A Drosophila insulin-like peptide promotes growth during nonfeeding states.
In metazoans, tissue growth relies on the availability of nutrients--stored internally or obtained from the environment--and the resulting activation of insulin/IGF signaling (IIS). In Drosophila, growth is mediated by seven Drosophila insulin-like peptides (Dilps), acting through a canonical IIS pathway. During the larval period, animals feed and Dilps produced by the brain couple nutrient uptake with systemic growth. We show here that, during metamorphosis, when feeding stops, a specific DILP (Dilp6) is produced by the fat body and relays the growth signal. Expression of DILP6 during pupal development is controlled by the steroid hormone ecdysone. Remarkably, DILP6 expression is also induced upon starvation, and both its developmental and environmental expression require the Drosophila FoxO transcription factor. This study reveals a specific class of ILPs induced upon metabolic stress that promotes growth in conditions of nutritional deprivation or following developmentally induced cessation of feeding.
Slaidina
Maija
M
Institute for Developmental Biology and Cancer, University of Nice-Sophia Antipolis/Centre National de la Recherche Scientifique, Parc Valrose, 06108 Nice, France.
Delanoue
Rénald
R
Gronke
Sebastian
S
Partridge
Linda
L
Léopold
Pierre
P
D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000254:growth & development* / Q000378:metabolism*; D004440:Ecdysone / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015398:Signal Transduction; D013002:Somatomedins / Q000235:genetics / Q000378:metabolism*; D013217:Starvation / Q000378:metabolism
D029721:Drosophila Proteins; C477334:FOXO protein, Drosophila; D051858:Forkhead Transcription Factors; C546576:Ilp6 protein, Drosophila; D013002:Somatomedins; D004440:Ecdysone