A potential link between aromatics-induced oviposition repellency behaviors and specific odorant receptor of Aedes albopictus.

BACKGROUND: The Asian tiger mosquito, Aedes albopictus, is a competent vector for the spread of several viral arboviruses including dengue, chikungunya, and Zika. Several vital mosquito behaviors linked to survival and reproduction are primarily dependent on sophisticated olfactory system for semiochemical perception. However, limited studies hampered our understanding of the relationship between the A. albopictus acute olfactory system and complex chemical world.

RESULTS: Here we performed qRT-PCR assay on A. albopictus antenna in different sex, age, and physiological state, and found AalbOr10 enriched in blood-fed female mosquitoes. Then, we used single sensillum recording to deorphan AalbOr10 with a panel of physiologically and behaviorally relevant odorants in Drosophila 'empty neuron' system. The results indicated that AalbOr10 was activated by 7 aromatic compounds, and all of these compounds hampered blood-fed mosquitoes laying eggs. Furthermore, through post-RNAi oviposition assay, we found reducing transcript level of AalbOr10 affected the repellent activity mediated by 2-ethylphenol at low concentration (10-4 vol/vol). Computational modeling and molecular docking studies suggested that hydrogen bonds to Y68 and Y150 mediated the interaction of 2-ethylphenol with AalbOr10.

CONCLUSION: We revealed a potential link between aromatics-induced oviposition repellency behaviors and specific odorant receptor of A. albopictus. Our findings might lay the foundation for identifying active semiochemicals for monitoring or controlling mosquito populations. This article is protected by copyright. All rights reserved.