The temporal requirements for insulin signaling during development in Drosophila
| Autor: | Lucio Vinicius, Jayatri Das, Alexander W. Shingleton, David L. Stern |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: |
medicine.medical_specialty
Time Factors Insulin Receptor Substrate Proteins Evolution Physiology QH301-705.5 medicine.medical_treatment Development General Biochemistry Genetics and Molecular Biology Internal medicine medicine Animals Drosophila Proteins Insulin Biology (General) Nutrition General Immunology and Microbiology biology General Neuroscience fungi Intracellular Signaling Peptides and Proteins Receptor Protein-Tyrosine Kinases Organ Size biology.organism_classification Insulin receptor Endocrinology Insect Hormones Larva Mutation biology.protein Drosophila Drosophila melanogaster Signal transduction General Agricultural and Biological Sciences Drosophila Protein Pupariation Signal Transduction Research Article |
| Zdroj: | PLoS Biology, Vol 3, Iss 9, p e289 (2005) PLoS Biology |
| ISSN: | 1545-7885 1544-9173 |
| Popis: | Recent studies have indicated that the insulin-signaling pathway controls body and organ size in Drosophila, and most metazoans, by signaling nutritional conditions to the growing organs. The temporal requirements for insulin signaling during development are, however, unknown. Using a temperature-sensitive insulin receptor (Inr) mutation in Drosophila, we show that the developmental requirements for Inr activity are organ specific and vary in time. Early in development, before larvae reach the “critical size” (the size at which they commit to metamorphosis and can complete development without further feeding), Inr activity influences total development time but not final body and organ size. After critical size, Inr activity no longer affects total development time but does influence final body and organ size. Final body size is affected by Inr activity from critical size until pupariation, whereas final organ size is sensitive to Inr activity from critical size until early pupal development. In addition, different organs show different sensitivities to changes in Inr activity for different periods of development, implicating the insulin pathway in the control of organ allometry. The reduction in Inr activity is accompanied by a two-fold increase in free-sugar levels, similar to the effect of reduced insulin signaling in mammals. Finally, we find that varying the magnitude of Inr activity has different effects on cell size and cell number in the fly wing, providing a potential linkage between the mode of action of insulin signaling and the distinct downstream controls of cell size and number. We present a model that incorporates the effects of the insulin-signaling pathway into the Drosophila life cycle. We hypothesize that the insulin-signaling pathway controls such diverse effects as total developmental time, total body size and organ size through its effects on the rate of cell growth, and proliferation in different organs. Studies using a temperature-sensitive insulin receptor elucidate the temporal requirements for insulin signaling in Drosophila; insulin signaling at different times during development affects many characters, such as total developmental time, total body size and organ size. |
| Databáze: | OpenAIRE |
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