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- Melo, Nadia, et al.
(författare)
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Geosmin Attracts Aedes aegypti Mosquitoes to Oviposition Sites
- 2020
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822. ; 30:1, s. 5-134
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Tidskriftsartikel (refereegranskat)abstract
- Geosmin is one of the most recognizable and common microbial smells on the planet. Some insects, like mosquitoes, require microbial-rich environments for their progeny, whereas for other insects such microbes may prove dangerous. In the vinegar fly Drosophila melanogaster, geosmin is decoded in a remarkably precise fashion and induces aversion, presumably signaling the presence of harmful microbes [1]. We have here investigated the effect of geosmin on the behavior of the yellow fever mosquito Aedes aegypti. In contrast to flies, geosmin is not aversive but mediates egg-laying site selection. Female mosquitoes likely associate geosmin with microbes, including cyanobacteria consumed by larvae [2], who also find geosmin—as well as geosmin-producing cyanobacteria—attractive. Using in vivo multiphoton calcium imaging from transgenic PUb-GCaMP6s mosquitoes, we show that Ae. aegypti code geosmin in a qualitatively similar fashion to flies, i.e., through a single olfactory channel with a high degree of sensitivity for this volatile. We further demonstrate that geosmin can be used as bait under field conditions, and finally, we show that geosmin, which is both expensive and difficult to obtain, can be substituted by beetroot peel extract, providing a cheap and viable potential mean for mosquito control and surveillance in developing countries.
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| 2. |
- Raj, Joshua I., et al.
(författare)
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Aedes aegypti mosquitoes detect acidic volatiles found in human odor using the IR8a pathway
- 2019
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Ingår i: Current biology : CB. - : Elsevier BV. - 1879-0445 .- 0960-9822. ; 29:8, s. 1253-1262
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Tidskriftsartikel (refereegranskat)abstract
- Mosquitoes use olfaction as a primary means of detecting their hosts. Previously, the functional ablation of a family of Aedes aegypti olfactory receptors, the odorant receptors (ORs), was not sufficient to reduce host seeking in the presence of carbon dioxide (CO2). This suggests the olfactory receptors that remain, such as the ionotropic receptors (IRs), could play a significant role in host detection. To test this, we disrupted the Ir8a co-receptor in Ae. aegypti using CRISPR/Cas9. We found that Ir8a mutant female mosquitoes are not attracted to lactic acid, a behaviorally active component of human sweat, and they lack odor-evoked responses to acidic volatiles. The loss of Ir8a reduces mosquito attraction to humans and their odor. We show that the CO2-detection pathway is necessary but not sufficient for IR8a to detect human odor. Our study reveals that the IR8a pathway is crucial for an anthropophilic vector mosquito to effectively seek hosts.
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