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Applebach, E.

Publications and source records attributed to Applebach, E..

2 recordsLinked to original sources

Temporal synchrony between human odor rhythms and mosquito olfactory preference shapes host attraction

For anthropophilic mosquitoes such as Aedes aegypti, aligning host-seeking with human availability enhances foraging efficiency and reproductive success. Although time of day modulates mosquito activity and olfactory sensitivity, it remains unknown whether human hosts display rhythmic changes in odor cues and whether mosquitoes adjust their sensory responses accordingly. Here, we combine chemical, behavioral, genetic, and transcriptomic approaches to reveal that both mosquitoes and their human hosts in this interaction are temporally synchronized. Gas chromatography-mass spectrometry showed systematic daily shifts in human body odor composition between morning and evening. Correspondingly, mosquitoes prefer host odors that match their own active phase--a time-specific preference abolished in timeless mutants and under constant darkness. Silencing the timeless gene further induced an aversion for the host scent under light-dark conditions. Transcriptomic analysis of mosquito heads and antennae uncovered rhythmic expression of sensory and neuromodulatory genes, driven by both circadian and light-dark cycles and which peaks during mosquitoes active periods, with rhythmic co-expression networks collapsing in timeless knockouts. Together, these results show that mosquito attraction to humans is temporally tuned by the interplay of host odor rhythms and mosquito sensory rhythms, revealing a previously unrecognized form of interspecific temporal synchronization in vector-host interactions.

animal behavior and cognition↗

Aedes albopictus colonies from different geographic origins differ in their sleep and activity levels but not in the time of peak activity

Mosquitoes occupy a wide range of habitats where they experience various environmental conditions. The ability of some species, such as the tiger mosquito, Aedes albopictus, to adapt to local conditions certainly contributes to their invasive success. Among traits that remain to be examined, mosquitoes ability to time their activity with that of the local host population has been suggested to be of significant epidemiological importance. However, whether different populations display heritable differences in their chronotype has not been examined. Here, we compared laboratory strains originating from 8 populations from 3 continents, monitored their spontaneous locomotor activity patterns, and analyzed their sleep-like states. Overall, all strains showed conserved diurnal activity concentrated in the hours preceding the crepuscule. Similarly, they all showed increased sleep levels during the morning and night hours. However, we observed strain-specific differences in the activity levels at each phase of the day. We also observed differences in the fraction of time that each strain spends in a sleep-like state, explained by variations in the sleep architecture across strains. Human population density and the latitude of the site of geographic origin of the tested strain showed significant effects on sleep and activity patterns. Altogether, these results suggest that Ae. albopictus mosquitoes adapt to local environmental conditions via heritable adaptations of their chronotype.

animal behavior and cognition↗