Behavioral and postural analyses establish sleep-like states for mosquitoes that can impact host landing and blood feeding

Abstract

Sleep is an evolutionarily conserved process that has been described in different animal systems. For insects, sleep characterization has been primarily achieved using behavioral and electrophysiological correlates in a few systems. Sleep in mosquitoes, which are important vectors of disease-causing pathogens, has not been directly examined. This is surprising as circadian rhythms, which have been well studied in mosquitoes, influence sleep in other systems. In this study, we characterized sleep in mosquitoes using body posture analysis and behavioral correlates, and quantified the effect of sleep deprivation on sleep rebound and host landing. Body and appendage position metrics revealed a clear distinction between the posture of mosquitoes in their putative sleep and awake states for multiple species, which correlates with a reduction in responsiveness to host cues. Sleep assessment informed by these posture analyses indicated significantly more sleep during periods of low activity. Nighttime and daytime sleep deprivation resulting from the delivery of vibration stimuli induced sleep rebound in the subsequent phase in day and night active mosquitoes, respectively. Lastly, sleep deprivation suppressed host landing in both laboratory and field settings when mosquitoes would normally be active. These results suggest that quantifiable sleep states occur in mosquitoes, and highlight the potential epidemiological importance of mosquito sleep.

Tyrosine transfer RNA levels and modifications during blood-feeding and vitellogenesis in the mosquito,Aedes aegypti

“…A human volunteer provided a blood meal to female mosquitoes for 30 minutes and mosquitoes were visually inspected to confirm blood ingestion. Human feeding studies were approved by the University of Cincinnati Institutional Review Board, IRB - 2021-0971 (Ajayi et al, 2021). After blood-feeding, 60-70 mosquitoes were collected at each time point (6H, 12H, 24H, 48H, 72H) and immediately frozen at -80 °C until RNA isolation.…”

“…Human feeding studies were approved by the University of Cincinnati Institutional Review Board, IRB -2021-0971 (Ajayi et al, 2021). After blood-feeding, 60-70 mosquitoes were collected at each time point (6H, 12H, 24H, 48H, 72H) and immediately frozen at -80 o C until RNA isolation.…”