title: Drosophila insulin-like peptide 1 (DILP1) is transiently expressed during non-feeding stages and reproductive dormancy.
abstract: The insulin/insulin-like growth factor signaling pathway is evolutionarily conserved in animals, and is part of nutrient-sensing mechanisms that control growth, metabolism, reproduction, stress responses, and lifespan. In Drosophila, eight insulin-like peptides (DILP1-8) are known, six of which have been investigated in some detail, whereas expression and functions of DILP1 and DILP4 remain enigmatic. Here we demonstrate that dilp1/DILP1 is transiently expressed in brain insulin producing cells (IPCs) from early pupa until a few days of adult life. However, in adult female flies where diapause is triggered by low temperature and short days, within a time window 0-10h post-eclosion, the dilp1/DILP1 expression remains high for at least 9 weeks. The dilp1 mRNA level is increased in dilp2, 3, 5 and dilp6 mutant flies, indicating feedback regulation. Furthermore, the DILP1 expression in IPCs is regulated by short neuropeptide F, juvenile hormone and presence of larval adipocytes. Male dilp1 mutant flies display increased lifespan and reduced starvation resistance, whereas in female dilp1 mutants oviposition is reduced. Thus, DILP1 is expressed in non-feeding stages and in diapausing flies, is under feedback regulation and appears to play sex-specific functional roles.
authors.affiliation: Department of Zoology, Stockholm University, S-10691 Stockholm, Sweden.
authors.forename: Yiting
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Zoology, Stockholm University, S-10691 Stockholm, Sweden.
authors.forename: Sifang
authors.initials: S
authors.lastname: Liao
authors.affiliation: INCIA UMR 5287 CNRS, Université de Bordeaux, 33405 Talence Cedex, France.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Veenstra
authors.affiliation: Department of Zoology, Stockholm University, S-10691 Stockholm, Sweden.
authors.forename: Dick R
authors.initials: DR
authors.lastname: Nässel
mesh_terms: D000818:Animals; D064666:Diapause, Insect / Q000502:physiology*; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D051034:Inhibitor of Apoptosis Proteins / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D011679:Pupa; D012098:Reproduction / Q000502:physiology
chemical_list: C111892:DIAP2 protein, Drosophila; D029721:Drosophila Proteins; D051034:Inhibitor of Apoptosis Proteins; D009479:Neuropeptides; C400215:neuropeptide F, Drosophila