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Landis GN, Bell HS, Peng OK, Fan Y, Yan K, Baybutt B, Tower J. Conditional Inhibition of Eip75B Eliminates the Effects of Mating and Mifepristone on Lifespan in Female Drosophila. Cells 2024; 13:1123. [PMID: 38994975 PMCID: PMC11240670 DOI: 10.3390/cells13131123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/17/2024] [Accepted: 06/24/2024] [Indexed: 07/13/2024] Open
Abstract
Mating in female Drosophila melanogaster causes midgut hypertrophy and reduced lifespan, and these effects are blocked by the drug mifepristone. Eip75B is a transcription factor previously reported to have pleiotropic effects on Drosophila lifespan. Because Eip75B null mutations are lethal, conditional systems and/or partial knock-down are needed to study Eip75B effects in adults. Previous studies showed that Eip75B is required for adult midgut cell proliferation in response to mating. To test the possible role of Eip75B in mediating the lifespan effects of mating and mifepristone, a tripartite FLP-recombinase-based conditional system was employed that provides controls for genetic background. Expression of a Hsp70-FLP transgene was induced in third instar larvae by a brief heat pulse. The FLP recombinase catalyzed the recombination and activation of an Actin5C-GAL4 transgene. The GAL4 transcription factor in turn activated expression of a UAS-Eip75B-RNAi transgene. Inhibition of Eip75B activity was confirmed by loss of midgut hypertrophy upon mating, and the lifespan effects of both mating and mifepristone were eliminated. In addition, the negative effects of mifepristone on egg production were eliminated. The data indicate that Eip75B mediates the effects of mating and mifepristone on female midgut hypertrophy, egg production, and lifespan.
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Affiliation(s)
| | | | | | | | | | | | - John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089-2910, USA
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2
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Xu X, Li T, Zhang L, Liu X. Effect of silencing the E74B gene on the development and metamorphosis of Helicoverpa armigera. PEST MANAGEMENT SCIENCE 2024; 80:1435-1445. [PMID: 37939129 DOI: 10.1002/ps.7874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/29/2023] [Accepted: 11/09/2023] [Indexed: 11/10/2023]
Abstract
BACKGROUND The growth and development transition of insects are mainly mediated by ecdysone. As one of the ecdysone-induced transcription factors, E74 is involved in many physiological processes of insect growth and development. However, E74 and its function in Helicoverpa armigera remains unclear. RESULTS In this study, E74B, a subtype of the E74, was identified for the first time in H. armigera. Bioinformatics analysis showed that H. armigera E74B shared the highest homology with E74B in Bombyx mori, which belongs to the E26 transformation-specific (ETS) superfamily. The expression profile showed that the transcription level of HaE74B increased in the late stages of fourth to sixth instars compared with the early stages; it was also high in the pupa and midgut. Moreover, we investigated the function of HaE74B through RNA interference and 20E rescue experiments. The results showed silencing of E74B affected the molting and growth of larvae, resulting in the death of more than 60% of larvae. In addition, it also seriously affected the metamorphosis of H. armigera, which reduced the pupae rate, the eclosion rate of the pupae, and fecundity. Application of 20E partially restored the defects in the molting, development and pupae rate of H. armigera. CONCLUSION Taken together, these results demonstrated that HaE74B plays a critical role in the growth, development, and metamorphosis of H. armigera, which serves as a molecular target and sets out a theoretical foundation for RNAi-mediated control of this key pest. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Xinhui Xu
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Tingting Li
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Lianjun Zhang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, China
| | - Xiaoning Liu
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, China
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3
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Cavigliasso F, Savitsky M, Koval A, Erkosar B, Savary L, Gallart-Ayala H, Ivanisevic J, Katanaev VL, Kawecki TJ. Cis-regulatory polymorphism at fiz ecdysone oxidase contributes to polygenic evolutionary response to malnutrition in Drosophila. PLoS Genet 2024; 20:e1011204. [PMID: 38452112 PMCID: PMC10962836 DOI: 10.1371/journal.pgen.1011204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 03/25/2024] [Accepted: 02/29/2024] [Indexed: 03/09/2024] Open
Abstract
We investigate the contribution of a candidate gene, fiz (fezzik), to complex polygenic adaptation to juvenile malnutrition in Drosophila melanogaster. Experimental populations maintained for >250 generations of experimental evolution to a nutritionally poor larval diet (Selected populations) evolved several-fold lower fiz expression compared to unselected Control populations. Here we show that this divergence in fiz expression is mediated by a cis-regulatory polymorphism. This polymorphism, originally sampled from a natural population in Switzerland, is distinct from a second cis-regulatory SNP previously identified in non-African D. melanogaster populations, implying that two independent cis-regulatory variants promoting high fiz expression segregate in non-African populations. Enzymatic analyses of Fiz protein expressed in E. coli demonstrate that it has ecdysone oxidase activity acting on both ecdysone and 20-hydroxyecdysone. Four of five fiz paralogs annotated to ecdysteroid metabolism also show reduced expression in Selected larvae, implying that malnutrition-driven selection favored general downregulation of ecdysone oxidases. Finally, as an independent test of the role of fiz in poor diet adaptation, we show that fiz knockdown by RNAi results in faster larval growth on the poor diet, but at the cost of greatly reduced survival. These results imply that downregulation of fiz in Selected populations was favored by selection on the nutritionally poor diet because of its role in suppressing growth in response to nutrient shortage. However, they suggest that fiz downregulation is only adaptive in combination with other changes evolved by Selected populations, which ensure that the organism can sustain the faster growth promoted by fiz downregulation.
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Affiliation(s)
- Fanny Cavigliasso
- Department of Ecology and Evolution, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Mikhail Savitsky
- HumanaFly Facility, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Alexey Koval
- Translational Research Centre in Oncohaematology, Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Berra Erkosar
- Department of Ecology and Evolution, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Loriane Savary
- Department of Ecology and Evolution, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Hector Gallart-Ayala
- Metabolomics Unit, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Julijana Ivanisevic
- Metabolomics Unit, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Vladimir L. Katanaev
- Translational Research Centre in Oncohaematology, Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Tadeusz J. Kawecki
- Department of Ecology and Evolution, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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4
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Heidarian Y, Tourigny JP, Fasteen TD, Mahmoudzadeh NH, Hurlburt AJ, Nemkov T, Reisz JA, D’Alessandro A, Tennessen JM. Metabolomic analysis of Drosophila melanogaster larvae lacking pyruvate kinase. G3 (BETHESDA, MD.) 2023; 14:jkad228. [PMID: 37792629 PMCID: PMC10755183 DOI: 10.1093/g3journal/jkad228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/02/2023] [Accepted: 09/24/2023] [Indexed: 10/06/2023]
Abstract
Pyruvate kinase (Pyk) is a rate-limiting enzyme that catalyzes the final metabolic reaction in glycolysis. The importance of this enzyme, however, extends far beyond ATP production, as Pyk is also known to regulate tissue growth, cell proliferation, and development. Studies of this enzyme in Drosophila melanogaster are complicated by the fact that the fly genome encodes 6 Pyk paralogs whose functions remain poorly defined. To address this issue, we used sequence distance and phylogenetic approaches to demonstrate that the gene Pyk encodes the enzyme most similar to the mammalian Pyk orthologs, while the other 5 Drosophila Pyk paralogs have significantly diverged from the canonical enzyme. Consistent with this observation, metabolomic studies of 2 different Pyk mutant strains revealed that larvae lacking Pyk exhibit a severe block in glycolysis, with a buildup of glycolytic intermediates upstream of pyruvate. However, our analysis also unexpectedly reveals that pyruvate levels are unchanged in Pyk mutants, indicating that larval metabolism maintains pyruvate pool size despite severe metabolic limitations. Consistent with our metabolomic findings, a complementary RNA-seq analysis revealed that genes involved in lipid metabolism and protease activity are elevated in Pyk mutants, again indicating that loss of this glycolytic enzyme induces compensatory changes in other aspects of metabolism. Overall, our study provides both insight into how Drosophila larval metabolism adapts to disruption of glycolytic metabolism as well as immediate clinical relevance, considering that Pyk deficiency is the most common congenital enzymatic defect in humans.
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Affiliation(s)
- Yasaman Heidarian
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Jason P Tourigny
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Tess D Fasteen
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | | | | | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Angelo D’Alessandro
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jason M Tennessen
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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5
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Li Y, Pan L, Li P, Gao F, Wang L, Chen J, Li Z, Gao Y, Gong Y, Jin F. Isolation of Enterococcus faecium and determination of its mechanism for promoting the growth and development of Drosophila. Sci Rep 2023; 13:18726. [PMID: 37907538 PMCID: PMC10618532 DOI: 10.1038/s41598-023-43727-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 09/27/2023] [Indexed: 11/02/2023] Open
Abstract
Intestinal symbiotic microorganisms have a strong capacity to regulate the physiological functions of their host, and Drosophila serves as a useful model. Enterococcus faecium (E. faecium) is a member of the normal intestinal flora of animals. Lactic acid bacteria (LAB) such as E. faecium can promote the growth and development of Drosophila, but the mechanism of regulation of Drosophila is poorly understood. In this study, we found that E. faecium used a carbon source to produce probiotic acids. E. faecium is a symbiotic bacterium for Drosophila, and adult flies passed on parental flora to offspring. E. faecium promoted the growth and development of Drosophila, especially under poor nutritional conditions. E. faecium shortened the developmental process for Drosophila and accelerated the transformation from larva to pupa. Finally, E. faecium promoted the growth and development of Drosophila through TOR and insulin signalling pathways.
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Affiliation(s)
- Yujuan Li
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Lei Pan
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Pengcheng Li
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Fuguo Gao
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Lei Wang
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Jian Chen
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Zhichao Li
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China
| | - Yongheng Gao
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China.
| | - Yumei Gong
- Department of Surgery, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany.
| | - Faguang Jin
- Department of Respiratory and Critical Care Medicine, Tangdu Hospital of Air Force Military Medical University, Xi'an, Shaanxi, China.
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6
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Heidarian Y, Tourigny JP, Fasteen TD, Mahmoudzadeh NH, Hurlburt AJ, Nemkov T, Reisz JA, D'Alessandro A, Tennessen JM. Metabolomic analysis of Drosophila melanogaster larvae lacking Pyruvate kinase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543743. [PMID: 37333180 PMCID: PMC10274742 DOI: 10.1101/2023.06.05.543743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Pyruvate kinase (Pyk) is a rate-limiting enzyme that catalyzes the final metabolic reaction in glycolysis. The importance of this enzyme, however, extends far beyond ATP production, as Pyk is also known to regulate tissue growth, cell proliferation, and development. Studies of this enzyme in Drosophila melanogaster , however, are complicated by the fact that the fly genome encodes six Pyk paralogs whose functions remain poorly defined. To address this issue, we used sequence distance and phylogenetic approaches to demonstrate that the gene Pyk encodes the enzyme most similar to the mammalian Pyk orthologs, while the other five Drosophila Pyk paralogs have significantly diverged from the canonical enzyme. Consistent with this observation, metabolomic studies of two different Pyk mutant backgrounds revealed that larvae lacking Pyk exhibit a severe block in glycolysis, with a buildup of glycolytic intermediates upstream of pyruvate. However, our analysis also unexpectedly reveals that steady state pyruvate levels are unchanged in Pyk mutants, indicating that larval metabolism maintains pyruvate pool size despite severe metabolic limitations. Consistent with our metabolomic findings, a complementary RNA-seq analysis revealed that genes involved in lipid metabolism and peptidase activity are elevated in Pyk mutants, again indicating that loss of this glycolytic enzyme induces compensatory changes in other aspects of metabolism. Overall, our study provides both insight into how Drosophila larval metabolism adapts to disruption of glycolytic metabolism as well as immediate clinical relevance, considering that Pyk deficiency is the most common congenital enzymatic defect in humans.
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Affiliation(s)
- Yasaman Heidarian
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Jason P Tourigny
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Tess D Fasteen
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | | | | | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jason M Tennessen
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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7
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Truman JW, Riddiford LM. Drosophila postembryonic nervous system development: a model for the endocrine control of development. Genetics 2023; 223:iyac184. [PMID: 36645270 PMCID: PMC9991519 DOI: 10.1093/genetics/iyac184] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/13/2022] [Indexed: 01/17/2023] Open
Abstract
During postembryonic life, hormones, including ecdysteroids, juvenile hormones, insulin-like peptides, and activin/TGFβ ligands act to transform the larval nervous system into an adult version, which is a fine-grained mosaic of recycled larval neurons and adult-specific neurons. Hormones provide both instructional signals that make cells competent to undergo developmental change and timing cues to evoke these changes across the nervous system. While touching on all the above hormones, our emphasis is on the ecdysteroids, ecdysone and 20-hydroxyecdysone (20E). These are the prime movers of insect molting and metamorphosis and are involved in all phases of nervous system development, including neurogenesis, pruning, arbor outgrowth, and cell death. Ecdysteroids appear as a series of steroid peaks that coordinate the larval molts and the different phases of metamorphosis. Each peak directs a stereotyped cascade of transcription factor expression. The cascade components then direct temporal programs of effector gene expression, but the latter vary markedly according to tissue and life stage. The neurons read the ecdysteroid titer through various isoforms of the ecdysone receptor, a nuclear hormone receptor. For example, at metamorphosis the pruning of larval neurons is mediated through the B isoforms, which have strong activation functions, whereas subsequent outgrowth is mediated through the A isoform through which ecdysteroids play a permissive role to allow local tissue interactions to direct outgrowth. The major circulating ecdysteroid can also change through development. During adult development ecdysone promotes early adult patterning and differentiation while its metabolite, 20E, later evokes terminal adult differentiation.
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Affiliation(s)
- James W Truman
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
| | - Lynn M Riddiford
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
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8
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Zhang B, Yao B, Li X, Jing T, Zhang S, Zou H, Zhang G, Zou C. E74 knockdown represses larval development and chitin synthesis in Hyphantria cunea. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 187:105216. [PMID: 36127058 DOI: 10.1016/j.pestbp.2022.105216] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/09/2022] [Accepted: 08/21/2022] [Indexed: 06/15/2023]
Abstract
E74 is a key transcription factor induced by 20E, which plays a broad role in many physiological events during insect growth and development, including vitellogenesis, organ remodeling and new tissue formation, programmed cell death and metamorphosis. However, whether it is involved in regulating insect chitin biosynthesis remains largely unclear. Here, the E74 gene was identified for the first time from Hyphantria cunea, a notorious defoliator of forestry. Thereafter, the role of HcE74 in regulating growth, development and chitin synthesis in H. cunea larvae was evaluated. Bioinformatics analysis showed that HcE74 shared the highest identity (95.53%) with E74A of Spodoptera litura, which belonged to Ets superfamily. The results of RNAi bioassay showed that the larval mortality on 6 d after HcE74 knockdown was up to 51.11 ± 6.94%. Meanwhile, a distinct developmental deformity phenotype was found when HcE74 was silenced. These results indicated that HcE74 plays an important role in the development and molting of H. cunea larvae. Moreover, HcE74 knockdown also significantly decreased the expression of four key genes related to chitin synthesis, including glucose-6-phosphate isomerase (HcG6PI), UDP-N-acetylglucosamine pyrophosphorylase (HcUAP), chitin synthetase A (HcCHSA), and chitin synthetase B (HcCHSB). As a result, the content of chitin in midgut and epidermis decreased by 0.54- and 0.08-fold, respectively. Taken together, these results demonstrated that HcE74 not only plays a critical role in the growth and molting of H. cunea larvae, but also probably participates in the transcriptional regulation of genes involved in chitin biosynthesis.
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Affiliation(s)
- Bihan Zhang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Bin Yao
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Xingpeng Li
- School of Forestry, Beihua University, Jilin 132013, PR China
| | - Tianzhong Jing
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Shengyu Zhang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Hang Zou
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Guocai Zhang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Chuanshan Zou
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China.
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9
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Ghosh S, Leng W, Wilsch-Bräuninger M, Barrera-Velázquez M, Léopold P, Eaton S. A local insulin reservoir in Drosophila alpha cell homologs ensures developmental progression under nutrient shortage. Curr Biol 2022; 32:1788-1797.e5. [PMID: 35316653 DOI: 10.1016/j.cub.2022.02.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/21/2021] [Accepted: 02/23/2022] [Indexed: 12/19/2022]
Abstract
Insulin/insulin-like growth factor (IGF) signaling (IIS) controls many aspects of development and physiology. In Drosophila, a conserved family of insulin-like peptides called Dilps is produced by brain neurosecretory cells, and it regulates organismal growth and developmental timing. To accomplish these systemic functions, the Dilps are secreted into the general circulation, and they signal to peripheral tissues in an endocrine fashion. Here, we describe the local uptake and storage of Dilps in the corpora cardiaca (CC), an endocrine organ composed of alpha cell homologs known to produce the glucagon-like adipokinetic hormone (AKH). We show that Dilp uptake by the CC relies on the expression of an IGF-binding protein called ImpL2. Following their uptake, immunogold staining demonstrates that Dilps are co-packaged with AKH in dense-core vesicles for secretion. In response to nutrient shortage, this specific Dilp reservoir is released and activates IIS in a paracrine manner in the prothoracic gland. This stimulates the production of the steroid hormone ecdysone and initiates entry into pupal development. We therefore uncover a sparing mechanism whereby insulin stores in CC serve to locally activate IIS and the production of ecdysone in the PG, accelerating developmental progression in adverse food conditions.
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Affiliation(s)
- Suhrid Ghosh
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany; Biotechnologisches Zentrum, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany.
| | - Weihua Leng
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Michaela Wilsch-Bräuninger
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Mariana Barrera-Velázquez
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany; Undergraduate Program on Genomic Sciences, Centro de Ciencias Genómicas, UNAM, Cuernavaca, Morelos 62210, Mexico
| | - Pierre Léopold
- Institut Curie, PSL Research University, CNRS UMR3215, Inserm U934, 26 Rue d'Ulm, 75005 Paris, France.
| | - Suzanne Eaton
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany; Biotechnologisches Zentrum, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
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10
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Lam G, Nam HJ, Velentzas PD, Baehrecke EH, Thummel CS. Drosophila E93 promotes adult development and suppresses larval responses to ecdysone during metamorphosis. Dev Biol 2022; 481:104-115. [PMID: 34648816 PMCID: PMC8665130 DOI: 10.1016/j.ydbio.2021.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 01/03/2023]
Abstract
Pulses of the steroid hormone ecdysone act through transcriptional cascades to direct the major developmental transitions during the Drosophila life cycle. These include the prepupal ecdysone pulse, which occurs 10 hours after pupariation and triggers the onset of adult morphogenesis and larval tissue destruction. E93 encodes a transcription factor that is specifically induced by the prepupal pulse of ecdysone, supporting a model proposed by earlier work that it specifies the onset of adult development. Although a number of studies have addressed these functions for E93, little is known about its roles in the salivary gland where the E93 locus was originally identified. Here we show that E93 is required for development through late pupal stages, with mutants displaying defects in adult differentiation and no detectable effect on the destruction of larval salivary glands. RNA-seq analysis demonstrates that E93 regulates genes involved in development and morphogenesis in the salivary glands, but has little effect on cell death gene expression. We also show that E93 is required to direct the proper timing of ecdysone-regulated gene expression in salivary glands, and that it suppresses earlier transcriptional programs that occur during larval and prepupal stages. These studies support the model that the stage-specific induction of E93 in late prepupae provides a critical signal that defines the end of larval development and the onset of adult differentiation.
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Affiliation(s)
- Geanette Lam
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 5100, Salt Lake City, UT 84112 USA
| | - Hyuck-Jin Nam
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 5100, Salt Lake City, UT 84112 USA
| | - Panagiotis D. Velentzas
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605 USA
| | - Eric H. Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605 USA
| | - Carl S. Thummel
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 5100, Salt Lake City, UT 84112 USA,Corresponding author. (C.S. Thummel)
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11
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Rice C, Macdonald SJ, Wang X, Ward RE. The Broad Transcription Factor Links Hormonal Signaling, Gene Expression, and Cellular Morphogenesis Events During Drosophila Imaginal Disc Development. Genetics 2020; 216:1137-1152. [PMID: 33115752 PMCID: PMC7768262 DOI: 10.1534/genetics.120.303717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 10/05/2020] [Indexed: 11/18/2022] Open
Abstract
Imaginal disc morphogenesis during metamorphosis in Drosophila melanogaster provides an excellent model to uncover molecular mechanisms by which hormonal signals effect physical changes during development. The broad (br) Z2 isoform encodes a transcription factor required for disc morphogenesis in response to 20-hydroxyecdysone, yet how it accomplishes this remains largely unknown. Here, we use functional studies of amorphic br5 mutants and a transcriptional target approach to identify processes driven by br and its regulatory targets in leg imaginal discs. br5 mutants fail to properly remodel their basal extracellular matrix (ECM) between 4 and 7 hr after puparium formation. Additionally, br5 mutant discs do not undergo the cell shape changes necessary for leg elongation and fail to elongate normally when exposed to the protease trypsin. RNA-sequencing of wild-type and br5 mutant leg discs identified 717 genes differentially regulated by br, including a large number of genes involved in glycolysis, and genes that encode proteins that interact with the ECM. RNA interference-based functional studies reveal that several of these genes are required for adult leg formation, particularly those involved in remodeling the ECM. Additionally, brZ2 expression is abruptly shut down at the onset of metamorphosis, and expressing it beyond this time results in failure of leg development during the late prepupal and pupal stages. Taken together, our results suggest that brZ2 is required to drive ECM remodeling, change cell shape, and maintain metabolic activity through the midprepupal stage, but must be switched off to allow expression of pupation genes.
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Affiliation(s)
- Clinton Rice
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Stuart J Macdonald
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Xiaochen Wang
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Robert E Ward
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
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12
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Abstract
The evolution of insect metamorphosis is one of the most important sagas in animal history, transforming small, obscure soil arthropods into a dominant terrestrial group that has profoundly shaped the evolution of terrestrial life. The evolution of flight initiated the trajectory towards metamorphosis, favoring enhanced differences between juvenile and adult stages. The initial step modified postembryonic development, resulting in the nymph-adult differences characteristic of hemimetabolous species. The second step was to complete metamorphosis, holometaboly, and occurred by profoundly altering embryogenesis to produce a larval stage, the nymph becoming the pupa to accommodate the deferred development needed to make the adult. These changing life history patterns were intimately linked to two hormonal systems, the ecdysteroids and the juvenile hormones (JH), which function in both embryonic and postembryonic domains and control the stage-specifying genes Krüppel homolog 1 (Kr-h1), broad and E93. The ecdysteroids induce and direct molting through the ecdysone receptor (EcR), a nuclear hormone receptor with numerous targets including a conserved transcription factor network, the 'Ashburner cascade', which translates features of the ecdysteroid peak into the different phases of the molt. With the evolution of metamorphosis, ecdysteroids acquired a metamorphic function that exploited the repressor capacity of the unliganded EcR, making it a hormone-controlled gateway for the tissue development preceding metamorphosis. JH directs ecdysteroid action, controlling Kr-h1 expression which in turn regulates the other stage-specifying genes. JH appears in basal insect groups as their embryos shift from growth and patterning to differentiation. As a major portion of embryogenesis was deferred to postembryonic life with the evolution of holometaboly, JH also acquired a potent role in regulating postembryonic growth and development. Details of its involvement in broad expression and E93 suppression have been modified as life cycles became more complex and likely underlie some of the changes seen in the shift from incomplete to complete metamorphosis.
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Affiliation(s)
- James W Truman
- Department of Biology and Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA.
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13
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Zipper L, Jassmann D, Burgmer S, Görlich B, Reiff T. Ecdysone steroid hormone remote controls intestinal stem cell fate decisions via the PPARγ-homolog Eip75B in Drosophila. eLife 2020; 9:e55795. [PMID: 32773037 PMCID: PMC7440922 DOI: 10.7554/elife.55795] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 08/07/2020] [Indexed: 12/27/2022] Open
Abstract
Developmental studies revealed fundamental principles on how organ size and function is achieved, but less is known about organ adaptation to new physiological demands. In fruit flies, juvenile hormone (JH) induces intestinal stem cell (ISC) driven absorptive epithelial expansion balancing energy uptake with increased energy demands of pregnancy. Here, we show 20-Hydroxy-Ecdysone (20HE)-signaling controlling organ homeostasis with physiological and pathological implications. Upon mating, 20HE titer in ovaries and hemolymph are increased and act on nearby midgut progenitors inducing Ecdysone-induced-protein-75B (Eip75B). Strikingly, the PPARγ-homologue Eip75B drives ISC daughter cells towards absorptive enterocyte lineage ensuring epithelial growth. To our knowledge, this is the first time a systemic hormone is shown to direct local stem cell fate decisions. Given the protective, but mechanistically unclear role of steroid hormones in female colorectal cancer patients, our findings suggest a tumor-suppressive role for steroidal signaling by promoting postmitotic fate when local signaling is deteriorated.
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Affiliation(s)
- Lisa Zipper
- Institute of Genetics, Heinrich-Heine-UniversityDüsseldorfGermany
| | - Denise Jassmann
- Institute of Genetics, Heinrich-Heine-UniversityDüsseldorfGermany
| | - Sofie Burgmer
- Institute of Genetics, Heinrich-Heine-UniversityDüsseldorfGermany
| | - Bastian Görlich
- Institute of Genetics, Heinrich-Heine-UniversityDüsseldorfGermany
| | - Tobias Reiff
- Institute of Genetics, Heinrich-Heine-UniversityDüsseldorfGermany
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Glaser-Schmitt A, Parsch J. Functional characterization of adaptive variation within a cis-regulatory element influencing Drosophila melanogaster growth. PLoS Biol 2018; 16:e2004538. [PMID: 29324742 PMCID: PMC5783415 DOI: 10.1371/journal.pbio.2004538] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 01/24/2018] [Accepted: 12/18/2017] [Indexed: 11/18/2022] Open
Abstract
Gene expression variation is a major contributor to phenotypic diversity within species and is thought to play an important role in adaptation. However, examples of adaptive regulatory polymorphism are rare, especially those that have been characterized at both the molecular genetic level and the organismal level. In this study, we perform a functional analysis of the Drosophila melanogaster CG9509 enhancer, a cis-regulatory element that shows evidence of adaptive evolution in populations outside the species’ ancestral range in sub-Saharan Africa. Using site-directed mutagenesis and transgenic reporter gene assays, we determined that 3 single nucleotide polymorphisms are responsible for the difference in CG9509 expression that is observed between sub-Saharan African and cosmopolitan populations. Interestingly, while 2 of these variants appear to have been the targets of a selective sweep outside of sub-Saharan Africa, the variant with the largest effect on expression remains polymorphic in cosmopolitan populations, suggesting it may be subject to a different mode of selection. To elucidate the function of CG9509, we performed a series of functional and tolerance assays on flies in which CG9509 expression was disrupted. We found that CG9509 plays a role in larval growth and influences adult body and wing size, as well as wing loading. Furthermore, variation in several of these traits was associated with variation within the CG9509 enhancer. The effect on growth appears to result from a modulation of active ecdysone levels and expression of growth factors. Taken together, our findings suggest that selection acted on 3 sites within the CG9509 enhancer to increase CG9509 expression and, as a result, reduce wing loading as D. melanogaster expanded out of sub-Saharan Africa. Much of the phenotypic variation that is observed within species is thought to be caused by variation in gene expression. Variants within cis-regulatory elements, which affect the expression of nearby genes within the same DNA strand, are thought to be an abundant resource upon which natural selection can act. Understanding the functional consequences of adaptive cis-regulatory changes is important, as it can help elucidate the mechanisms underlying phenotypic evolution in general and provide insight into the development and maintenance of biodiversity. However, functional analyses of these types of changes remain rare. Here we present a functional analysis of an adaptively evolving enhancer element of a D. melanogaster gene called CG9509, of previously unknown function. We show that 3 single nucleotide polymorphisms located within the enhancer of this gene are responsible for an increase in CG9509 expression in cosmopolitan populations (outside of south and central Africa) relative to sub-Saharan populations, which include ancestral populations. We further show that CG9509 is involved in the regulation of growth rate and body size determination and propose that the CG9509 enhancer underwent positive selection to reduce wing loading as the species expanded out of sub-Saharan Africa.
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Affiliation(s)
- Amanda Glaser-Schmitt
- Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
- * E-mail: (AGS); (JP)
| | - John Parsch
- Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
- * E-mail: (AGS); (JP)
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15
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Palu RA, Praggastis SA, Thummel CS. Parental obesity leads to metabolic changes in the F2 generation in Drosophila. Mol Metab 2017; 6:631-639. [PMID: 28702320 PMCID: PMC5485226 DOI: 10.1016/j.molmet.2017.03.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 01/15/2023] Open
Abstract
OBJECTIVE A significant portion of the heritable risk for complex metabolic disorders cannot be attributed to classic Mendelian genetic factors. At least some of this missing heritability is thought to be due to the epigenetic influence of parental and grandparental metabolic state on offspring health. Previous work suggests that this transgenerational phenomenon is evolutionarily conserved in Drosophila. These studies, however, have all depended on dietary paradigms to alter parental metabolic state, which can have inconsistent heritable effects on the metabolism of offspring. METHODS Here we use AKHR null alleles to induce obesity in the parental generation and then score both metabolic parameters and genome-wide transcriptional responses in AKHR heterozygote F1 progeny and genetically wild-type F2 progeny. RESULTS Unexpectedly, we observe elevated glycogen levels and changes in gene expression in AKHR heterozygotes due to haploinsufficiency at this locus. We also show that genetic manipulation of parental metabolism using AKHR mutations results in significant physiological changes in F2 wild-type offspring of the grandpaternal/maternal lineage. CONCLUSIONS Our results demonstrate that genetic manipulation of parental metabolism in Drosophila can have an effect on the health of F2 progeny, providing a non-dietary paradigm to better understand the mechanisms behind the transgenerational inheritance of metabolic state.
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Affiliation(s)
| | | | - Carl S. Thummel
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 5100, Salt Lake City, UT 84112-5330, USA
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16
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Abstract
Mosquitoes host communities of microbes in their digestive tract that consist primarily of bacteria. We previously reported that several mosquito species, including Aedes aegypti, do not develop beyond the first instar when fed a nutritionally complete diet in the absence of a gut microbiota. In contrast, several species of bacteria, including Escherichia coli, rescue development of axenic larvae into adults. The molecular mechanisms underlying bacteria-dependent growth are unknown. Here, we designed a genetic screen around E. coli that identified high-affinity cytochrome bd oxidase as an essential bacterial gene product for mosquito growth. Bioassays showed that bacteria in nonsterile larvae and gnotobiotic larvae inoculated with wild-type E. coli reduced midgut oxygen levels below 5%, whereas larvae inoculated with E. coli mutants defective for cytochrome bd oxidase did not. Experiments further supported that hypoxia leads to growth and ecdysone-induced molting. Altogether, our results identify aerobic respiration by bacteria as a previously unknown but essential process for mosquito development.
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Sun W, Wang CF, Zhang Z. Transcription factor E74A affects the ecdysone titer by regulating the expression of the EO gene in the silkworm, Bomby mori. Biochim Biophys Acta Gen Subj 2017; 1861:551-558. [DOI: 10.1016/j.bbagen.2016.11.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 11/07/2016] [Accepted: 11/11/2016] [Indexed: 01/18/2023]
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18
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Sengupta S, Rath U, Yao C, Zavortink M, Wang C, Girton J, Johansen KM, Johansen J. Digitor/dASCIZ Has Multiple Roles in Drosophila Development. PLoS One 2016; 11:e0166829. [PMID: 27861562 PMCID: PMC5115829 DOI: 10.1371/journal.pone.0166829] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/05/2016] [Indexed: 12/02/2022] Open
Abstract
In this study we provide evidence that the spindle matrix protein Skeletor in Drosophila interacts with the human ASCIZ (also known as ATMIN and ZNF822) ortholog, Digitor/dASCIZ. This interaction was first detected in a yeast two-hybrid screen and subsequently confirmed by pull-down assays. We also confirm a previously documented function of Digitor/dASCIZ as a regulator of Dynein light chain/Cut up expression. Using transgenic expression of a mCitrine-labeled Digitor construct, we show that Digitor/dASCIZ is a nuclear protein that is localized to interband and developmental puff chromosomal regions during interphase but redistributes to the spindle region during mitosis. Its mitotic localization and physical interaction with Skeletor suggest the possibility that Digitor/dASCIZ plays a direct role in mitotic progression as a member of the spindle matrix complex. Furthermore, we have characterized a P-element insertion that is likely to be a true null Digitor/dASCIZ allele resulting in complete pupal lethality when homozygous, indicating that Digitor/dASCIZ is an essential gene. Phenotypic analysis of the mutant provided evidence that Digitor/dASCIZ plays critical roles in regulation of metamorphosis and organogenesis as well as in the DNA damage response. In the Digitor/dASCIZ null mutant larvae there was greatly elevated levels of γH2Av, indicating accumulation of DNA double-strand breaks. Furthermore, reduced levels of Digitor/dASCIZ decreased the resistance to paraquat-induced oxidative stress resulting in increased mortality in a stress test paradigm. We show that an early developmental consequence of the absence of Digitor/dASCIZ is reduced third instar larval brain size although overall larval development appeared otherwise normal at this stage. While Digitor/dASCIZ mutant larvae initiate pupation, all mutant pupae failed to eclose and exhibited various defects in metamorphosis such as impaired differentiation, incomplete disc eversion, and faulty apoptosis. Altogether we provide evidence that Digitor/dASCIZ is a nuclear protein that performs multiple roles in Drosophila larval and pupal development.
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Affiliation(s)
- Saheli Sengupta
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Uttama Rath
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Changfu Yao
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Michael Zavortink
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Chao Wang
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Jack Girton
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Kristen M. Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
- * E-mail: (JJ); (KMJ)
| | - Jørgen Johansen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
- * E-mail: (JJ); (KMJ)
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19
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Palu RAS, Thummel CS. Sir2 Acts through Hepatocyte Nuclear Factor 4 to maintain insulin Signaling and Metabolic Homeostasis in Drosophila. PLoS Genet 2016; 12:e1005978. [PMID: 27058248 PMCID: PMC4825955 DOI: 10.1371/journal.pgen.1005978] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/15/2016] [Indexed: 12/20/2022] Open
Abstract
SIRT1 is a member of the sirtuin family of NAD+-dependent deacetylases, which couple cellular metabolism to systemic physiology. Although studies in mouse models have defined a central role for SIRT1 in maintaining metabolic health, the molecular mechanisms remain unclear. Here we show that loss of the Drosophila SIRT1 homolog sir2 leads to the age-progressive onset of hyperglycemia, obesity, glucose intolerance, and insulin resistance. Tissue-specific functional studies show that Sir2 is both necessary and sufficient in the fat body (analogous to the mammalian liver) to maintain glucose homeostasis and peripheral insulin sensitivity. Transcriptional profiling of sir2 mutants by RNA-seq revealed a major overlap with genes regulated by the nuclear receptor Hepatocyte Nuclear Factor 4 (HNF4). Consistent with this, Drosophila HNF4 mutants display diabetic phenotypes similar to those of sir2 mutants, and protein levels for dHNF4 are reduced in sir2 mutant animals. We show that Sir2 exerts these effects by deacetylating and stabilizing dHNF4 through protein interactions. Increasing dHNF4 expression in sir2 mutants is sufficient to rescue their insulin signaling defects, defining this nuclear receptor as an important downstream effector of Sir2 signaling. This study demonstrates that the key metabolic activities of SIRT1 have been conserved through evolution, provides a genetic model for functional studies of phenotypes related to type 2 diabetes, and establishes HNF4 as a critical downstream target by which Sir2 maintains metabolic health.
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Affiliation(s)
- Rebecca A. S. Palu
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Carl S. Thummel
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
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20
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Planelló R, Herrero Ó, Gómez-Sande P, Ozáez I, Cobo F, Servia MJ. Ecdysone-Related Biomarkers of Toxicity in the Model Organism Chironomus riparius: Stage and Sex-Dependent Variations in Gene Expression Profiles. PLoS One 2015; 10:e0140239. [PMID: 26448051 PMCID: PMC4598127 DOI: 10.1371/journal.pone.0140239] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 09/23/2015] [Indexed: 12/26/2022] Open
Abstract
Despite being considered a model organism in toxicity studies, particularly in assessing the environmental impact of endocrine disrupting compounds (EDCs) and other chemicals, the molecular basis of development is largely unknown in Chironomus riparius. We have characterized the expression patterns of important genes involved in the ecdysone pathway from embryos to pupa, but specially during the different phases of C. riparius fourth larval instar, according to the development of genital and thoracic imaginal discs. Real-Time PCR was used to analyze: EcR and usp, two genes encoding the two dimerizing partners of the functional ecdysone receptor; E74, an early response gene induced by ecdysteroids; vg (vitellogenin), an effector gene; hsp70 and hsc70, two heat-shock genes involved in the correct folding of the ecdysone receptor; and rpL13, as a part of the ribosomal machinery. Our results show for the first time stage and sex-dependent variations in ecdysone-responsive genes, specially during the late larval stage of C. riparius. The induction in the expression of EcR and usp during the VII-VIII phase of the fourth instar is concomitant with a coordinated response in the activity of the other genes analyzed, suggesting the moment where larvae prepare for pupation. This work is particularly relevant given that most of the analyzed genes have been proposed previously in this species as sensitive biomarkers for the toxicological evaluation of aquatic ecosystems. Identifying the natural regulation of these molecular endpoints throughout the Chironomus development will contribute to a more in-depth and accurate evaluation of the disrupting effects of EDCs in ecotoxicological studies.
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Affiliation(s)
- Rosario Planelló
- Grupo de Biología y Toxicología Ambiental, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, UNED, Paseo de la Senda del Rey 9, 28040 Madrid, Spain
- * E-mail:
| | - Óscar Herrero
- Grupo de Biología y Toxicología Ambiental, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, UNED, Paseo de la Senda del Rey 9, 28040 Madrid, Spain
| | - Pablo Gómez-Sande
- Departamento de Zoología y Antropología Física, Universidad de Santiago de Compostela, USC, Campus Sur s/n, 15782 Santiago de Compostela, Spain
- Estación de Hidrobioloxía “Encoro do Con”, EHEC, Universidad de Santiago de Compostela, USC, Castroagudín s/n, 36617 Vilagarcía de Arousa, Pontevedra, Spain
| | - Irene Ozáez
- Grupo de Biología y Toxicología Ambiental, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, UNED, Paseo de la Senda del Rey 9, 28040 Madrid, Spain
| | - Fernando Cobo
- Departamento de Zoología y Antropología Física, Universidad de Santiago de Compostela, USC, Campus Sur s/n, 15782 Santiago de Compostela, Spain
- Estación de Hidrobioloxía “Encoro do Con”, EHEC, Universidad de Santiago de Compostela, USC, Castroagudín s/n, 36617 Vilagarcía de Arousa, Pontevedra, Spain
| | - María J. Servia
- Departamento de Biología Animal, Biología Vegetal y Ecología, Facultad de Ciencias, Universidade da Coruña, UDC, Campus da Zapateira s/n, 15008 A Coruña, Spain
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21
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Herboso L, Oliveira MM, Talamillo A, Pérez C, González M, Martín D, Sutherland JD, Shingleton AW, Mirth CK, Barrio R. Ecdysone promotes growth of imaginal discs through the regulation of Thor in D. melanogaster. Sci Rep 2015. [PMID: 26198204 PMCID: PMC4510524 DOI: 10.1038/srep12383] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Animals have a determined species-specific body size that results from the combined action of hormones and signaling pathways regulating growth rate and duration. In Drosophila, the steroid hormone ecdysone controls developmental transitions, thereby regulating the duration of the growth period. Here we show that ecdysone promotes the growth of imaginal discs in mid-third instar larvae, since imaginal discs from larvae with reduced or no ecdysone synthesis are smaller than wild type due to smaller and fewer cells. We show that insulin-like peptides are produced and secreted normally in larvae with reduced ecdysone synthesis, and upstream components of insulin/insulin-like signaling are activated in their discs. Instead, ecdysone appears to regulate the growth of imaginal discs via Thor/4E-BP, a negative growth regulator downstream of the insulin/insulin-like growth factor/Tor pathways. Discs from larvae with reduced ecdysone synthesis have elevated levels of Thor, while mutations in Thor partially rescue their growth. The regulation of organ growth by ecdysone is evolutionarily conserved in hemimetabolous insects, as shown by our results obtained using Blattella germanica. In summary, our data provide new insights into the relationship between components of the insulin/insulin-like/Tor and ecdysone pathways in the control of organ growth.
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Affiliation(s)
- Leire Herboso
- CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Marisa M Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Ana Talamillo
- CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Coralia Pérez
- CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - Monika González
- CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
| | - David Martín
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | | | | | - Christen K Mirth
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Rosa Barrio
- CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Bizkaia, Spain
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22
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Ali MS, Rahman RF, Swapon AH. Transcriptional regulation of cuticular protein glycine-rich13 gene expression in wing disc of Bombyx mori, Lepidoptera. JOURNAL OF INSECT SCIENCE (ONLINE) 2015; 15:iev019. [PMID: 25843580 PMCID: PMC4535481 DOI: 10.1093/jisesa/iev019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/14/2015] [Indexed: 06/04/2023]
Abstract
Cuticular protein genes are good models to study the molecular mechanisms of signaling by ecdysteroids, which regulate molting and metamorphosis in insects. The present research demonstrates on hormonal regulation and analysis of the regulatory sequences and transcription factors important for Bombyx mori cuticular protein glycine-rich13 (CPG13) gene expression. Expression of CPG13 was strong at prepupal stage in wing tissues of B. mori. CPG13 expression was induced by the addition of 20E, which was inhibited by cycloheximide in the wing disc. The upstream region of the CPG13 gene was analyzed using a transient reporter assay with a gene gun system and identified two BR-Z2 binding sites to be important cis-acting elements for the transcription activation of the luciferase reporter gene by an ecdysone pulse. Site-directed mutagenesis of these sites, followed by introduction into wing discs, significantly decreased the reporter activity. It was found that the regions carrying the binding sites for the ecdysone-responsive transcription factor BR-Z2 were responsible for the hormonal enhancement of the reporter gene activity in wing discs. Mutation of the BR-Z2 binding sites decreased the reporter activity suggesting that the BR-Z2 isoform can bind to the upstream region of the cuticle protein gene, CPG13 and activates its expression.
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Affiliation(s)
- Md Saheb Ali
- Bangladesh Jute Research Institute, Manik Mia Ave., Dhaka 1207, Bangladesh
| | - R F Rahman
- Bangladesh Jute Research Institute, Manik Mia Ave., Dhaka 1207, Bangladesh
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23
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Sap KA, Bezstarosti K, Dekkers DHW, van den Hout M, van Ijcken W, Rijkers E, Demmers JAA. Global quantitative proteomics reveals novel factors in the ecdysone signaling pathway in Drosophila melanogaster. Proteomics 2015; 15:725-38. [PMID: 25403936 DOI: 10.1002/pmic.201400308] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 09/19/2014] [Accepted: 11/12/2014] [Indexed: 01/06/2023]
Abstract
The ecdysone signaling pathway plays a major role in various developmental transitions in insects. Recent advances in the understanding of ecdysone action have relied to a large extent on the application of molecular genetic tools in Drosophila. Here, we used a comprehensive quantitative SILAC MS-based approach to study the global, dynamic proteome of a Drosophila cell line to investigate how hormonal signals are transduced into specific cellular responses. Global proteome data after ecdysone treatment after various time points were then integrated with transcriptome data. We observed a substantial overlap in terms of affected targets between the dynamic proteome and transcriptome, although there were some clear differences in timing effects. Also, downregulation of several specific mRNAs did not always correlate with downregulation of their corresponding protein counterparts, and in some cases there was no correlation between transcriptome and proteome dynamics whatsoever. In addition, we performed a comprehensive interactome analysis of EcR, the major target of ecdysone. Proteins copurified with EcR include factors involved in transcription, chromatin remodeling, ecdysone signaling, ecdysone biosynthesis, and other signaling pathways. Novel ecdysone-responsive proteins identified in this study might link previously unknown proteins to the ecdysone signaling pathway and might be novel targets for developmental studies. To our knowledge, this is the first time that ecdysone signaling is studied by global quantitative proteomics. All MS data have been deposited in the ProteomeXchange with identifier PXD001455 (http://proteomecentral.proteomexchange.org/dataset/PXD001455).
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Affiliation(s)
- Karen A Sap
- Proteomics Center, Erasmus University Medical Center, Rotterdam, The Netherlands; Netherlands Proteomics Center, Rotterdam, The Netherlands
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The PIKE homolog Centaurin gamma regulates developmental timing in Drosophila. PLoS One 2014; 9:e97332. [PMID: 24845618 PMCID: PMC4028201 DOI: 10.1371/journal.pone.0097332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 04/17/2014] [Indexed: 12/30/2022] Open
Abstract
Phosphoinositide-3-kinase enhancer (PIKE) proteins encoded by the PIKE/CENTG1 gene are members of the gamma subgroup of the Centaurin superfamily of small GTPases. They are characterized by their chimeric protein domain architecture consisting of a pleckstrin homology (PH) domain, a GTPase-activating (GAP) domain, Ankyrin repeats as well as an intrinsic GTPase domain. In mammals, three PIKE isoforms with variations in protein structure and subcellular localization are encoded by the PIKE locus. PIKE inactivation in mice results in a broad range of defects, including neuronal cell death during brain development and misregulation of mammary gland development. PIKE -/- mutant mice are smaller, contain less white adipose tissue, and show insulin resistance due to misregulation of AMP-activated protein kinase (AMPK) and insulin receptor/Akt signaling. here, we have studied the role of PIKE proteins in metabolic regulation in the fly. We show that the Drosophila PIKE homolog, ceng1A, encodes functional GTPases whose internal GAP domains catalyze their GTPase activity. To elucidate the biological function of ceng1A in flies, we introduced a deletion in the ceng1A gene by homologous recombination that removes all predicted functional PIKE domains. We found that homozygous ceng1A mutant animals survive to adulthood. In contrast to PIKE -/- mouse mutants, genetic ablation of Drosophila ceng1A does not result in growth defects or weight reduction. Although metabolic pathways such as insulin signaling, sensitivity towards starvation and mobilization of lipids under high fed conditions are not perturbed in ceng1A mutants, homozygous ceng1A mutants show a prolonged development in second instar larval stage, leading to a late onset of pupariation. In line with these results we found that expression of ecdysone inducible genes is reduced in ceng1A mutants. Together, we propose a novel role for Drosophila Ceng1A in regulating ecdysone signaling-dependent second to third instar larval transition.
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Coordinated metabolic transitions during Drosophila embryogenesis and the onset of aerobic glycolysis. G3-GENES GENOMES GENETICS 2014; 4:839-50. [PMID: 24622332 PMCID: PMC4025483 DOI: 10.1534/g3.114.010652] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Rapidly proliferating cells such as cancer cells and embryonic stem cells rely on a specialized metabolic program known as aerobic glycolysis, which supports biomass production from carbohydrates. The fruit fly Drosophila melanogaster also utilizes aerobic glycolysis to support the rapid growth that occurs during larval development. Here we use singular value decomposition analysis of modENCODE RNA-seq data combined with GC-MS-based metabolomic analysis to analyze the changes in gene expression and metabolism that occur during Drosophila embryogenesis, spanning the onset of aerobic glycolysis. Unexpectedly, we find that the most common pattern of co-expressed genes in embryos includes the global switch to glycolytic gene expression that occurs midway through embryogenesis. In contrast to the canonical aerobic glycolytic pathway, however, which is accompanied by reduced mitochondrial oxidative metabolism, the expression of genes involved in the tricarboxylic cycle (TCA cycle) and the electron transport chain are also upregulated at this time. Mitochondrial activity, however, appears to be attenuated, as embryos exhibit a block in the TCA cycle that results in elevated levels of citrate, isocitrate, and α-ketoglutarate. We also find that genes involved in lipid breakdown and β-oxidation are upregulated prior to the transcriptional initiation of glycolysis, but are downregulated before the onset of larval development, revealing coordinated use of lipids and carbohydrates during development. These observations demonstrate the efficient use of nutrient stores to support embryonic development, define sequential metabolic transitions during this stage, and demonstrate striking similarities between the metabolic state of late-stage fly embryos and tumor cells.
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Wang HB, Iwanaga M, Kawasaki H. Stage-specific activation of the E74B promoter by low ecdysone concentrations in the wing disc of Bombyx mori. Gene 2014; 537:322-7. [PMID: 24393712 DOI: 10.1016/j.gene.2013.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 11/26/2013] [Accepted: 12/02/2013] [Indexed: 11/27/2022]
Abstract
To understand the transcriptional regulation of E74B by low concentrations of ecdysone, the promoter activity of Bombyx mori E74B was assessed in the B. mori wing disc using a transient reporter assay. We identified the transcription start sites of BmE74B and found that the core promoter region consists of initiator (Inr) and downstream promoter elements (DPE). The 3.6-kb upstream promoter region of BmE74B was responsive to 20-hydroxyecdysone (20E) in a dose-dependent manner, and the highest luciferase activity was observed in the presence of 0.2 μg/ml 20E. Moreover, the upstream BmE74B promoter activity was induced by 20E in a stage-specific and time-dependent manner, and the 3.6-kb promoter contained essential elements for the temporal regulation of BmE74B. Furthermore, we found a set of putative ecdysone response elements (EcREs). Five of these elements are highly conserved, capable of binding to the ecdysone receptor. Mutation of more than three putative EcREs, followed by introduction into the wing discs, abolished the activation of the BmE74B promoter by a low concentration of ecdysone. The results confirmed the role of ecdysone response elements in the transcription regulation of BmE74B and demonstrated that multiple putative EcREs were involved in the maximum response of BmE74B to low concentrations of ecdysone.
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Affiliation(s)
- Hua-Bing Wang
- Faculty of Agriculture, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi 321-8505, Japan
| | - Masashi Iwanaga
- Faculty of Agriculture, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi 321-8505, Japan
| | - Hideki Kawasaki
- Faculty of Agriculture, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi 321-8505, Japan.
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Charroux B, Royet J. Mutations in the Drosophila ortholog of the vertebrate Golgi pH regulator (GPHR) protein disturb endoplasmic reticulum and Golgi organization and affect systemic growth. Biol Open 2014; 3:72-80. [PMID: 24357227 PMCID: PMC3892162 DOI: 10.1242/bio.20137187] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Sorting of secretory cargo and retrieval of components of the biosynthetic pathway occur in organelles such as the Golgi apparatus, the endoplasmic reticulum and the endosomes. In order to perform their functions in protein sorting, these organelles require a weakly acidified lumen. In vitro data have shown that Golgi luminal pH is in part regulated by an anion channel called Golgi pH Regulator (GPHR). Mammalian cells carrying a mutated GPHR version present an increased luminal pH leading to delayed protein transport, impaired glycosylation and Golgi disorganization. Using Drosophila as a model system, we present here the first phenotypic consequences, at the organism level, of a complete lack of GPHR function. We show that, although all individuals carrying complete loss-of-function mutations in the dGPHR gene can go through embryonic development, most of them die at late larval stages. The dGPHR mutations are, however, sublethal and can therefore generate escapers that are smaller than controls. Using cellular and molecular readouts, we demonstrate that the effects of dGPHR mutation on larval growth are not due to Insulin signaling pathway impairment and can be rescued by providing dGPHR in only some of the larval tissues. We reveal that, although functionally exchangeable, the invertebrate and vertebrate GPHRs display not completely overlapping sub-cellular localization. Whereas the mammalian GPHR is a Golgi-only associated protein whose inactivation disturbs the Golgi apparatus, our data suggest that dGPHR is expressed in both the ER and the Golgi and that dGPHR mutant flies have defects in both organelles that lead to a defective secretory pathway.
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Affiliation(s)
- Bernard Charroux
- Aix-Marseille Université, CNRS, Institut de Biologie du Développement de Marseille-Luminy UMR 7288, F-13288 Marseille, France
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SVD identifies transcript length distribution functions from DNA microarray data and reveals evolutionary forces globally affecting GBM metabolism. PLoS One 2013; 8:e78913. [PMID: 24282503 PMCID: PMC3839928 DOI: 10.1371/journal.pone.0078913] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/25/2013] [Indexed: 01/10/2023] Open
Abstract
To search for evolutionary forces that might act upon transcript length, we use the singular value decomposition (SVD) to identify the length distribution functions of sets and subsets of human and yeast transcripts from profiles of mRNA abundance levels across gel electrophoresis migration distances that were previously measured by DNA microarrays. We show that the SVD identifies the transcript length distribution functions as “asymmetric generalized coherent states” from the DNA microarray data and with no a-priori assumptions. Comparing subsets of human and yeast transcripts of the same gene ontology annotations, we find that in both disparate eukaryotes, transcripts involved in protein synthesis or mitochondrial metabolism are significantly shorter than typical, and in particular, significantly shorter than those involved in glucose metabolism. Comparing the subsets of human transcripts that are overexpressed in glioblastoma multiforme (GBM) or normal brain tissue samples from The Cancer Genome Atlas, we find that GBM maintains normal brain overexpression of significantly short transcripts, enriched in transcripts that are involved in protein synthesis or mitochondrial metabolism, but suppresses normal overexpression of significantly longer transcripts, enriched in transcripts that are involved in glucose metabolism and brain activity. These global relations among transcript length, cellular metabolism and tumor development suggest a previously unrecognized physical mode for tumor and normal cells to differentially regulate metabolism in a transcript length-dependent manner. The identified distribution functions support a previous hypothesis from mathematical modeling of evolutionary forces that act upon transcript length in the manner of the restoring force of the harmonic oscillator.
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The Drosophila COMPASS-like Cmi-Trr coactivator complex regulates dpp/BMP signaling in pattern formation. Dev Biol 2013; 380:185-98. [DOI: 10.1016/j.ydbio.2013.05.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/01/2013] [Accepted: 05/13/2013] [Indexed: 01/01/2023]
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30
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Ali MS, Iwanaga M, Kawasaki H. Ecdysone-responsive transcriptional regulation determines the temporal expression of cuticular protein genes in wing discs of Bombyx mori. Gene 2013; 512:337-47. [DOI: 10.1016/j.gene.2012.09.126] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 09/10/2012] [Accepted: 09/12/2012] [Indexed: 01/09/2023]
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Ou Q, King-Jones K. What goes up must come down: transcription factors have their say in making ecdysone pulses. Curr Top Dev Biol 2013; 103:35-71. [PMID: 23347515 DOI: 10.1016/b978-0-12-385979-2.00002-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Insect metamorphosis is one of the most fascinating biological processes in the animal kingdom. The dramatic transition from an immature juvenile to a reproductive adult is under the control of the steroid hormone ecdysone, also known as the insect molting hormone. During Drosophila development, periodic pulses of ecdysone are released from the prothoracic glands, upon which the hormone is rapidly converted in peripheral tissues to its biologically active form, 20-hydroxyecdysone. Each hormone pulse has a unique profile and causes different developmental events, but we only have a rudimentary understanding of how the timing, amplitude, and duration of a given pulse are controlled. A key component involved in the timing of ecdysone pulses is PTTH, a brain-derived neuropeptide. PTTH stimulates ecdysone production through a Ras/Raf/ERK signaling cascade; however, comparatively little is known about the downstream targets of this pathway. In recent years, it has become apparent that transcriptional regulation plays a critical role in regulating the synthesis of ecdysone, but only one transcription factor has a well-defined link to PTTH. Interestingly, many of the ecdysteroidogenic transcription factors were originally characterized as primary response genes in the ecdysone signaling cascade that elicits the biological responses to the hormone in target tissues. To review these developments, we will first provide an overview of the transcription factors that act in the Drosophila ecdysone regulatory hierarchy. We will then discuss the roles of these transcriptional regulators in controlling ecdysone synthesis. In the last section, we will briefly outline transcription factors that likely have roles in regulating ecdysone synthesis but have not been formally identified as downstream effectors of ecdysone.
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Affiliation(s)
- Qiuxiang Ou
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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Chauhan C, Zraly CB, Parilla M, Diaz MO, Dingwall AK. Histone recognition and nuclear receptor co-activator functions of Drosophila cara mitad, a homolog of the N-terminal portion of mammalian MLL2 and MLL3. Development 2012; 139:1997-2008. [PMID: 22569554 DOI: 10.1242/dev.076687] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
MLL2 and MLL3 histone lysine methyltransferases are conserved components of COMPASS-like co-activator complexes. In vertebrates, the paralogous MLL2 and MLL3 contain multiple domains required for epigenetic reading and writing of the histone code involved in hormone-stimulated gene programming, including receptor-binding motifs, SET methyltransferase, HMG and PHD domains. The genes encoding MLL2 and MLL3 arose from a common ancestor. Phylogenetic analyses reveal that the ancestral gene underwent a fission event in some Brachycera dipterans, including Drosophila species, creating two independent genes corresponding to the N- and C-terminal portions. In Drosophila, the C-terminal SET domain is encoded by trithorax-related (trr), which is required for hormone-dependent gene activation. We identified the cara mitad (cmi) gene, which encodes the previously undiscovered N-terminal region consisting of PHD and HMG domains and receptor-binding motifs. The cmi gene is essential and its functions are dosage sensitive. CMI associates with TRR, as well as the EcR-USP receptor, and is required for hormone-dependent transcription. Unexpectedly, although the CMI and MLL2 PHDf3 domains could bind histone H3, neither showed preference for trimethylated lysine 4. Genetic tests reveal that cmi is required for proper global trimethylation of H3K4 and that hormone-stimulated transcription requires chromatin binding by CMI, methylation of H3K4 by TRR and demethylation of H3K27 by the demethylase UTX. The evolutionary split of MLL2 into two distinct genes in Drosophila provides important insight into distinct epigenetic functions of conserved readers and writers of the histone code.
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Affiliation(s)
- Chhavi Chauhan
- Oncology Institute, Stritch School of Medicine, Loyola University of Chicago, Maywood, IL 60153, USA
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Bodai L, Zsindely N, Gáspár R, Kristó I, Komonyi O, Boros IM. Ecdysone induced gene expression is associated with acetylation of histone H3 lysine 23 in Drosophila melanogaster. PLoS One 2012; 7:e40565. [PMID: 22808194 PMCID: PMC3393682 DOI: 10.1371/journal.pone.0040565] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 06/09/2012] [Indexed: 11/24/2022] Open
Abstract
Posttranslational modification of histones regulates transcription but the exact role that acetylation of specific lysine residues plays in biological processes in vivo is still not clearly understood. To assess the contribution of different histone modifications to transcriptional activation in vivo, we determined the acetylation patterns on the ecdysone induced Eip74EF and Eip75B genes in Drosophila melanogaster larvae by chromatin immunoprecipitation. We found that acetylation of histone H3 lysine 23 is localized to promoters and correlates with endogenous ecdysone induced gene activation. In contrast, acetylation of lysines 8, 12 and 16 of histone H4 and lysine 9 of histone H3 showed minor differences in their distribution on the regulatory and transcribed regions tested, and had limited or no correlation with ecdysone induced transcriptional activity. We found that dCBP, which is encoded by the nejire gene, acetylates H3 lysine 23 in vivo, and silencing of nejire leads to reduced expression of the Eip74EF and Eip75B genes. Our results suggest that acetylation of specific lysine residues of histones contribute specifically to the dynamic regulation of transcription. Furthermore, along with previous studies identify CBP dependent H3 lysine 23 acetylation as an evolutionarily conserved chromatin modification involved in steroid induced gene activation.
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Affiliation(s)
- László Bodai
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.
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34
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Ono H, Morita S, Asakura I, Nishida R. Conversion of 3-oxo steroids into ecdysteroids triggers molting and expression of 20E-inducible genes in Drosophila melanogaster. Biochem Biophys Res Commun 2012; 421:561-6. [DOI: 10.1016/j.bbrc.2012.04.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 04/07/2012] [Indexed: 01/22/2023]
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35
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Ali MS, Wang HB, Iwanaga M, Kawasaki H. Expression of cuticular protein genes, BmorCPG11 and BMWCP5 is differently regulated at the pre-pupal stage in wing discs of Bombyx mori. Comp Biochem Physiol B Biochem Mol Biol 2012; 162:44-50. [DOI: 10.1016/j.cbpb.2012.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 02/13/2012] [Accepted: 02/13/2012] [Indexed: 01/02/2023]
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36
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Storelli G, Defaye A, Erkosar B, Hols P, Royet J, Leulier F. Lactobacillus plantarum promotes Drosophila systemic growth by modulating hormonal signals through TOR-dependent nutrient sensing. Cell Metab 2011; 14:403-14. [PMID: 21907145 DOI: 10.1016/j.cmet.2011.07.012] [Citation(s) in RCA: 515] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/24/2011] [Accepted: 07/14/2011] [Indexed: 02/08/2023]
Abstract
There is growing evidence that intestinal bacteria are important beneficial partners of their metazoan hosts. Recent observations suggest a strong link between commensal bacteria, host energy metabolism, and metabolic diseases such as diabetes and obesity. As a consequence, the gut microbiota is now considered a "host" factor that influences energy uptake. However, the impact of intestinal bacteria on other systemic physiological parameters still remains unclear. Here, we demonstrate that Drosophila microbiota promotes larval growth upon nutrient scarcity. We reveal that Lactobacillus plantarum, a commensal bacterium of the Drosophila intestine, is sufficient on its own to recapitulate the natural microbiota growth-promoting effect. L. plantarum exerts its benefit by acting genetically upstream of the TOR-dependent host nutrient sensing system controlling hormonal growth signaling. Our results indicate that the intestinal microbiota should also be envisaged as a factor that influences the systemic growth of its host.
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Affiliation(s)
- Gilles Storelli
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR 6216/Aix-Marseille Universités, 13288 Marseille, France
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Tennessen JM, Baker KD, Lam G, Evans J, Thummel CS. The Drosophila estrogen-related receptor directs a metabolic switch that supports developmental growth. Cell Metab 2011; 13:139-48. [PMID: 21284981 PMCID: PMC3072597 DOI: 10.1016/j.cmet.2011.01.005] [Citation(s) in RCA: 207] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 11/10/2010] [Accepted: 12/07/2010] [Indexed: 12/25/2022]
Abstract
Metabolism must be coordinated with development to provide the appropriate energetic needs for each stage in the life cycle. Little is known, however, about how this temporal control is achieved. Here, we show that the Drosophila ortholog of the estrogen-related receptor (ERR) family of nuclear receptors directs a critical metabolic transition during development. dERR mutants die as larvae with low ATP levels and elevated levels of circulating sugars. The expression of active dERR protein in mid-embryogenesis triggers a coordinate switch in gene expression that drives a metabolic program normally associated with proliferating cells, supporting the dramatic growth that occurs during larval development. This study shows that dERR plays a central role in carbohydrate metabolism, demonstrates that a proliferative metabolic program is used in normal developmental growth, and provides a molecular context to understand the close association between mammalian ERR family members and cancer.
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Affiliation(s)
- Jason M. Tennessen
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 2100, Salt Lake City, UT 84112-5330 USA
| | - Keith D. Baker
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 2100, Salt Lake City, UT 84112-5330 USA
| | - Geanette Lam
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 2100, Salt Lake City, UT 84112-5330 USA
| | - Janelle Evans
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 2100, Salt Lake City, UT 84112-5330 USA
| | - Carl S. Thummel
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 2100, Salt Lake City, UT 84112-5330 USA
- Correspondence:
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Ruaud AF, Lam G, Thummel CS. The Drosophila NR4A nuclear receptor DHR38 regulates carbohydrate metabolism and glycogen storage. Mol Endocrinol 2010; 25:83-91. [PMID: 21084378 DOI: 10.1210/me.2010-0337] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Animals balance nutrient storage and mobilization to maintain metabolic homeostasis, a process that is disrupted in metabolic diseases like obesity and diabetes. Here, we show that DHR38, the single fly ortholog of the mammalian nuclear receptor 4A family of nuclear receptors, regulates glycogen storage during the larval stages of Drosophila melanogaster. DHR38 is expressed and active in the gut and body wall of larvae, and its expression levels change in response to nutritional status. DHR38 null mutants have normal levels of glucose, trehalose (the major circulating form of sugar), and triacylglycerol but display reduced levels of glycogen in the body wall muscles, which constitute the primary storage site for carbohydrates. Microarray analysis reveals that many metabolic genes are mis-regulated in DHR38 mutants. These include phosphoglucomutase, which is required for glycogen synthesis, and the two genes that encode the digestive enzyme amylase, accounting for the reduced amylase enzyme activity seen in DHR38 mutant larvae. These studies demonstrate that a critical role of nuclear receptor 4A receptors in carbohydrate metabolism has been conserved through evolution and that nutritional regulation of DHR38 expression maintains the proper uptake and storage of glycogen during the growing larval stage of development.
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Fraichard S, Bougé AL, Kendall T, Chauvel I, Bouhin H, Bunch TA. Tenectin is a novel alphaPS2betaPS integrin ligand required for wing morphogenesis and male genital looping in Drosophila. Dev Biol 2010; 340:504-17. [PMID: 20152825 DOI: 10.1016/j.ydbio.2010.02.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 01/29/2010] [Accepted: 02/02/2010] [Indexed: 10/19/2022]
Abstract
Morphogenesis of the adult structures of holometabolous insects is regulated by ecdysteroids and juvenile hormones and involves cell-cell interactions mediated in part by the cell surface integrin receptors and their extracellular matrix (ECM) ligands. These adhesion molecules and their regulation by hormones are not well characterized. We describe the gene structure of a newly described ECM molecule, tenectin, and demonstrate that it is a hormonally regulated ECM protein required for proper morphogenesis of the adult wing and male genitalia. Tenectin's function as a new ligand of the PS2 integrins is demonstrated by both genetic interactions in the fly and by cell spreading and cell adhesion assays in cultured cells. Its interaction with the PS2 integrins is dependent on RGD and RGD-like motifs. Tenectin's function in looping morphogenesis in the development of the male genitalia led to experiments that demonstrate a role for PS integrins in the execution of left-right asymmetry.
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Affiliation(s)
- Stéphane Fraichard
- Centre des Sciences du Goût et de l'Alimentation, UMR-6265 CNRS, INRA, Université de Bourgogne, Agrosup Dijon, F-21000 Dijon, France
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40
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Ruaud AF, Lam G, Thummel CS. The Drosophila nuclear receptors DHR3 and betaFTZ-F1 control overlapping developmental responses in late embryos. Development 2010; 137:123-31. [PMID: 20023167 DOI: 10.1242/dev.042036] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Studies of the onset of metamorphosis have identified an ecdysone-triggered transcriptional cascade that consists of the sequential expression of the transcription-factor-encoding genes DHR3, betaFTZ-F1, E74A and E75A. Although the regulatory interactions between these genes have been well characterized by genetic and molecular studies over the past 20 years, their developmental functions have remained more poorly understood. In addition, a transcriptional sequence similar to that observed in prepupae is repeated before each developmental transition in the life cycle, including mid-embryogenesis and the larval molts. Whether the regulatory interactions between DHR3, betaFTZ-F1, E74A and E75A at these earlier stages are similar to those defined at the onset of metamorphosis, however, is unknown. In this study, we turn to embryonic development to address these two issues. We show that mid-embryonic expression of DHR3 and betaFTZ-F1 is part of a 20-hydroxyecdysone (20E)-triggered transcriptional cascade similar to that seen in mid-prepupae, directing maximal expression of E74A and E75A during late embryogenesis. In addition, DHR3 and betaFTZ-F1 exert overlapping developmental functions at the end of embryogenesis. Both genes are required for tracheal air filling, whereas DHR3 is required for ventral nerve cord condensation and betaFTZ-F1 is required for proper maturation of the cuticular denticles. Rescue experiments support these observations, indicating that DHR3 has essential functions independent from those of betaFTZ-F1. DHR3 and betaFTZ-F1 also contribute to overlapping transcriptional responses during embryogenesis. Taken together, these studies define the lethal phenotypes of DHR3 and betaFTZ-F1 mutants, and provide evidence for functional bifurcation in the 20E-responsive transcriptional cascade.
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Affiliation(s)
- Anne-Françoise Ruaud
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Room 2100, Salt Lake City, UT 84112-5330, USA
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41
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Patch K, Stewart SR, Welch A, Ward RE. A second-site noncomplementation screen for modifiers of Rho1 signaling during imaginal disc morphogenesis in Drosophila. PLoS One 2009; 4:e7574. [PMID: 19862331 PMCID: PMC2764050 DOI: 10.1371/journal.pone.0007574] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Accepted: 09/16/2009] [Indexed: 12/03/2022] Open
Abstract
Background Rho1 is a small GTPase of the Ras superfamily that serves as the central component in a highly conserved signaling pathway that regulates tissue morphogenesis during development in all animals. Since there is tremendous diversity in the upstream signals that can activate Rho1 as well as the effector molecules that carry out its functions, it is important to define relevant Rho1-interacting genes for each morphogenetic event regulated by this signaling pathway. Previous work from our lab and others has shown that Rho signaling is necessary for the morphogenesis of leg imaginal discs during metamorphosis in Drosophila, although a comprehensive identification of Rho1-interacting genes has not been attempted for this process. Methodology/Principal Findings We characterized an amorphic allele of Rho1 that displays a poorly penetrant dominant malformed leg phenotype and is capable of being strongly enhanced by Rho1-interacting heterozygous mutations. We then used this allele in a second-site noncomplementation screen with the Exelixis collection of molecularly defined deficiencies to identify Rho1-interacting genes necessary for leg morphogenesis. In a primary screen of 461 deficiencies collectively uncovering ∼50% of the Drosophila genome, we identified twelve intervals harboring Rho1-interacting genes. Through secondary screening we identified six Rho1-interacting genes including three that were previously identified (RhoGEF2, broad, and stubbloid), thereby validating the screen. In addition, we identified Cdc42, Rheb and Sc2 as novel Rho1-interacting genes involved in adult leg development. Conclusions/Significance This screen identified well-known and novel Rho1-interacting genes necessary for leg morphogenesis, thereby increasing our knowledge of this important signaling pathway. We additionally found that Rheb may have a unique function in leg morphogenesis that is independent of its regulation of Tor.
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Affiliation(s)
- Kistie Patch
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Shannon R. Stewart
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Aaron Welch
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Robert E. Ward
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
- * E-mail:
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Soin T, Swevers L, Mosallanejad H, Efrose R, Labropoulou V, Iatrou K, Smagghe G. Juvenile hormone analogs do not affect directly the activity of the ecdysteroid receptor complex in insect culture cell lines. JOURNAL OF INSECT PHYSIOLOGY 2008; 54:429-438. [PMID: 18093613 DOI: 10.1016/j.jinsphys.2007.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 10/30/2007] [Accepted: 11/08/2007] [Indexed: 05/25/2023]
Abstract
During insect development, ecdysteroids and juvenile hormones (JHs) interact to regulate larval growth, metamorphosis and reproduction but the molecular mechanisms by which both hormones influence each other's activity remain unknown. Because of their ease of use and straightforward genetic manipulation, insect cell lines often have been used to clarify the actions and interactions of hormones at the molecular level. Here we report on the use of two insect culture cell lines, Drosophila melanogaster S2 and Bombyx mori Bm5 cells, to investigate two molecular processes in which ecdysteroids and JH have been shown to interact: (1) direct modulation of the activity of the ecdysteroid receptor transcription complex and (2) interference at the level of induction of the primary gene E75. Our data do not support JH analogs (JHAs) acting through the above processes: 'antagonism' of ecdysteroid receptor activity by JHAs correlated with cytotoxicity and induction of E75 expression by JHAs was not demonstrated. However, we confirm previous studies in which it was observed that methoprene can partially reverse the growth inhibition by 20E in S2 cells (but not Bm5 cells). Therefore, the molecular mechanism by which both hormones influence each other's activity to regulate cell growth in S2 cells remains unknown.
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Affiliation(s)
- Thomas Soin
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent, Belgium.
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Sun Y, An S, Henrich VC, Sun X, Song Q. Proteomic Identification of PKC-Mediated Expression of 20E-Induced Protein in Drosophila melanogaster. J Proteome Res 2007; 6:4478-88. [DOI: 10.1021/pr0705183] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yaning Sun
- Division of Plant Sciences, 1-31 Agriculture Building, University of Missouri, Columbia, Missouri 65211, Center for Biotechnology, Genomics, and Health Research, 3703 MHRA Building, University of North Carolina, Greensboro, North Carolina 27402, and Laboratory of Experimental Gerontology, National Institute on Aging, 6200 Seaforth Street, Baltimore, Maryland 21224
| | - Shiheng An
- Division of Plant Sciences, 1-31 Agriculture Building, University of Missouri, Columbia, Missouri 65211, Center for Biotechnology, Genomics, and Health Research, 3703 MHRA Building, University of North Carolina, Greensboro, North Carolina 27402, and Laboratory of Experimental Gerontology, National Institute on Aging, 6200 Seaforth Street, Baltimore, Maryland 21224
| | - Vincent C. Henrich
- Division of Plant Sciences, 1-31 Agriculture Building, University of Missouri, Columbia, Missouri 65211, Center for Biotechnology, Genomics, and Health Research, 3703 MHRA Building, University of North Carolina, Greensboro, North Carolina 27402, and Laboratory of Experimental Gerontology, National Institute on Aging, 6200 Seaforth Street, Baltimore, Maryland 21224
| | - Xiaoping Sun
- Division of Plant Sciences, 1-31 Agriculture Building, University of Missouri, Columbia, Missouri 65211, Center for Biotechnology, Genomics, and Health Research, 3703 MHRA Building, University of North Carolina, Greensboro, North Carolina 27402, and Laboratory of Experimental Gerontology, National Institute on Aging, 6200 Seaforth Street, Baltimore, Maryland 21224
| | - Qisheng Song
- Division of Plant Sciences, 1-31 Agriculture Building, University of Missouri, Columbia, Missouri 65211, Center for Biotechnology, Genomics, and Health Research, 3703 MHRA Building, University of North Carolina, Greensboro, North Carolina 27402, and Laboratory of Experimental Gerontology, National Institute on Aging, 6200 Seaforth Street, Baltimore, Maryland 21224
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Sekimoto T, Iwami M, Sakurai S. 20-Hydroxyecdysone regulation of two isoforms of the Ets transcription factor E74 gene in programmed cell death in the silkworm anterior silk gland. INSECT MOLECULAR BIOLOGY 2007; 16:581-90. [PMID: 17894557 DOI: 10.1111/j.1365-2583.2007.00751.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Programmed cell death of larval-specific tissues in insects is under the control of 20-hydroxyecdysone (20E). The ecdysteroid-regulated early genes are conserved in the programmed cell death of anterior silk glands (ASGs) in Bombyx mori and salivary glands in Drosophila melanogaster. We identified and characterized two isoforms of the Ets transcription factor E74 gene in B. mori (BmE74). In ASGs of B. mori last instar larvae, the Bm74A mRNA level increased concomitantly with an increase in haemolymph ecdysteroid titre after gut purge. The optimal 20E concentration for stimulation of Bm74A in ASGs was 4 microM, a similar value to the peak haemolymph ecdysteroid concentration after gut purge. In contrast, BmE74B expression peaked on day 5 of the feeding period, after which it did not increase again. These findings suggest that the BmE74 isoforms play different roles in the regulation of programmed cell death in B. mori ASGs.
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Affiliation(s)
- T Sekimoto
- Division of Life Sciences, Graduate School of Science and Technology, Kanazawa University, Kakumamachi, Kanazawa, Japan
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Mitrofanov VG. Molecular-genetic mechanisms of the effect of developmental hormones in insects. Russ J Dev Biol 2007. [DOI: 10.1134/s1062360407050025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Beckstead RB, Lam G, Thummel CS. Specific transcriptional responses to juvenile hormone and ecdysone in Drosophila. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2007; 37:570-8. [PMID: 17517334 PMCID: PMC1976265 DOI: 10.1016/j.ibmb.2007.03.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 02/28/2007] [Indexed: 05/10/2023]
Abstract
Previous studies have shown that ecdysone (E), and its immediate downstream product 20-hydroxyecdysone (20E), can have different biological functions in insects, suggesting that E acts as a distinct hormone. Here, we use Drosophila larval organ culture in combination with microarray technology to identify genes that are transcriptionally regulated by E, but which show little or no response to 20E. These genes are coordinately expressed for a brief temporal interval at the onset of metamorphosis, suggesting that E acts together with 20E to direct puparium formation. We also show that E74B, pepck, and CG14949 can be induced by juvenile hormone III (JH III) in organ culture, and that CG14949 can be induced by JH independently of protein synthesis. In contrast, E74A and E75A show no response to JH in this system. These studies demonstrate that larval organ culture can be used to identify Drosophila genes that are regulated by hormones other than 20E, and provide a basis for studying crosstalk between multiple hormone signaling pathways.
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Affiliation(s)
| | | | - Carl S. Thummel
- *Corresponding author. Tel.: +801-581-2937; fax: +801-581-5374. E-mail address: (C.S. Thummel)
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Buszczak M, Spradling AC. The Drosophila P68 RNA helicase regulates transcriptional deactivation by promoting RNA release from chromatin. Genes Dev 2006; 20:977-89. [PMID: 16598038 PMCID: PMC1472305 DOI: 10.1101/gad.1396306] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 02/07/2006] [Indexed: 11/25/2022]
Abstract
Terminating a gene's activity requires that pre-existing transcripts be matured or destroyed and that the local chromatin structure be returned to an inactive configuration. Here we show that the Drosophila homolog of the mammalian P68 RNA helicase plays a novel role in RNA export and gene deactivation. p68 mutations phenotypically resemble mutations in small bristles (sbr), the Drosophila homolog of the human mRNA export factor NXF1. Full-length hsp70 mRNA accumulates in the nucleus near its sites of transcription following heat shock of p68 homozygotes, and hsp70 gene shutdown is delayed. Unstressed mutant larvae show similar defects in transcript accumulation and gene repression at diverse loci, and we find that p68 mutations are allelic to Lighten-up, a known suppressor of position effect variegation. Our observations reveal a strong connection between transcript clearance and gene repression. P68 may be needed to rapidly remove transcripts from a gene before its activity can be shut down and its chromatin reset to an inactive state.
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Affiliation(s)
- Michael Buszczak
- Howard Hughes Laboratories/Embryology Department, Carnegie Institution of Washington, Baltimore, Maryland 21218, USA
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Beckstead RB, Lam G, Thummel CS. The genomic response to 20-hydroxyecdysone at the onset of Drosophila metamorphosis. Genome Biol 2005; 6:R99. [PMID: 16356271 PMCID: PMC1414087 DOI: 10.1186/gb-2005-6-12-r99] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Revised: 08/05/2005] [Accepted: 10/20/2005] [Indexed: 05/05/2023] Open
Abstract
The genome-wide transcriptional response to 20-hydroxyecdisone at the onset of Drosophila metamorphosis, as well as its dependency on one of the ecdysone receptors is described. Background The steroid hormone 20-hydroxyecdysone (20E) triggers the major developmental transitions in Drosophila, including molting and metamorphosis, and provides a model system for defining the developmental and molecular mechanisms of steroid signaling. 20E acts via a heterodimer of two nuclear receptors, the ecdysone receptor (EcR) and Ultraspiracle, to directly regulate target gene transcription. Results Here we identify the genomic transcriptional response to 20E as well as those genes that are dependent on EcR for their proper regulation. We show that genes regulated by 20E, and dependent on EcR, account for many transcripts that are significantly up- or downregulated at puparium formation. We provide evidence that 20E and EcR participate in the regulation of genes involved in metabolism, stress, and immunity at the onset of metamorphosis. We also present an initial characterization of a 20E primary-response regulatory gene identified in this study, brain tumor (brat), showing that brat mutations lead to defects during metamorphosis and changes in the expression of key 20E-regulated genes. Conclusion This study provides a genome-wide basis for understanding how 20E and its receptor control metamorphosis, as well as a foundation for functional genomic analysis of key regulatory genes in the 20E signaling pathway during insect development.
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MESH Headings
- Animals
- Cells, Cultured
- DNA-Binding Proteins/genetics
- Drosophila Proteins/genetics
- Drosophila melanogaster/drug effects
- Drosophila melanogaster/genetics
- Drosophila melanogaster/growth & development
- Ecdysterone/pharmacology
- Gene Expression Regulation, Developmental/drug effects
- Genes, Insect/genetics
- Genes, Regulator/genetics
- Genome, Insect/drug effects
- Genome, Insect/genetics
- Immunity/genetics
- Larva/drug effects
- Larva/genetics
- Metamorphosis, Biological/drug effects
- Microarray Analysis
- Mutation/genetics
- Pupa/drug effects
- Pupa/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Steroid/genetics
- Reproducibility of Results
- Starvation/genetics
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Affiliation(s)
- Robert B Beckstead
- Department of Human Genetics, Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112-5331, USA
| | - Geanette Lam
- Department of Human Genetics, Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112-5331, USA
| | - Carl S Thummel
- Department of Human Genetics, Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112-5331, USA
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Colombani J, Bianchini L, Layalle S, Pondeville E, Dauphin-Villemant C, Antoniewski C, Carré C, Noselli S, Léopold P. Antagonistic actions of ecdysone and insulins determine final size in Drosophila. Science 2005; 310:667-70. [PMID: 16179433 DOI: 10.1126/science.1119432] [Citation(s) in RCA: 484] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
All animals coordinate growth and maturation to reach their final size and shape. In insects, insulin family molecules control growth and metabolism, whereas pulses of the steroid 20-hydroxyecdysone (20E) initiate major developmental transitions. We show that 20E signaling also negatively controls animal growth rates by impeding general insulin signaling involving localization of the transcription factor dFOXO and transcription of the translation inhibitor 4E-BP. We also demonstrate that the larval fat body, equivalent to the vertebrate liver, is a key relay element for ecdysone-dependent growth inhibition. Hence, ecdysone counteracts the growth-promoting action of insulins, thus forming a humoral regulatory loop that determines organismal size.
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Affiliation(s)
- Julien Colombani
- CNRS/University of Nice-Sophia Antipolis, UMR6543, Parc Valrose, 06108 Nice Cedex 2, France
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Caldwell PE, Walkiewicz M, Stern M. Ras activity in the Drosophila prothoracic gland regulates body size and developmental rate via ecdysone release. Curr Biol 2005; 15:1785-95. [PMID: 16182526 DOI: 10.1016/j.cub.2005.09.011] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Revised: 08/16/2005] [Accepted: 09/02/2005] [Indexed: 11/30/2022]
Abstract
BACKGROUND In Drosophila, each of the three larval instars ends with a molt, triggered by release of steroid molting hormone ecdysone from the prothoracic gland (PG). Because all growth occurs during the larval stages, final body size depends on both the larval growth rate and the duration of each larval stage, which in turn might be regulated by the timing of ecdysone release. RESULTS Here, we show that the expression of activated Ras, PI3 kinase (PI3K), or Raf specifically in the PG reduces body size, whereas activated Ras or PI3K, but not Raf, increases PG cell size. In contrast, expression of either dominant-negative (dn) Ras, Raf, or PI3K increases body size and prolongs the larval stages, leading to delayed pupariation, whereas expression of dn-PI3K, but not of dn-Raf or dn-Ras, reduces PG cell size. To test the possibility that altered ecdysone release is responsible for these phenotypes, we measured larval ecdysone levels indirectly, via the transcriptional activation of two ecdysone targets, E74A and E74B. We found that the activation of Ras within the PG induces precocious ecdysone release, whereas expression of either dn-PI3K or dn-Raf in the PG greatly attenuates the [ecdysone] increase that causes growth cessation and pupariation onset. CONCLUSIONS We conclude that Ras activity in the PG regulates body size and the duration of each larval stage by regulating ecdysone release. We also suggest that ecdysone release is regulated in two ways: a PI3K-dependent growth-promoting effect on PG cells, and a Raf-dependent step that may involve the transcriptional regulation of ecdysone biosynthetic genes.
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Affiliation(s)
- Philip E Caldwell
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251, USA.
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