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Lorenzo MG, Fernandes GDR, Latorre-Estivalis JM. Local age-dependent neuromodulation in Rhodnius prolixus antennae. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 115:e22106. [PMID: 38597092 DOI: 10.1002/arch.22106] [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: 02/12/2024] [Revised: 03/12/2024] [Accepted: 03/15/2024] [Indexed: 04/11/2024]
Abstract
Kissing bugs do not respond to host cues when recently molted and only exhibit robust host-seeking several days after ecdysis. Behavioral plasticity has peripheral correlates in antennal gene expression changes through the week after ecdysis. The mechanisms regulating these peripheral changes are still unknown, but neuropeptide, G-protein coupled receptor, nuclear receptor, and takeout genes likely modulate peripheral sensory physiology. We evaluated their expression in antennal transcriptomes along the first week postecdysis of Rhodnius prolixus 5th instar larvae. Besides, we performed clustering and co-expression analyses to reveal relationships between neuromodulatory (NM) and sensory genes. Significant changes in transcript abundance were detected for 50 NM genes. We identified 73 sensory-related and NM genes that were assigned to nine clusters. According to their expression patterns, clusters were classified into four groups: two including genes up or downregulated immediately after ecdysis; and two with genes with expression altered at day 2. Several NM genes together with sensory genes belong to the first group, suggesting functional interactions. Co-expression network analysis revealed a set of genes that seem to connect with sensory system maturation. Significant expression changes in NM components were described in the antennae of R. prolixus after ecdysis, suggesting that a local NM system acts on antennal physiology. These changes may modify the sensitivity of kissing bugs to host cues during this maturation interval.
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Affiliation(s)
- Marcelo Gustavo Lorenzo
- Instituto de Investigaciones en Biodiversidad y Biotecnología, CONICET, Mar del Plata, Buenos Aires, Argentina
- Vector Behaviour and Pathogen Interaction Group, Instituto René Rachou-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | | | - Jose Manuel Latorre-Estivalis
- Laboratorio de Insectos Sociales, Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires-CONICET, Buenos Aires, Argentina
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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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Hinze A, Pelletier J, Ghaninia M, Marois E, Hill SR, Ignell R. Knockout of OR39 reveals redundancy in the olfactory pathway regulating the acquisition of host seeking in Anopheles coluzzii. Proc Biol Sci 2023; 290:20232092. [PMID: 38018099 PMCID: PMC10685123 DOI: 10.1098/rspb.2023.2092] [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: 09/14/2023] [Accepted: 11/06/2023] [Indexed: 11/30/2023] Open
Abstract
The attraction of anthropophilic mosquitoes to human host cues, such as body odour and carbon dioxide, gradually increases during adult maturation. This acquisition of host-seeking behaviour correlates with age-dependent changes in odorant receptor (OR) transcript abundance and sensitivity of olfactory sensory neurons (OSNs). One OR gene of the human malaria vector, Anopheles coluzzii, AcolOR39, is significantly downregulated in mature females, and a cognate ligand of AcolOR39, sulcatone, a major component of human emanations, mediates the observed behavioural inhibition of newly emerged (teneral) females to human body odour. Knockout of AcolOR39, using CRISPR-Cas9 mutagenesis, selectively abolished sulcatone detection in OSNs, housed in trichoid sensilla. However, knockout of AcolOR39 altered neither the response rate nor the flight behaviour of teneral females in a wind tunnel, indicating the involvement of other genes, and thus a redundancy, in regulating the acquisition of host seeking in mosquitoes.
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Affiliation(s)
- Annika Hinze
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
| | - Julien Pelletier
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
| | - Majid Ghaninia
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Eric Marois
- Inserm, CNRS, Université de Strasbourg, Strasbourg 67070, France
| | - Sharon Rose Hill
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
| | - Rickard Ignell
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp 750 07, Sweden
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Pelletier J, Dawit M, Ghaninia M, Marois E, Ignell R. A mosquito-specific antennal protein is critical for the attraction to human odor in the malaria vector Anopheles gambiae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 159:103988. [PMID: 37437853 DOI: 10.1016/j.ibmb.2023.103988] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/21/2023] [Accepted: 07/08/2023] [Indexed: 07/14/2023]
Abstract
Mosquitoes rely mainly on the sense of smell to decipher their environment and locate suitable food sources, hosts for blood feeding and oviposition sites. The molecular bases of olfaction involve multigenic families of olfactory proteins that have evolved to interact with a narrow set of odorants that are critical for survival. Understanding the complex interplay between diversified repertoires of olfactory proteins and ecologically-relevant odorant signals, which elicit important behaviors, is fundamental for the design of novel control strategies targeting the sense of smell of disease vector mosquitoes. Previously, large multigene families of odorant receptor and ionotropic receptor proteins, as well as a subset of odorant-binding proteins have been shown to mediate the selectivity and sensitivity of the mosquito olfactory system. In this study, we identify a mosquito-specific antennal protein (MSAP) gene as a novel molecular actor of odorant reception. MSAP is highly conserved across mosquito species and is transcribed at an extremely high level in female antennae. In order to understand its role in the mosquito olfactory system, we generated knockout mutant lines in Anopheles gambiae, and performed comparative analysis of behavioral and physiological responses to human-associated odorants. We found that MSAP promotes female mosquito attraction to human odor and enhances the sensitivity of the antennae to a variety of odorants. These findings suggest that MSAP is an important component of the mosquito olfactory system, which until now has gone completely unnoticed.
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Affiliation(s)
- Julien Pelletier
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
| | - Mengistu Dawit
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | | | - Eric Marois
- INSERM U1257, CNRS UPR9022, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Rickard Ignell
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
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VanderGiessen M, Tallon AK, Damico B, Lahondère C, Vinauger C. Soap application alters mosquito-host interactions. iScience 2023; 26:106667. [PMID: 37250308 PMCID: PMC10214466 DOI: 10.1016/j.isci.2023.106667] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/17/2023] [Accepted: 04/11/2023] [Indexed: 05/31/2023] Open
Abstract
To find nutrients, mosquitoes use volatile organic compounds (VOCs) emitted by plants and animal hosts. These resources overlap in their chemical composition, and an important layer of information resides in VOCs' relative abundance in the headspace of each resource. In addition, a large majority of the human species regularly uses personal care products such as soaps and perfumes, which add plant-related VOCs to their olfactory signature. Using headspace sampling and gas chromatography-mass spectrometry, we quantified how human odor is modified by soap application. We showed that soaps alter mosquito host selection, with some soaps increasing the attractiveness of the host and some soaps reducing it. Analytical methods revealed the main chemicals associated with these changes. These results provide proof-of-concept that data on host-soap valences can be reverse-engineered to produce chemical blends for artificial baits or mosquito repellents, and evince the impact of personal care products on host selection processes.
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Affiliation(s)
- Morgen VanderGiessen
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Anaïs K. Tallon
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Bryn Damico
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Chloé Lahondère
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- The Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- The Global Change Center, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens (CeZAP), Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Clément Vinauger
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- The Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens (CeZAP), Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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Raji JI, Konopka JK, Potter CJ. A spatial map of antennal-expressed ionotropic receptors in the malaria mosquito. Cell Rep 2023; 42:112101. [PMID: 36773296 PMCID: PMC10412736 DOI: 10.1016/j.celrep.2023.112101] [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: 10/04/2022] [Revised: 12/22/2022] [Accepted: 01/26/2023] [Indexed: 02/12/2023] Open
Abstract
The mosquito's antenna represents its main olfactory appendage for detecting volatile chemical cues from the environment. Whole-mount fluorescence in situ hybridization of ionotropic receptors (IRs) expressed in the antennae reveals that the antenna might be divisible into proximal and distal functional domains. The number of IR-positive cells appear stereotyped within each antennal segment (flagellomere). Highly expressed odor-tuning IRs exhibit distinct co-localization patterns with the IR coreceptors Ir8a, Ir25a, and Ir76b that might predict their functional properties. Genetic knockin and in vivo functional imaging of IR41c-expressing neurons indicate both odor-induced activation and inhibition in response to select amine compounds. Targeted mutagenesis of IR41c does not abolish behavioral responses to the amine compounds. Our study provides a comprehensive map of IR-expressing neurons in the main olfactory appendage of mosquitoes. These findings show organizing principles of Anopheles IR-expressing neurons, which might underlie their functional contribution to the detection of behaviorally relevant odors.
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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
| | - Joanna K Konopka
- 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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Mosquito host-seeking diel rhythm and chemosensory gene expression is affected by age and Plasmodium stages. Sci Rep 2022; 12:18814. [PMID: 36335172 PMCID: PMC9637142 DOI: 10.1038/s41598-022-23529-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Malaria parasites can affect vector-related behaviours, increasing transmission success. Using Anopheles gambiae and Plasmodium falciparum, we consider the effect of interaction between infection stage and vector age on diel locomotion in response to human odour and the expression of antennal chemosensory genes. We identified age-dependent behavioural diel compartmentalisation by uninfected females post-blood meal. Infection disrupts overall and diel activity patterns compared with age-matched controls. In this study, mosquitoes carrying transmissible sporozoites were more active, shifting activity periods which corresponded with human host availability, in response to human odour. Older, uninfected, blood-fed females displayed reduced activity during their peak host-seeking period in response to human odour. Age- and infection stage-specific changes in odour-mediated locomotion coincide with altered transcript abundance of select chemosensory genes suggesting a possible molecular mechanism regulating the behaviour. We hypothesize that vector-related behaviours of female mosquitoes are altered by infection stage and further modulated by the age post-blood meal of the vector. Findings may have important implications for malaria transmission and disease dynamics.
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Behavioral responses of sand fly Nyssomyia neivai (Psychodidae: Phlebotominae) to 1-hexanol and light. Acta Trop 2022; 236:106680. [PMID: 36087769 DOI: 10.1016/j.actatropica.2022.106680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 11/20/2022]
Abstract
BACKGROUND The search for attractive baits that may facilitate the capture of haematophagous insects has been epidemiologically relevant. Sand flies use chemical cues in different phases of their life cycles to find carbohydrate meals, mates, blood meals and oviposition sites. Few studies have related the behaviours of sand flies with volatile compounds that can influence their life cycles. Previous studies in our laboratory have shown that 1-hexanol released on filter paper is a good attractant for the sand fly Nyssomyia neivai, which is suspected in the transmission of the aetiologic agent of American cutaneous leishmaniasis. METHODS In this study, we developed two release systems to modulated 1-hexanol release: system 1 contained gellan gum and pectin (4:1 ratio), 3% aluminium chloride and 1% glutaraldehyde; system 2 contained: gellan gum and pectin (4:1 ratio) and 3% aluminium chloride. After addition of 1-hexanol to each release system, trials were performed in a wind tunnel with Ny. neivai males and females (unfed, blood-fed and gravid) to evaluate activation and attraction responses. RESULTS Males and unfed females showed the same response pattern to the systems. For both systems, the males and unfed females of the sand flies showed an activation response up to 24 h. The number of responsive gravid females was lower than unfed females for both systems. The blood-fed females showed no responses in any of the release systems. CONCLUSIONS Our findings indicate that the state of the females (unfed, fed and gravid) can interfere with the sand fly responses to volatile compounds. Additionally, both systems evaluated with the compound showed effectiveness for sand fly attraction.
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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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Santos SA, Romão TP, Helvecio E, Barbosa RMR, Leal WS, Ayres CFJ. Elevated expression of odorant receptors and odorant-binding proteins genes detected in antennae of Culex quinquefasciatus field females. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.874727] [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
Culex quinquefasciatus is responsible for the transmission of filarial worms and several arboviruses. Olfaction plays a crucial role in disease transmission as it influences behaviors that are essential for the survival and reproduction of the mosquito, such as the host-seeking behavior, courtship, and oviposition. Understanding the molecular events that coordinate how mosquitoes find their host may lead to alternative methods to reduce diseases transmission. Our aim was to investigate the differential expression profile of odorant receptor (ORs) and odorant-binding proteins (OBPs) genes in Cx. quinquefasciatus field females compared with CqSLab laboratory mosquito colony. Seventeen genes of interest were evaluated for their qualitative and specific expression by RT-PCR on RNAs extracted from female antennae, female legs, complete male bodies, incomplete female bodies (no head and no legs), and L4 larvae. The general expression mapping of olfactory genes revealed that all analyzed genes were expressed in antennae. Some genes showed different qualitative expression profiles, such as CquiOR2, CquiOR64, CquiOR93, CquiOBP11, and CquiOBP16, which were expressed exclusively in female antennae. On the other hand, CquiOR37, CquiOBP2, and CquiOBP43 are expressed in all sample types, and CquiOBP10 was expressed in female antennae and legs and in the complete male bodies. The expression of CquiOBP5 was detected in the female’s antennae and body, but it was absent in the legs. The quantitative differential expression analysis of six of the 17 genes by RT-qPCR was performed from RNA samples from antenna pools collected in three physiological states, post-emergence, post-mating, and post-blood feeding of the field females and CqSLab. A total of 3,600 antennae were analyzed, in pools containing 100 pairs. Most genes screened showed a higher expression level in field mosquitoes when compared with the laboratory strain CqSLab. The expression of CquiOBP5 and CquiOBP10 genes was significantly different between the post-mating and post blood-meal samples of laboratory females (p < 0.05). Our results suggest specialization of the function of the genes studied and divergence in the expression pattern of field mosquitoes compared with laboratory mosquitoes, and therefore, caution should be exercised in the interpretation of data from laboratory mosquito studies.
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Comparisons of chemosensory gene repertoires in human and non-human feeding Anopheles mosquitoes link olfactory genes to anthropophily. iScience 2022; 25:104521. [PMID: 35754720 PMCID: PMC9213756 DOI: 10.1016/j.isci.2022.104521] [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: 12/09/2021] [Revised: 05/08/2022] [Accepted: 05/30/2022] [Indexed: 11/06/2022] Open
Abstract
We investigate the genetic basis of anthropophily (human host use) in a non-model mosquito species group, the Anopheles farauti complex from the southwest Pacific. This complex has experienced multiple transitions from anthropophily to zoophily, contrasting with well-studied systems (the global species Aedes aegypti and the African Anopheles gambiae complex) that have evolved to be specialist anthropophiles. By performing tests of selection and assessing evolutionary patterns for >200 olfactory genes from nine genomes, we identify several candidate genes associated with differences in anthropophily in this complex. Based on evolutionary patterns (phylogenetic relationships, fixed amino acid differences, and structural differences) as well as results from selection analyses, we identify numerous genes that are likely to play an important role in mosquitoes’ ability to detect humans as hosts. Our findings contribute to the understanding of the evolution of insect olfactory gene families and mosquito host preference as well as having potential applied outcomes. Genomes of Anopheles mosquitoes with differing host preferences were sequenced Evolutionary comparisons were performed on >200 insect chemosensory genes These comparisons revealed candidate genes involved in human feeding Two of the main candidates identified were co-receptor Ir8a and Or75
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Odorant-receptor-mediated regulation of chemosensory gene expression in the malaria mosquito Anopheles gambiae. Cell Rep 2022; 38:110494. [PMID: 35263579 PMCID: PMC8957105 DOI: 10.1016/j.celrep.2022.110494] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/03/2022] [Accepted: 02/14/2022] [Indexed: 01/07/2023] Open
Abstract
Mosquitoes locate and approach humans based on the activity of odorant receptors (ORs) expressed on olfactory receptor neurons (ORNs). Olfactogenetic experiments in Anopheles gambiae mosquitoes revealed that the ectopic expression of an AgOR (AgOR2) in ORNs dampened the activity of the expressing neuron. This contrasts with studies in Drosophila melanogaster in which the ectopic expression of non-native ORs in ORNs confers ectopic neuronal responses without interfering with native olfactory physiology. RNA-seq analyses comparing wild-type antennae to those ectopically expressing AgOR2 in ORNs indicated that nearly all AgOR transcripts were significantly downregulated (except for AgOR2). Additional experiments suggest that AgOR2 protein rather than mRNA mediates this downregulation. Using in situ hybridization, we find that AgOR gene choice is active into adulthood and that AgOR2 expression inhibits AgORs from turning on at this late stage. Our study shows that the ORNs of Anopheles mosquitoes (in contrast to Drosophila) are sensitive to a currently unexplored mechanism of AgOR regulation. Maguire et al. discover that the ectopic expression of an olfactory receptor can downregulate the transcription of endogenous odorant receptors in mosquito olfactory neurons. The onset of mosquito odorant-receptor expression by an olfactory neuron continues into adult stages, and is particularly sensitive to exogenous olfactory reception expression.
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Shan S, Song X, Khashaveh A, Wang SN, Lu ZY, Hussain Dhiloo K, Li RJ, Zhang YJ. A female-biased odorant receptor tuned to the lepidopteran sex pheromone in parasitoid Microplitis mediator guiding habitat of host insects. J Adv Res 2022; 43:1-12. [PMID: 36585100 PMCID: PMC9811332 DOI: 10.1016/j.jare.2022.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 02/12/2022] [Accepted: 03/04/2022] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION The parasitoid wasp Microplitis mediator is an important natural enemy of the turnip moth Agrotis segetum and other Noctuidae pests. In our field observation, it was fortuitously discovered that sex pheromone traps used for A. segetum also attract female wasps, verified by a simulated field condition dual-choice laboratory assay. Therefore, it was hypothesized that olfactory recognition could be crucial in this process. In this regard, a female-biased odorant receptor of the wasp, MmedOR49, attracted our attention. OBJECTIVES To unravel the significance of the female-biased MmedOR49 regulating host pheromone recognition. METHODS Expression analysis (fluorescence in situ hybridization; quantitative realtime PCR), in vitro (two-electrode voltage-clamp recordings) and in vivo (RNAi combined with behavioral assessments) functional studies, and bioinformatics (structural modeling and molecular docking) were carried out to investigate the characteristics of MmedOR49. RESULTS MmedOR49 expression was detected in the antennae of females by FISH. Quantification indicated that the expression level of MmedOR49 increased significantly after adult emergence. In vitro functional study revealed that MmedOR49 was specifically tuned to cis-5-decenyl acetate (Z5-10:Ac), the major sex pheromone component of A. segetum. Molecular docking showed that Z5-10:Ac strongly bound to the key amino acid residues His 80, Ile 81, and Arg 84 of MmedOR49 through hydrogen bonding. Behavioral assays indicated that female wasps were significantly attracted by Z5-10:Ac in a three-cage olfactometer. RNAi targeting further confirmed that MmedOR49 was necessary to recognize Z5-10:Ac, as female wasps lost their original behavioral responses to Z5-10:Ac after down-regulation of the MmedOR49 transcript. CONCLUSION Although M. mediator is a larval endoparasitoid, female wasps have a behavioral preference for a sex pheromone component of lepidopteran hosts. In this behavior, for female M. mediator, MmedOR49 plays an important role in guiding the habitat of host insects. These data provide a potential target for enhancing natural enemy utilization and pest control.
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Affiliation(s)
- Shuang Shan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xuan Song
- College of Plant Protection, Agricultural University of Hebei, Baoding 071000, China,College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Adel Khashaveh
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Shan-Ning Wang
- Institute of Plant and Environment Protection, Beijing Academy of Agricultural and Forestry Sciences, Beijing 100097, China
| | - Zi-Yun Lu
- IPM Center of Hebei Province, Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Plant Protection Institute, Hebei Academy of Agricultural and Forestry Sciences, Baoding 071000, China
| | - Khalid Hussain Dhiloo
- Department of Entomology, Faculty of Crop Protection, Sindh Agriculture University, Tandojam 70060, Pakistan
| | - Rui-Jun Li
- College of Plant Protection, Agricultural University of Hebei, Baoding 071000, China
| | - Yong-Jun Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China,Corresponding author.
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Yan R, Xu Z, Qian J, Zhou Q, Wu H, Liu Y, Guo Y, Zhu G, Chen M. Molecular and functional characterization of a conserved odorant receptor from Aedes albopictus. Parasit Vectors 2022; 15:43. [PMID: 35101118 PMCID: PMC8805257 DOI: 10.1186/s13071-022-05158-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/08/2022] [Indexed: 11/21/2022] Open
Abstract
Background The Asian tiger mosquito Aedes albopictus is a competent vector of several viral arboviruses including yellow fever, dengue fever, and chikungunya. Several vital mosquito behaviors (e.g., feeding, host-seeking, mating, and oviposition) are primarily dependent on the olfactory system for semiochemicals detection and discrimination. However, the limited number of studies hampers our understanding of the relationships between the Ae. albopictus olfactory system and the complex chemical world. Methods We performed RT-qPCR assay on antennae of Ae. albopictus mosquitoes of different sexes, ages and physiological states, and found odorant receptor 11 (AalbOr11) enriched in non-blood-fed female mosquitoes. Then, we examined the odorant preference with a panel of physiologically and behaviorally relevant odorants in Xenopus oocytes. Results The results indicated that AalbOr11 could be activated by ten aromatics, seven terpenes, six heterocyclics, and three alcohols. Furthermore, using post-RNA interference (RNAi) hand-in-cage assay, we found that reducing the transcript level of AalbOr11 affected the repellency activity mediated by (+)-fenchone at a lower concentration (0.01% v/v). Conclusions Using in vitro functional characterization, we found that AalbOr11 was a broadly tuned receptor. Moreover, we found that AalbOr11 shared a conserved odorant reception profile with homologous Anopheles gambiae Or11. In addition, RNAi and bioassay suggested that AablOr11 might be one of the receptors mediating (+)-fenchone repellency activity. Our study attempted to link odor-induced behaviors to odorant reception and may lay the foundation for identifying active semiochemicals for monitoring or controlling mosquito populations. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05158-1.
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15
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Latorre-Estivalis JM, Große-Wilde E, da Rocha Fernandes G, Hansson BS, Lorenzo MG. Changes in antennal gene expression underlying sensory system maturation in Rhodnius prolixus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 140:103704. [PMID: 34942331 DOI: 10.1016/j.ibmb.2021.103704] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Triatomine bugs are the blood feeding insect vectors transmitting Chagas disease to humans, a neglected tropical disease that affects over 8 million people, mainly in Latin America. The behavioral responses to host cues and bug signals in Rhodnius prolixus are state dependent, i.e., they vary as a function of post-ecdysis age. At the molecular level, these changes in behavior are probably due to a modulation of peripheral and central processes. In the present study, we report a significant modulation of the expression of a large set of sensory-related genes. Results were generated by means of antennal transcriptomes of 5th instar larvae along the first week (days 0, 2, 4, 6 and 8) after ecdysis sequenced using the Illumina HiSeq platform. Significant age-induced changes in transcript abundance were established for more than 6120 genes (54,7% of 11,186 genes expressed) in the antenna of R. prolixus. This was especially true between the first two days after ecdysis when more than 2500 genes had their expression significantly altered. In contrast, expression profiles were almost identical between day 6 and 8, with only a few genes showing significant modulation of their expression. A total of 86 sensory receptors, odorant carriers and odorant degrading enzymes were significantly modulated across age points and clustered into three distinct expression profiles. The set of sensory genes whose expression increased with age (profile 3) may include candidates underlying the increased responsiveness to host cues shown by R. prolixus during the first days after molting. For the first time, we describe the maturation process undergone at the molecular level by the peripheral sensory system of a hemimetabolous insect.
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Affiliation(s)
- Jose Manuel Latorre-Estivalis
- Laboratorio de Insectos Sociales, Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires - CONICET, Buenos Aires, Argentina.
| | - Ewald Große-Wilde
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany; Present address: Faculty of Forestry & Wood Science, Excellent Team for Mitigation, Czech University of Life Science, Prague, Czech Republic.
| | | | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany.
| | - Marcelo Gustavo Lorenzo
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou - FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil.
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16
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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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17
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Thongsripong P, Hyman JM, Kapan DD, Bennett SN. Human-Mosquito Contact: A Missing Link in Our Understanding of Mosquito-Borne Disease Transmission Dynamics. ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA 2021; 114:397-414. [PMID: 34249219 PMCID: PMC8266639 DOI: 10.1093/aesa/saab011] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Indexed: 05/26/2023]
Abstract
Despite the critical role that contact between hosts and vectors, through vector bites, plays in driving vector-borne disease (VBD) transmission, transmission risk is primarily studied through the lens of vector density and overlooks host-vector contact dynamics. This review article synthesizes current knowledge of host-vector contact with an emphasis on mosquito bites. It provides a framework including biological and mathematical definitions of host-mosquito contact rate, blood-feeding rate, and per capita biting rates. We describe how contact rates vary and how this variation is influenced by mosquito and vertebrate factors. Our framework challenges a classic assumption that mosquitoes bite at a fixed rate determined by the duration of their gonotrophic cycle. We explore alternative ecological assumptions based on the functional response, blood index, forage ratio, and ideal free distribution within a mechanistic host-vector contact model. We highlight that host-vector contact is a critical parameter that integrates many factors driving disease transmission. A renewed focus on contact dynamics between hosts and vectors will contribute new insights into the mechanisms behind VBD spread and emergence that are sorely lacking. Given the framework for including contact rates as an explicit component of mathematical models of VBD, as well as different methods to study contact rates empirically to move the field forward, researchers should explicitly test contact rate models with empirical studies. Such integrative studies promise to enhance understanding of extrinsic and intrinsic factors affecting host-vector contact rates and thus are critical to understand both the mechanisms driving VBD emergence and guiding their prevention and control.
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Affiliation(s)
- Panpim Thongsripong
- Department of Microbiology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA
| | - James M Hyman
- Department of Mathematics, Tulane University, 6823 St. Charles Avenue, New Orleans, LA 70118, USA
| | - Durrell D Kapan
- Department of Entomology and Center for Comparative Genomics, Institute of Biodiversity Sciences and Sustainability, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA
- Center for Conservation and Research Training, Pacific Biosciences Research Center, University of Hawai’i at Manoa, 3050 Maile Way, Honolulu, HI 96822
| | - Shannon N Bennett
- Department of Microbiology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA
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18
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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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19
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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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20
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Use of odor by host-finding insects: the role of real-time odor environment and odor mixing degree. CHEMOECOLOGY 2021. [DOI: 10.1007/s00049-021-00342-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Hill SR, Taparia T, Ignell R. Regulation of the antennal transcriptome of the dengue vector, Aedes aegypti, during the first gonotrophic cycle. BMC Genomics 2021; 22:71. [PMID: 33478394 PMCID: PMC7821643 DOI: 10.1186/s12864-020-07336-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 12/22/2020] [Indexed: 12/31/2022] Open
Abstract
Background In the light of dengue being the fastest growing transmissible disease, there is a dire need to identify the mechanisms regulating the behaviour of the main vector Aedes aegypti. Disease transmission requires the female mosquito to acquire the pathogen from a blood meal during one gonotrophic cycle, and to pass it on in the next, and the capacity of the vector to maintain the disease relies on a sustained mosquito population. Results Using a comprehensive transcriptomic approach, we provide insight into the regulation of the odour-mediated host- and oviposition-seeking behaviours throughout the first gonotrophic cycle. We provide clear evidence that the age and state of the female affects antennal transcription differentially. Notably, the temporal- and state-dependent patterns of differential transcript abundance of chemosensory and neuromodulatory genes extends across families, and appears to be linked to concerted differential modulation by subsets of transcription factors. Conclusions By identifying these regulatory pathways, we provide a substrate for future studies targeting subsets of genes across disparate families involved in generating key vector behaviours, with the goal to develop novel vector control tools. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-020-07336-w.
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Affiliation(s)
- Sharon Rose Hill
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, 230 54, Alnarp, Sweden.
| | - Tanvi Taparia
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, 230 54, Alnarp, Sweden.,Business Unit Biointeractions and Plant Health, Wageningen University and Research, AA, 6700, Wageningen, The Netherlands
| | - Rickard Ignell
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, 230 54, Alnarp, Sweden
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22
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Abstract
Mosquitoes are emerging as model systems with which to study innate behaviours through neuroethology and functional genomics. Decades of work on these disease vectors have provided a solid behavioural framework describing the distinct repertoire of predominantly odour-mediated behaviours of female mosquitoes, and their dependence on life stage (intrinsic factors) and environmental cues (extrinsic factors). The purpose of this review is to provide an overview of how intrinsic factors, including adult maturation, age, nutritional status, and infection, affect the attraction to plants and feeding on plant fluids, host seeking, blood feeding, supplemental feeding behaviours, pre-oviposition behaviour, and oviposition in female mosquitoes. With the technological advancements in the recent two decades, we have gained a better understanding of which volatile organic compounds are used by mosquitoes to recognise and discriminate among various fitness-enhancing resources, and characterised their neural and molecular correlates. In this review, we present the state of the art of the peripheral olfactory system as described by the neural physiology, functional genomics, and genetics underlying the demonstrated changes in the behavioural repertoire in female mosquitoes. The review is meant as a summary introduction to the current conceptual thinking in the field.
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Affiliation(s)
- Sharon R Hill
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Växtskyddsvägen 3, 23053, Alnarp, Sweden
| | - Rickard Ignell
- Disease Vector Group, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Växtskyddsvägen 3, 23053, Alnarp, Sweden.
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23
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Debebe Y, Hill SR, Tekie H, Dugassa S, Hopkins RJ, Ignell R. Malaria hotspots explained from the perspective of ecological theory underlying insect foraging. Sci Rep 2020; 10:21449. [PMID: 33293574 PMCID: PMC7722757 DOI: 10.1038/s41598-020-78021-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 11/19/2020] [Indexed: 01/16/2023] Open
Abstract
Hotspots constitute the major reservoir for residual malaria transmission, with higher malaria incidence than neighbouring areas, and therefore, have the potential to form the cornerstone for successful intervention strategies. Detection of malaria hotspots is hampered by their heterogenous spatial distribution, and the laborious nature and low sensitivity of the current methods used to assess transmission intensity. We adopt ecological theory underlying foraging in herbivorous insects to vector mosquito host seeking and modelling of fine-scale landscape features at the village level. The overall effect of environmental variables on the density of indoor mosquitoes, sporozoite infected mosquitoes, and malaria incidence, was determined using generalized linear models. Spatial analyses were used to identify hotspots for malaria incidence, as well as malaria vector density and associated sporozoite prevalence. We identify household occupancy and location as the main predictors of vector density, entomological inoculation rate and malaria incidence. We propose that the use of conventional vector control and malaria interventions, integrated with their intensified application targeting predicted hotspots, can be used to reduce malaria incidence in endemic and residual malaria settings.
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Affiliation(s)
- Yared Debebe
- Department of Zoological Sciences, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | - Sharon Rose Hill
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Habte Tekie
- Department of Zoological Sciences, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | - Sisay Dugassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | | | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
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Dengue infection modulates locomotion and host seeking in Aedes aegypti. PLoS Negl Trop Dis 2020; 14:e0008531. [PMID: 32911504 PMCID: PMC7482838 DOI: 10.1371/journal.pntd.0008531] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/27/2020] [Indexed: 12/31/2022] Open
Abstract
Pathogens may manipulate their human and mosquito hosts to enhance disease transmission. Dengue, caused by four viral serotypes, is the fastest-growing transmissible disease globally resulting in 50-100 million infections annually. Transmission of the disease relies on the interaction between humans and the vector Aedes aegypti and is largely dependent on the odor-mediated host seeking of female mosquitoes. In this study, we use activity monitors to demonstrate that dengue virus-1 affects the locomotion and odor-mediated behavior of Ae. aegypti, reflecting the progression of infection within the mosquito. Mosquitoes 4-6 days post-infection increase locomotion, but do not alter their odor-driven host-seeking response. In contrast, females 14-16 days post-infection are less active, yet more sensitive to human odors as assessed by behavioral and electrophysiological assays. Such an increase in physiological and behavioral sensitivity is reflected by the antennal-specific increase in abundance of neural signaling transcripts in 14 days post-infection females, as determined by transcriptome analysis. This suggests that the sensitivity of the mosquito peripheral olfactory system is altered by the dengue virus by enhancing the overall neural responsiveness of the antenna, rather than the selective regulation of chemosensory-related genes. Our study reveals that dengue virus-1 enhances vector-related behaviors in the early stages post-infection that aid in avoiding predation and increasing spatial exploration. On the other hand, at the later stages of infection, the virus enhances the host-seeking capacity of the vector, thereby increasing the risk of virus transmission. A potential mechanism is discussed.
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25
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Debebe Y, Hill SR, Birgersson G, Tekie H, Ignell R. Plasmodium falciparum gametocyte-induced volatiles enhance attraction of Anopheles mosquitoes in the field. Malar J 2020; 19:327. [PMID: 32887614 PMCID: PMC7487932 DOI: 10.1186/s12936-020-03378-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/18/2020] [Indexed: 11/29/2022] Open
Abstract
Background Plasmodium parasites manipulate the interaction between their mosquito and human hosts. Patients infected with gametocytes attract anopheline mosquitoes differentially compared to healthy individuals, an effect associated with an increased release of attractive volatile cues. This odour-driven manipulation is partly mediated by the gametocyte-specific metabolite, (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), which induces increased release of select aldehydes and terpenes from red blood cells and results in the enhanced attraction of host-seeking mosquitoes, which are vectors of malaria. This study investigates the effect of the HMBPP-induced volatiles on the attraction of wild Anopheles mosquitoes to humans under field conditions. Methods The efficacy of the HMBPP-induced odour blend to attract Anopheles was evaluated in a 4 × 6 Latin rectangular study design indoors using baited Suna traps. Furthermore, to assess the efficacy of the HMBPP-induced odour blend in (1) augmenting the attractiveness of human odour, and (2) attracting Anopheles mosquitoes in the absence of human odour, a two-choice assay using host decoy traps (HDTs) was used and evaluated using binomial generalized regression. Results Traps baited with the HMBPP-induced odour blend attracted and caught both Anopheles arabiensis and Anopheles pharoensis females in a dose-dependent manner in the presence of background human odour, up to 2.5 times that of an unbaited trap. Given a choice between human odour and human odour laden with the HMBPP-induced odour blend, mosquitoes differentially preferred traps augmented with the HMBPP-induced odour blend, which caught twice as many female An. arabiensis. Traps baited with the HMBPP-induced odour blend but lacking the background of human odour were not effective in attracting and catching mosquitoes. Conclusion The findings of the present study revealed that the HMBPP-induced odour blend, when augmented with human body odour, is attractive to anopheline mosquitoes and could be used as a complementary vector control tool along with existing strategies.
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Affiliation(s)
- Yared Debebe
- Department of Zoological Sciences, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | - Sharon Rose Hill
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO. Box 102, Alnarp, Sweden
| | - Göran Birgersson
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO. Box 102, Alnarp, Sweden
| | - Habte Tekie
- Department of Zoological Sciences, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia
| | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO. Box 102, Alnarp, Sweden.
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26
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Wynne NE, Lorenzo MG, Vinauger C. Mechanism and plasticity of vectors' host-seeking behavior. CURRENT OPINION IN INSECT SCIENCE 2020; 40:1-5. [PMID: 32199240 DOI: 10.1016/j.cois.2020.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
The host-seeking behavior of disease vector insects is central to the transmission of pathogens. In this context, an improved understanding of the mechanisms that allow vectors to detect, identify and locate a potential host will be crucial to refine existing control strategies and invent new ones. Host-seeking is mediated by the integration of cues that are processed by multiple sensory modalities, and provide robust information about host location and quality. Responses to these cues are plastic and vary as a function of the vector's internal state, age, and previous experience. Vectors also integrate other factors such as time of day, or even the level of defensiveness of the host. Here, we review the most recent advances on the molecular basis of host-seeking behavior, with a particular emphasis on disease vector mosquitoes.
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Affiliation(s)
- Nicole E Wynne
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Marcelo G Lorenzo
- Instituto René Rachou/FIOCRUZ, Av. Augusto de Lima, 1715, Barro Preto, CEP: 30 190 009, Belo Horizonte, Minas Gerais, Brazil
| | - Clément Vinauger
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
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Ignell R, Hill SR. Malaria mosquito chemical ecology. CURRENT OPINION IN INSECT SCIENCE 2020; 40:6-10. [PMID: 32422588 DOI: 10.1016/j.cois.2020.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/25/2020] [Accepted: 03/27/2020] [Indexed: 05/10/2023]
Abstract
The field of mosquito chemical ecology has shifted focus over the past five years, driven by the recognition that odour-mediated behaviours are regulated by distinct chemical codes, that is, odour blends emanating from the natural environment. As a research community, we have shifted from our anthropocentric focus to include other behaviours, including plant seeking and oviposition site seeking, in order to develop new tools to combat residual malaria in the wake of the increased insecticide and behavioural resistance in mosquitoes across sub-Saharan Africa. In this short review, we will outline the progress made, and the future directions, in understanding blend recognition and chemical parsimony, and their implications for preadaptation of the odour coding system in malaria mosquitoes.
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Affiliation(s)
- Rickard Ignell
- Disease Vector Group, Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, 230 53 Alnarp, Sweden
| | - Sharon Rose Hill
- Disease Vector Group, Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, 230 53 Alnarp, Sweden.
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Mbaluto CM, Ayelo PM, Duffy AG, Erdei AL, Tallon AK, Xia S, Caballero-Vidal G, Spitaler U, Szelényi MO, Duarte GA, Walker WB, Becher PG. Insect chemical ecology: chemically mediated interactions and novel applications in agriculture. ARTHROPOD-PLANT INTERACTIONS 2020; 14:671-684. [PMID: 33193908 PMCID: PMC7650581 DOI: 10.1007/s11829-020-09791-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/16/2020] [Indexed: 05/19/2023]
Abstract
Insect chemical ecology (ICE) evolved as a discipline concerned with plant-insect interactions, and also with a strong focus on intraspecific pheromone-mediated communication. Progress in this field has rendered a more complete picture of how insects exploit chemical information in their surroundings in order to survive and navigate their world successfully. Simultaneously, this progress has prompted new research questions about the evolution of insect chemosensation and related ecological adaptations, molecular mechanisms that mediate commonly observed behaviors, and the consequences of chemically mediated interactions in different ecosystems. Themed meetings, workshops, and summer schools are ideal platforms for discussing scientific advancements as well as identifying gaps and challenges within the discipline. From the 11th to the 22nd of June 2018, the 11th annual PhD course in ICE was held at the Swedish University of Agricultural Sciences (SLU) Alnarp, Sweden. The course was made up of 35 student participants from 22 nationalities (Fig. 1a) as well as 32 lecturers. Lectures and laboratory demonstrations were supported by literature seminars, and four broad research areas were covered: (1) multitrophic interactions and plant defenses, (2) chemical communication focusing on odor sensing, processing, and behavior, (3) disease vectors, and (4) applied aspects of basic ICE research in agriculture. This particular article contains a summary and brief synthesis of these main emergent themes and discussions from the ICE 2018 course. In addition, we also provide suggestions on teaching the next generation of ICE scientists, especially during unprecedented global situations.
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Affiliation(s)
- Crispus M. Mbaluto
- Molecular Interaction Ecology, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Pusch straße 4, 04103 Leipzig, Germany
- Institute of Biodiversity, Friedrich-Schiller-Universität Jena, Dornburger Str. 159, 07743 Jena, Germany
| | - Pascal M. Ayelo
- International Centre of Insect Physiology and Ecology (Icipe), P.O. Box 30772-00100, Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Hatfield, Private Bag X20, Pretoria, 0028 South Africa
| | - Alexandra G. Duffy
- Evolutionary Ecology Laboratories, Department of Biology, Brigham Young University, 4102 Life Science Building, Provo, UT 84602 USA
| | - Anna L. Erdei
- Zoology Department, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó str. 15, Budapest, 1022 Hungary
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 102, 23053 Alnarp, Sweden
| | - Anaїs K. Tallon
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 102, 23053 Alnarp, Sweden
| | - Siyang Xia
- Department of Ecology and Evolutionary Biology, Yale University, 21 Sachem Street, New Haven, CT 06511 USA
| | - Gabriela Caballero-Vidal
- INRAE, Institute of Ecology and Environmental Sciences of Paris, CNRS, IRD, UPEC, Sorbonne Université, Université Paris Diderot, Route de Saint-Cyr, 78026 Versailles Cedex, France
| | - Urban Spitaler
- Institute of Plant Health, Laimburg Research Centre, Laimburg 6, 3904 Ora, South Tyrol Italy
- Department of Crop Sciences, Institute of Plant Protection, University of Natural Resources and Life Sciences (BOKU), Gregor-Mendel-Straße 33, 1180 Vienna, Austria
| | - Magdolna O. Szelényi
- Zoology Department, Plant Protection Institute, Centre for Agricultural Research, Herman Ottó str. 15, Budapest, 1022 Hungary
| | - Gonçalo A. Duarte
- LEAF-Linking Landscape, Environment, Agriculture and Food Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal
| | - William B. Walker
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 102, 23053 Alnarp, Sweden
| | - Paul G. Becher
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, P.O. Box 102, 23053 Alnarp, Sweden
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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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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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