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Rouyar A, Patil AA, Leon-Noreña M, Li M, Coutinho-Abreu IV, Akbari OS, Riffell JA. Transgenic line for characterizing GABA-receptor expression to study the neural basis of olfaction in the yellow-fever mosquito. Front Physiol 2024; 15:1381164. [PMID: 38606012 PMCID: PMC11008680 DOI: 10.3389/fphys.2024.1381164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/14/2024] [Indexed: 04/13/2024] Open
Abstract
The mosquito Aedes aegypti is an important vector of diseases including dengue, Zika, chikungunya, and yellow fever. Olfaction is a critical modality for mosquitoes enabling them to locate hosts, sources of nectar, and sites for oviposition. GABA is an essential neurotransmitter in olfactory processing in the insect brain, including the primary olfactory center, the antennal lobe. Previous work with Ae. aegypti has suggested that antennal lobe inhibition via GABA may be involved in the processing of odors. However, little is known about GABA receptor expression in the mosquito brain, or how they may be involved in odor attraction. In this context, generating mutants that target the mosquito's olfactory responses, and particularly the GABAergic system, is essential to achieve a better understanding of these diverse processes and olfactory coding in these disease vectors. Here we demonstrate the potential of a transgenic line using the QF2 transcription factor, GABA-B1QF2-ECFP, as a new neurogenetic tool to investigate the neural basis of olfaction in Ae. aegypti. Our results show that the gene insertion has a moderate impact on mosquito fitness. Moreover, the line presented here was crossed with a QUAS reporter line expressing the green fluorescent protein and used to determine the location of the metabotropic GABA-B1 receptor expression. We find high receptor expression in the antennal lobes, especially the cell bodies surrounding the antennal lobes. In the mushroom bodies, receptor expression was high in the Kenyon cells, but had low expression in the mushroom body lobes. Behavioral experiments testing the fruit odor attractants showed that the mutants lost their behavioral attraction. Together, these results show that the GABA-B1QF2-ECFP line provides a new tool to characterize GABAergic systems in the mosquito nervous system.
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Affiliation(s)
- Angela Rouyar
- Department of Biology, University of Washington, Seattle, WA, United States
| | - Anandrao A. Patil
- Department of Biology, University of Washington, Seattle, WA, United States
| | | | - Ming Li
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Iliano V. Coutinho-Abreu
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Omar S. Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Jeff A. Riffell
- Department of Biology, University of Washington, Seattle, WA, United States
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Chan JK, Parasurama S, Atlas R, Xu R, Jongebloed UA, Alexander B, Langenhan JM, Thornton JA, Riffell JA. Olfaction in the Anthropocene: NO 3 negatively affects floral scent and nocturnal pollination. Science 2024; 383:607-611. [PMID: 38330103 DOI: 10.1126/science.adi0858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 01/04/2024] [Indexed: 02/10/2024]
Abstract
There is growing concern about sensory pollutants affecting ecological communities. Anthropogenically enhanced oxidants [ozone (O3) and nitrate radicals (NO3)] rapidly degrade floral scents, potentially reducing pollinator attraction to flowers. However, the physiological and behavioral impacts on pollinators and plant fitness are unknown. Using a nocturnal flower-moth system, we found that atmospherically relevant concentrations of NO3 eliminate flower visitation by moths, and the reaction of NO3 with a subset of monoterpenes is what reduces the scent's attractiveness. Global atmospheric models of floral scent oxidation reveal that pollinators in certain urban areas may have a reduced ability to perceive and navigate to flowers. These results illustrate the impact of anthropogenic pollutants on an animal's olfactory ability and indicate that such pollutants may be critical regulators of global pollination.
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Affiliation(s)
- J K Chan
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
| | - S Parasurama
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - R Atlas
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
| | - R Xu
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
- Center for Earth System Science, Tsinghua University, Beijing 100084, China
| | - U A Jongebloed
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
| | - B Alexander
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
| | - J M Langenhan
- Department of Chemistry, Seattle University, Seattle, WA 98122, USA
| | - J A Thornton
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
| | - J A Riffell
- Department of Biology, University of Washington, Seattle, WA 98195, USA
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Vainer Y, Wang Y, Huff RM, Ghaninia M, Coutinho-Abreu IV, Sar-Shalom E, Ruiz C, Perets D, Yakir E, Rajamanickam D, Warburg A, Papathanos P, Akbari OS, Ignell R, Riffell JA, Pitts RJ, Bohbot JD. The evolution of borneol repellency in culicine mosquitoes. bioRxiv 2023:2023.08.01.548337. [PMID: 37577635 PMCID: PMC10418152 DOI: 10.1101/2023.08.01.548337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Insects have developed remarkable adaptations to effectively interact with plant secondary metabolites and utilize them as cues to identify suitable hosts. Consequently, humans have used aromatic plants for centuries to repel mosquitoes. The repellent effects of plant volatile compounds are mediated through olfactory structures present in the antennae, and maxillary palps of mosquitoes. Mosquito maxillary palps contain capitate-peg sensilla, which house three olfactory sensory neurons, of which two are mainly tuned to either carbon dioxide or octenol - two animal host odorants. However, the third neuron, which expresses the OR49 receptor, has remained without a known ecologically-relevant odorant since its initial discovery. In this study, we used odorant mixtures and terpenoid-rich Cannabis essential oils to investigate the activation of OR49. Our results demonstrate that two monoterpenoids, borneol and camphor, selectively activate OR49, and OR9-expressing neurons, as well as the MD3 glomerulus in the antennal lobe. We confirm that borneol repels female mosquitoes, and knocking out the gene encoding the OR49 receptor suppresses the response of the corresponding olfactory sensory neuron. Importantly, this molecular mechanism of action is conserved across culicine mosquito species, underscoring its significance in their olfactory systems.
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Affiliation(s)
- Yuri Vainer
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel
| | - Yinliang Wang
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel
- Northeast Normal University, China
| | - Robert M Huff
- Department of Biology, Baylor University, Waco, Texas, USA
| | - Majid Ghaninia
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Iliano V Coutinho-Abreu
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
| | - Evyatar Sar-Shalom
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel
| | - Carlos Ruiz
- Department of Biology, University of Washington, Seattle, WA, USA 98195
| | - Dor Perets
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel
| | - Esther Yakir
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel
| | | | - Alon Warburg
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Kuvin Centre for the Study of Infectious and Tropical Diseases, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Philippos Papathanos
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel
| | - Omar S Akbari
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, USA
| | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Jeff A Riffell
- Department of Biology, University of Washington, Seattle, WA, USA 98195
| | - R Jason Pitts
- Department of Biology, Baylor University, Waco, Texas, USA
| | - Jonathan D Bohbot
- Department of Entomology, The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel
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Leiser-Miller LB, Kaliszewska ZA, Lauterbur ME, Mann B, Riffell JA, Santana SE. A Fruitful Endeavor: Scent Cues and Echolocation Behavior Used by Carollia castanea to Find Fruit. Integr Org Biol 2020; 2:obaa007. [PMID: 33791551 PMCID: PMC7671165 DOI: 10.1093/iob/obaa007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Frugivores have evolved sensory and behavioral adaptations that allow them to find ripe fruit effectively, but the relative importance of different senses in varying foraging scenarios is still poorly understood. Within Neotropical ecosystems, short-tailed fruit bats (Carollia: Phyllostomidae) are abundant nocturnal frugivores that rely primarily on Piper fruits as a food resource. Previous research has demonstrated that Carollia employs olfaction and echolocation to locate Piper fruit, but it is unknown how their sensory use and foraging decisions are influenced by the complex diversity of chemical cues that fruiting plants produce. Using free-ranging C. castanea and their preferred food, Piper sancti-felicis, we conducted behavioral experiments to test two main hypotheses: (1) foraging decisions in C. castanea are primarily driven by ripe fruit scent and secondarily by vegetation scent, and (2) C. castanea re-weights their sensory inputs to account for available environmental cues, with bats relying more heavily on echolocation in the absence of adequate scent cues. Our results suggest that C. castanea requires olfactory information and relies almost exclusively on ripe fruit scent to make foraging attempts. Piper sancti-felicis ripe fruit scent is chemically distinct from vegetation scent; it is dominated by 2-heptanol, which is absent from vegetation scent, and has a greater abundance of β-caryophyllene, β-ocimene, γ-elemene, and α-cubebene. Although variation in echolocation call parameters was independent of scent cue presence, bats emitted longer and more frequent echolocation calls in trials where fruit scent was absent. Altogether, these results highlight the adaptations and plasticity of the sensory system in neotropical fruit bats.
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Affiliation(s)
- L B Leiser-Miller
- Department of Biology, University of Washington, Seattle, WA 98195, USA.,Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98195, USA
| | - Z A Kaliszewska
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - M E Lauterbur
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
| | - Brianna Mann
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - J A Riffell
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - S E Santana
- Department of Biology, University of Washington, Seattle, WA 98195, USA.,Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98195, USA
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