET) and IR3535 did not activate Anopheles odorant receptor co-receptor (Orco)-expressing olfactory receptor neurons (ORNs) at any concentration, and picaridin weakly activated ORNs only at high concentrations. In contrast, natural repellents (i.e. lemongrass oil and eugenol) strongly activated small numbers of ORNs in the Anopheles mosquito antennae at low concentrations. We determined that DEET, IR3535, and picaridin decrease the response of Orco-expressing ORNs when these repellents are physically mixed with activating human-derived odorants. We present evidence that synthetic repellents may primarily exert their olfactory mode of action by decreasing the amount of volatile odorants reaching ORNs. These results suggest that synthetic repellents disruptively change the chemical profile of host scent signatures on the skin surface, rendering humans invisible to Anopheles mosquitoes.
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Affiliation(s)
- Ali Afify
- The Solomon H. Snyder Department of Neuroscience, The Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joshua F Betz
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Olena Riabinina
- The Solomon H. Snyder Department of Neuroscience, The Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chloé Lahondère
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, The Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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21
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Ruzzante L, Reijnders MJ, Waterhouse RM. Of Genes and Genomes: Mosquito Evolution and Diversity. Trends Parasitol 2019; 35:32-51. [DOI: 10.1016/j.pt.2018.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/07/2018] [Accepted: 10/08/2018] [Indexed: 12/16/2022]
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