Aging and warmer temperatures interactively weaken intestinal barrier integrity in the mosquito

Like most organisms, mosquitoes experience senescence, an evolutionarily conserved process where body condition and function deteriorate with aging. Degradation of intestinal barrier integrity is a hallmark of senescence, and in mosquitoes this process is important because the intestinal epithelium is the first barrier to infection with blood-borne pathogens. The rate of senescence can be influenced by environmental temperature. Mosquitoes cannot regulate their body temperature, so, for example, their body temperature rises when the environmental temperature rises. Because warmer temperatures alter the mosquito’s metabolism and body condition, we hypothesized that warmer temperatures accelerate the degradation of the intestinal barrier. Therefore, we investigated how aging, warmer temperatures, and their interaction shape the intestinal barrier integrity and function in the African malaria mosquito, Anopheles gambiae. Our preliminary findings suggest that aging and warmer temperature weaken intestinal barrier integrity and reduce excretory function. Specifically, at warmer temperatures, the aging-dependent degradation of intestinal barrier occurs earlier in the mosquito’s life, and the amount of excretion is decreased in mosquitoes at warmer temperatures. However, intestinal pH homeostasis is disrupted with aging but not temperature. Taken together, this study shows that aging and warmer temperature interactively accelerate senescence, deteriorating intestinal barrier integrity.