We are excited to share two new preprints!
The first one is a collaborative project with Claudio Lazzari, Aurélie Fauqet, Ricardo Araujo and Marcos Pereira: "Soft ticks perform evaporative cooling during blood-feeding".
Abstract: Feeding on the blood of warm-blooded vertebrates is associated to thermal stress in haematophagous arthropods. It has been demonstrated that blood-sucking insects protect their physiological integrity either by synthesising heat-shock proteins or by means of thermoregulatory mechanisms. In this work, we describe the first thermoregulatory mechanism in a tick species, Ornithodoros rostratus. By performing real-time infrared thermography during feeding on mice we found that this acarian eliminates big amounts of fluid (urine) through their coxal glands; this fluid quickly spreads over the cuticular surface and its evaporation cools-down the body of the tick. The spread of the fluid is possible thanks to capillary diffusion through the sculptured exoskeleton of Ornithodoros. We discuss our findings in the frame of the adaptive strategies to cope with the thermal stress experienced by blood-sucking arthropods at each feeding event warm-blooded hosts.
Available here: https://www.biorxiv.org/content/10.1101/2020.06.30.180968v1
The second one is a "pandemic time" paper lead by Joanna Reinhold and Ryan Shaw: "Beat the heat: Culex quinquefasciatus regulates its body temperature during blood-feeding".
Abstract: Mosquitoes are regarded as one of the most dangerous animals on earth. As they are responsible for the spread of a wide range of both human and animal diseases, research of the underlying mechanisms of their feeding behavior and physiology is critical. Among disease vector mosquitoes, Culex quinquefasciatus, which is a known carrier of West Nile virus and Western Equine Encephalitis, remains relatively understudied. As blood sucking insects, adaptations (either at the molecular or physiological level) while feeding on warm blood is crucial to their survival, as overheating can result in death due to heat stress. Our research aims to study how Cx. quinquefasciatus copes with heat associated with the ingestion of a warm blood-meal and to possibly uncover the adaptations this species uses to avoid thermal stress. Through the use of thermographic imaging, we analyzed the body temperature of Cx. quinquefasciatus while blood feeding. Infrared thermography has allowed us to identify a cooling strategy, evaporative cooling via the production of fluid droplets, and an overall low body temperature in comparison to the blood temperature during feeding. Understanding Cx. quinquefasciatus’ adaptations and various strategies that they employ to reduce their body temperature while blood-feeding constitutes the first step towards the discovery of potential targets of opportunity for their control.
Available here: https://www.biorxiv.org/content/10.1101/2020.07.07.190157v1.full