71 Oral - Immunity and Microbiome
Friday April 08, 9:45 AM - 10:00 AM

Authors:
Samuel Rommelaere ¹; Alexia L. Carboni ¹; Jean-Philippe Boquete ¹; Shu Kondo ²; Bruno Lemaitre ¹

Affiliations:
1) Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; 2) Invertebrate Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, Mishima, Japan

Keywords:
f. JAK-STAT signaling; a. stress responses

Turandot (Tot) genes code for a family of height small secreted proteins. They are highly expressed in response to a variety of stresses. Tots are transcriptional targets of several stress pathways, including the JAK/STAT and p38 MAPK pathways. Although Tots have been extensively used as readouts of the stress response, they have never been functionally characterized. We have generated a Drosophila line that lacks 6 Tots (Tot^XMAZ). These mutant flies are extremely susceptible to several challenges, including bacterial infection, starvation and osmotic stress. Phenotypically, Tot^XMAZ flies have reduced triglyceride content. During stress exposure, their lipid and carbohydrate stores are rapidly depleted, suggesting that energy availability is a limiting factor in the stress response of these flies. Indeed, feeding Tot^XMAZ flies a high-sugar diet improves their survival to osmotic stress. Tots may thus participate in the stress response by tempering energy utilization. Turandot proteins secreted by the fat body specifically bind to tracheas. Interestingly, tissue tracheation is reduced in Tot^XMAZ mutant and restoring tracheal growth in these flies is sufficient to rescue their susceptibility to stress. Altogether, our data suggest that Turandot proteins participate in the adaptation to stress by controlling tracheal growth and nutrient utilization. We propose that Turandot may adjust the fly metabolic rate by controlling tracheal homeostasis under stress conditions.