Feeding state modulates body temperatures and the controlling pathway in Drosophila
Mar. 5, 2019 16:00 - 17:00
DB Bldg. SeminarRoom A7F
Cincinnati Children's Hospital Medical Center (Dr. Fumika Hamada Lab)
Animals adjust their behavior or physiological responses according to their internal state. Feeding state is important for setting their physiological conditions. A prolonged starvation is life-threatening, and therefore starvation causes lower metabolism and body temperature for survival. However, how internal nutrient information is decoded in target neurons in the brain, which in turn modulates their body temperature is largely unknown. We previously showed that fruit flies, Drosophila melanogaster, exhibit a robust temperature preference behavior and we show here that starvation causes a lower preferred temperature (Tp). Because flies are small ectotherms, the lower Tp could result in lower metabolism and body temperature. Furthermore, longer starved flies show more colder Tp and the phenotype is restored when the flies refeed a normal food after starvation. We determine that Insulin-like peptide 6 (Ilp6) in the fat body (equivalent to liver and adipose tissues in mammals) and insulin signaling in the transient receptor potential A1 (TrpA1)-expressing cells (Anterior cells; ACs) are responsible for reduction in Tp. Importantly, starvation decreases the responding temperature of ACs depending on insulin signaling, which results in lower Tp. Together, our results suggest that internal nutrient information from fat tissues to brain via insulin signaling regulates the starvation-dependent thermoregulation.