Abstract
Some organisms can adapt to seasonal and other environmental challenges by entering a state of dormancy, diapause. Thus, insects exposed to decreased temperature and short photoperiod enter a state of arrested development, lowered metabolism, and increased stress resistance. Drosophila melanogaster females can enter a shallow reproductive diapause in the adult stage, which drastically reduces organismal senescence, but little is known about the physiology and endocrinology associated with this dormancy, and the genes involved in its regulation. We induced diapause in D. melanogaster and monitored effects over 12 weeks on dynamics of ovary development, carbohydrate and lipid metabolism, as well as expression of genes involved in endocrine signaling, metabolism and innate immunity. During diapause food intake diminishes drastically, but circulating and stored carbohydrates and lipids are elevated. Gene transcripts of glucagon- and insulin-like peptides increase, and expression of several target genes of these peptides also change. Four key genes in innate immunity can be induced by infection in diapausing flies, and two of these, drosomycin and cecropin A1, are upregulated by diapause independently of infection. Diapausing flies display very low mortality, extended lifespan and decreased aging of the intestinal epithelium. Many phenotypes induced by diapause are reversed after one week of recovery from diapause conditions. Furthermore, mutant flies lacking specific insulin-like peptides (dilp5 and dilp2-3) display increased diapause incidence. Our study provides a first comprehensive characterization of reproductive diapause in D. melanogaster, and evidence that glucagon- and insulin-like signaling are among the key regulators of the altered physiology during this dormancy.
Highlights
A capacity for adaptive changes in response to environmental challenges is critical for animal survival
Induction of reproductive diapause by short day length and low temperature: phenotyping by ovarian development some authors consider that only low temperature, and not day length, is critical for induction of adult reproductive diapause in D. melanogaster, we decided to follow the protocol of Saunders for the Canton S strain [13,41] and Tatar for the Windsor strain [14] and expose virgin female flies to a combination of 11uC and short photoperiod (10L:14D)
These one week-old nondiapausing flies should correspond phenotypically to flies used as controls in studies of insulin signaling and metabolism in Drosophila
Summary
A capacity for adaptive changes in response to environmental challenges is critical for animal survival. When exposed to harsh conditions animals, such as for instance insects and nematode worms, enter a reversible state of developmental arrest and metabolic restructuring, coupled with increased stress resistance and extended lifespan [1,2,3,4,5,6,7]. In many insects this temporary suppression of development and reallocation of energy resources is pre-programmed and obligate known as diapause or dormancy [4,5]. The dormancy in D. melanogaster has been referred to as diapause by most authors
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
