TRPA1 tunes mosquito thermotaxis to host temperatures

Thermotaxis is a sensory-motor behavior that guides animals toward a preferred temperature. This type of sensory navigation allows animals to avoid environments of noxious cold and heat, with the goal of remaining in physiologically suitable ambient temperatures. For ectotherms such as insects, thermotaxis behavior is the primary method of thermoregulation. Many invertebrates are vulnerable to temperature extremes, facing the risk of desiccation at elevated temperatures, and rapid hypothermia at low temperatures. Therefore, mechanisms to detect environmental temperatures and trigger appropriate approach or avoidance behaviors are extremely important for their survival. For instance, adult C. elegans worms migrate preferentially towards a specific thermal environment determined by the temperature of their cultivation (Hedgecock and Russell, 1975; Mori and Ohshima, 1995). Adult Drosophila melanogaster flies prefer a narrow range of air temperatures around 24-25°C (Sayeed and Benzer, 1996; Hamada et al., 2008) and rapidly avoid air temperatures of ~31°C (Ni et al., 2013).