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Poidevin M, Mazuras N, Bontonou G, Delamotte P, Denis B, Devilliers M, Akiki P, Petit D, de Luca L, Soulie P, Gillet C, Wicker-Thomas C, Montagne J. A fatty acid anabolic pathway in specialized-cells sustains a remote signal that controls egg activation in Drosophila. PLoS Genet 2024; 20:e1011186. [PMID: 38483976 DOI: 10.1371/journal.pgen.1011186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/26/2024] [Accepted: 02/14/2024] [Indexed: 03/27/2024] Open
Abstract
Egg activation, representing the critical oocyte-to-embryo transition, provokes meiosis completion, modification of the vitelline membrane to prevent polyspermy, and translation of maternally provided mRNAs. This transition is triggered by a calcium signal induced by spermatozoon fertilization in most animal species, but not in insects. In Drosophila melanogaster, mature oocytes remain arrested at metaphase-I of meiosis and the calcium-dependent activation occurs while the oocyte moves through the genital tract. Here, we discovered that the oenocytes of fruitfly females are required for egg activation. Oenocytes, cells specialized in lipid-metabolism, are located beneath the abdominal cuticle. In adult flies, they synthesize the fatty acids (FAs) that are the precursors of cuticular hydrocarbons (CHCs), including pheromones. The oenocyte-targeted knockdown of a set of FA-anabolic enzymes, involved in very-long-chain fatty acid (VLCFA) synthesis, leads to a defect in egg activation. Given that some but not all of the identified enzymes are required for CHC/pheromone biogenesis, this putative VLCFA-dependent remote control may rely on an as-yet unidentified CHC or may function in parallel to CHC biogenesis. Additionally, we discovered that the most posterior ventral oenocyte cluster is in close proximity to the uterus. Since oocytes dissected from females deficient in this FA-anabolic pathway can be activated in vitro, this regulatory loop likely operates upstream of the calcium trigger. To our knowledge, our findings provide the first evidence that a physiological extra-genital signal remotely controls egg activation. Moreover, our study highlights a potential metabolic link between pheromone-mediated partner recognition and egg activation.
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Affiliation(s)
- Mickael Poidevin
- Institut for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Sud, CEA, Gif-sur-Yvette, France
| | - Nicolas Mazuras
- Laboratoire Evolution, Génomes, Comportements, Ecologie (EGCE), CNRS, IRD, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Gwénaëlle Bontonou
- Laboratoire Evolution, Génomes, Comportements, Ecologie (EGCE), CNRS, IRD, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pierre Delamotte
- Institut for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Sud, CEA, Gif-sur-Yvette, France
| | - Béatrice Denis
- Laboratoire Evolution, Génomes, Comportements, Ecologie (EGCE), CNRS, IRD, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Maëlle Devilliers
- Institut for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Sud, CEA, Gif-sur-Yvette, France
| | - Perla Akiki
- Institut for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Sud, CEA, Gif-sur-Yvette, France
| | - Delphine Petit
- Institut for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Sud, CEA, Gif-sur-Yvette, France
| | - Laura de Luca
- Centre Médical Universitaire, Department of Cell Physiology and Metabolism, Geneva, Switzerland
| | - Priscilla Soulie
- Centre Médical Universitaire, Department of Cell Physiology and Metabolism, Geneva, Switzerland
| | - Cynthia Gillet
- Institut for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Sud, CEA, Gif-sur-Yvette, France
| | - Claude Wicker-Thomas
- Laboratoire Evolution, Génomes, Comportements, Ecologie (EGCE), CNRS, IRD, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Jacques Montagne
- Institut for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Sud, CEA, Gif-sur-Yvette, France
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Ji M, Vandenhole M, De Beer B, De Rouck S, Villacis-Perez E, Feyereisen R, Clark RM, Van Leeuwen T. A nuclear receptor HR96-related gene underlies large trans-driven differences in detoxification gene expression in a generalist herbivore. Nat Commun 2023; 14:4990. [PMID: 37591878 PMCID: PMC10435515 DOI: 10.1038/s41467-023-40778-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 08/09/2023] [Indexed: 08/19/2023] Open
Abstract
The role, magnitude, and molecular nature of trans-driven expression variation underlying the upregulation of detoxification genes in pesticide resistant arthropod populations has remained enigmatic. In this study, we performed expression quantitative trait locus (eQTL) mapping (n = 458) between a pesticide resistant and a susceptible strain of the generalist herbivore and crop pest Tetranychus urticae. We found that a single trans eQTL hotspot controlled large differences in the expression of a subset of genes in different detoxification gene families, as well as other genes associated with host plant use. As established by additional genetic approaches including RNAi gene knockdown, a duplicated gene with a nuclear hormone receptor HR96-related ligand-binding domain was identified as causal for the expression differences between strains. The presence of a large family of HR96-related genes in T. urticae may enable modular control of detoxification and host plant use genes, facilitating this species' known and rapid evolution to diverse pesticides and host plants.
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Affiliation(s)
- Meiyuan Ji
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Marilou Vandenhole
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Berdien De Beer
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sander De Rouck
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Ernesto Villacis-Perez
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - René Feyereisen
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Richard M Clark
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA.
- Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, UT, USA.
| | - Thomas Van Leeuwen
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
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The nuclear receptor Hr46/Hr3 is required in the blood brain barrier of mature males for courtship. PLoS Genet 2022; 18:e1009519. [PMID: 35077443 PMCID: PMC8815886 DOI: 10.1371/journal.pgen.1009519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 02/04/2022] [Accepted: 12/24/2021] [Indexed: 11/19/2022] Open
Abstract
The blood brain barrier (BBB) forms a stringent barrier that protects the brain from components in the circulation that could interfere with neuronal function. At the same time, the BBB enables selective transport of critical nutrients and other chemicals to the brain. Beyond these functions, another recently recognized function is even less characterized, specifically the role of the BBB in modulating behavior by affecting neuronal function in a sex-dependent manner. Notably, signaling in the adult Drosophila BBB is required for normal male courtship behavior. Courtship regulation also relies on male-specific molecules in the BBB. Our previous studies have demonstrated that adult feminization of these cells in males significantly lowered courtship. Here, we conducted microarray analysis of BBB cells isolated from males and females. Findings revealed that these cells contain male- and female-enriched transcripts, respectively. Among these transcripts, nuclear receptor Hr46/Hr3 was identified as a male-enriched BBB transcript. Hr46/Hr3 is best known for its essential roles in the ecdysone response during development and metamorphosis. In this study, we demonstrate that Hr46/Hr3 is specifically required in the BBB cells for courtship behavior in mature males. The protein is localized in the nuclei of sub-perineurial glial cells (SPG), indicating that it might act as a transcriptional regulator. These data provide a catalogue of sexually dimorphic BBB transcripts and demonstrate a physiological adult role for the nuclear receptor Hr46/Hr3 in the regulation of male courtship, a novel function that is independent of its developmental role.
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Devilliers M, Garrido D, Poidevin M, Rubin T, Le Rouzic A, Montagne J. Differential metabolic sensitivity of insulin-like-response- and TORC1-dependent overgrowth in Drosophila fat cells. Genetics 2021; 217:1-12. [PMID: 33683355 DOI: 10.1093/genetics/iyaa010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/02/2020] [Indexed: 12/19/2022] Open
Abstract
Glycolysis and fatty acid (FA) synthesis directs the production of energy-carrying molecules and building blocks necessary to support cell growth, although the absolute requirement of these metabolic pathways must be deeply investigated. Here, we used Drosophila genetics and focus on the TOR (Target of Rapamycin) signaling network that controls cell growth and homeostasis. In mammals, mTOR (mechanistic-TOR) is present in two distinct complexes, mTORC1 and mTORC2; the former directly responds to amino acids and energy levels, whereas the latter sustains insulin-like-peptide (Ilp) response. The TORC1 and Ilp signaling branches can be independently modulated in most Drosophila tissues. We show that TORC1 and Ilp-dependent overgrowth can operate independently in fat cells and that ubiquitous over-activation of TORC1 or Ilp signaling affects basal metabolism, supporting the use of Drosophila as a powerful model to study the link between growth and metabolism. We show that cell-autonomous restriction of glycolysis or FA synthesis in fat cells retrains overgrowth dependent on Ilp signaling but not TORC1 signaling. Additionally, the mutation of FASN (Fatty acid synthase) results in a drop in TORC1 but not Ilp signaling, whereas, at the cell-autonomous level, this mutation affects none of these signals in fat cells. These findings thus reveal differential metabolic sensitivity of TORC1- and Ilp-dependent growth and suggest that cell-autonomous metabolic defects might elicit local compensatory pathways. Conversely, enzyme knockdown in the whole organism results in animal death. Importantly, our study weakens the use of single inhibitors to fight mTOR-related diseases and strengthens the use of drug combination and selective tissue-targeting.
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Affiliation(s)
- Maelle Devilliers
- Institute for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Saclay, CEA, F-91190 Gif-sur-Yvette, France
| | - Damien Garrido
- Institute for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Saclay, CEA, F-91190 Gif-sur-Yvette, France
| | - Mickael Poidevin
- Institute for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Saclay, CEA, F-91190 Gif-sur-Yvette, France
| | - Thomas Rubin
- Institute for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Saclay, CEA, F-91190 Gif-sur-Yvette, France
| | - Arnaud Le Rouzic
- Laboratoire Evolution, Génomes, Comportement et Ecologie, CNRS, Université Paris-Saclay, UMR 9191, F-91190 Gif-sur-Yvette, France
| | - Jacques Montagne
- Institute for Integrative Biology of the Cell (I2BC), CNRS, Université Paris-Saclay, CEA, F-91190 Gif-sur-Yvette, France
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Lin X, Smagghe G. Roles of the insulin signaling pathway in insect development and organ growth. Peptides 2019; 122:169923. [PMID: 29458057 DOI: 10.1016/j.peptides.2018.02.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/13/2018] [Accepted: 02/13/2018] [Indexed: 12/16/2022]
Abstract
Organismal development is a complex process as it requires coordination of many aspects to grow into fit individuals, such as the control of body size and organ growth. Therefore, the mechanisms of precise control of growth are essential for ensuring the growth of organisms at a correct body size and proper organ proportions during development. The control of the growth rate and the duration of growth (or the cessation of growth) are required in size control. The insulin signaling pathway and the elements involved are essential in the control of growth. On the other hand, the ecdysteroid molting hormone determines the duration of growth. The secretion of these hormones is controlled by environmental factors such as nutrition. Moreover, the target of rapamycin (TOR) pathway is considered as a nutrient sensing pathway. Important cross-talks have been shown to exist among these pathways. In this review, we outline the control of body and organ growth by the insulin/TOR signaling pathway, and also the interaction between nutrition via insulin/TOR signaling and ecdysteroids at the coordination of organismal development and organ growth in insects, mainly focusing on the well-studied fruit fly Drosophila melanogaster.
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Affiliation(s)
- Xianyu Lin
- Department of Crop Protection, Ghent University, 9000 Ghent, Belgium
| | - Guy Smagghe
- Department of Crop Protection, Ghent University, 9000 Ghent, Belgium.
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Snoeck S, Kurlovs AH, Bajda S, Feyereisen R, Greenhalgh R, Villacis-Perez E, Kosterlitz O, Dermauw W, Clark RM, Van Leeuwen T. High-resolution QTL mapping in Tetranychus urticae reveals acaricide-specific responses and common target-site resistance after selection by different METI-I acaricides. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 110:19-33. [PMID: 31022513 DOI: 10.1016/j.ibmb.2019.04.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/08/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
Arthropod herbivores cause dramatic crop losses, and frequent pesticide use has led to widespread resistance in numerous species. One such species, the two-spotted spider mite, Tetranychus urticae, is an extreme generalist herbivore and a major worldwide crop pest with a history of rapidly developing resistance to acaricides. Mitochondrial Electron Transport Inhibitors of complex I (METI-Is) have been used extensively in the last 25 years to control T. urticae around the globe, and widespread resistance to each has been documented. METI-I resistance mechanisms in T. urticae are likely complex, as increased metabolism by cytochrome P450 monooxygenases as well as a target-site mutation have been linked with resistance. To identify loci underlying resistance to the METI-I acaricides fenpyroximate, pyridaben and tebufenpyrad without prior hypotheses, we crossed a highly METI-I-resistant strain of T. urticae to a susceptible one, propagated many replicated populations over multiple generations with and without selection by each compound, and performed bulked segregant analysis genetic mapping. Our results showed that while the known H92R target-site mutation was associated with resistance to each compound, a genomic region that included cytochrome P450-reductase (CPR) was associated with resistance to pyridaben and tebufenpyrad. Within CPR, a single nonsynonymous variant distinguished the resistant strain from the sensitive one. Furthermore, a genomic region linked with tebufenpyrad resistance harbored a non-canonical member of the nuclear hormone receptor 96 (NHR96) gene family. This NHR96 gene does not encode a DNA-binding domain (DBD), an uncommon feature in arthropods, and belongs to an expanded family of 47 NHR96 proteins lacking DBDs in T. urticae. Our findings suggest that although cross-resistance to METI-Is involves known detoxification pathways, structural differences in METI-I acaricides have also resulted in resistance mechanisms that are compound-specific.
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Affiliation(s)
- Simon Snoeck
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium.
| | - Andre H Kurlovs
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium; School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA.
| | - Sabina Bajda
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium.
| | - René Feyereisen
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium; Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej, Copenhagen, Denmark.
| | - Robert Greenhalgh
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA.
| | - Ernesto Villacis-Perez
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (UvA), Science Park 904, 1908 XH, Amsterdam, the Netherlands.
| | - Olivia Kosterlitz
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA; Present address: Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA, 98195, USA.
| | - Wannes Dermauw
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium.
| | - Richard M Clark
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA; Center for Cell and Genome Science, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112, USA.
| | - Thomas Van Leeuwen
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium; Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (UvA), Science Park 904, 1908 XH, Amsterdam, the Netherlands.
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A Drosophila genetic screen for suppressors of S6kinase-dependent growth identifies the F-box subunit Archipelago/FBXW7. Mol Genet Genomics 2019; 294:573-582. [PMID: 30656413 DOI: 10.1007/s00438-018-01529-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 12/26/2018] [Indexed: 12/12/2022]
Abstract
This study was designed to identify novel negative regulators of the Drosophila S6kinase (dS6K). S6K is a downstream effector of the growth-regulatory complex mTORC1 (mechanistic-Target-of-Rapamycin complex 1). Nutrients activate mTORC1, which in turn induces the phosphorylation of S6K to promote cell growth, whereas fasting represses mTORC1 activity. Here, we screened 11,000 RNA-interfering (RNAi) lines and retained those that enhanced a dS6K-dependent growth phenotype. Since RNAi induces gene knockdown, enhanced tissue growth supports the idea that the targeted gene acts as a growth suppressor. To validate the resulting candidate genes, we monitored dS6K phosphorylation and protein levels in double-stranded RNAi-treated S2 cells. We identified novel dS6K negative regulators, including gene products implicated in basal cellular functions, suggesting that feedback inputs modulate mTORC1/dS6K signaling. We also identified Archipelago (Ago), the Drosophila homologue of FBXW7, which is an E3-ubiquitin-ligase subunit that loads ubiquitin units onto target substrates for proteasome-mediated degradation. Despite a previous report showing an interaction between Ago/FBXW7 and dS6K in a yeast two-hybrid assay and the presence of an Ago/FBXW7-consensus motif in the dS6K polypeptide, we could not see a direct interaction in immunoprecipitation assay. Nevertheless, we observed that loss-of-ago/fbxw7 in larvae resulted in an increase in dS6K protein levels, but no change in the levels of phosphorylated dS6K or dS6K transcripts, suggesting that Ago/FBXW7 indirectly controls dS6K translation or stability. Through the identification of novel negative regulators of the downstream target, dS6K, our study may help deciphering the underlying mechanisms driving deregulations of mTORC1, which underlies several human diseases.
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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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Eichner C, Dalvin S, Skern-Mauritzen R, Malde K, Kongshaug H, Nilsen F. Characterization of a novel RXR receptor in the salmon louse (Lepeophtheirus salmonis, Copepoda) regulating growth and female reproduction. BMC Genomics 2015; 16:81. [PMID: 25765704 PMCID: PMC4333900 DOI: 10.1186/s12864-015-1277-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/22/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Nuclear receptors have crucial roles in all metazoan animals as regulators of gene transcription. A wide range of studies have elucidated molecular and biological significance of nuclear receptors but there are still a large number of animals where the knowledge is very limited. In the present study we have identified an RXR type of nuclear receptor in the salmon louse (Lepeophtheirus salmonis) (i.e. LsRXR). RXR is one of the two partners of the Ecdysteroid receptor in arthropods, the receptor for the main molting hormone 20-hydroxyecdysone (E20) with a wide array of effects in arthropods. RESULTS Five different LsRXR transcripts were identified by RACE showing large differences in domain structure. The largest isoforms contained complete DNA binding domain (DBD) and ligand binding domain (LBD), whereas some variants had incomplete or no DBD. LsRXR is transcribed in several tissues in the salmon louse including ovary, subcuticular tissue, intestine and glands. By using Q-PCR it is evident that the LsRXR mRNA levels vary throughout the L. salmonis life cycle. We also show that the truncated LsRXR transcript comprise about 50% in all examined samples. We used RNAi to knock-down the transcription in adult reproducing female lice. This resulted in close to zero viable offspring. We also assessed the LsRXR RNAi effects using a L. salmonis microarray and saw significant effects on transcription in the female lice. Transcription of the major yolk proteins was strongly reduced by knock-down of LsRXR. Genes involved in lipid metabolism and transport were also down regulated. Furthermore, different types of growth processes were up regulated and many cuticle proteins were present in this group. CONCLUSIONS The present study demonstrates the significance of LsRXR in adult female L. salmonis and discusses the functional aspects in relation to other arthropods. LsRXR has a unique structure that should be elucidated in the future.
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Affiliation(s)
- Christiane Eichner
- Department of Biology, Sea Lice Research Centre, University of Bergen, Bergen, Norway.
| | - Sussie Dalvin
- Department of Biology, Sea Lice Research Centre, University of Bergen, Bergen, Norway. .,Institute of Marine Research, Bergen, Norway.
| | | | - Ketil Malde
- Institute of Marine Research, Bergen, Norway.
| | - Heidi Kongshaug
- Department of Biology, Sea Lice Research Centre, University of Bergen, Bergen, Norway.
| | - Frank Nilsen
- Department of Biology, Sea Lice Research Centre, University of Bergen, Bergen, Norway.
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Parvy JP, Wang P, Garrido D, Maria A, Blais C, Poidevin M, Montagne J. Forward and feedback regulation of cyclic steroid production in Drosophila melanogaster. Development 2014; 141:3955-65. [PMID: 25252945 DOI: 10.1242/dev.102020] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In most animals, steroid hormones are crucial regulators of physiology and developmental life transitions. Steroid synthesis depends on extrinsic parameters and autoregulatory processes to fine-tune the dynamics of hormone production. In Drosophila, transient increases of the steroid prohormone ecdysone, produced at each larval stage, are necessary to trigger moulting and metamorphosis. Binding of the active ecdysone (20-hydroxyecdysone) to its receptor (EcR) is followed by the sequential expression of the nuclear receptors E75, DHR3 and βFtz-f1, representing a model for steroid hormone signalling. Here, we have combined genetic and imaging approaches to investigate the precise role of this signalling cascade within theprothoracic gland (PG), where ecdysone synthesis takes place. We show that these receptors operate through an apparent unconventional hierarchy in the PG to control ecdysone biosynthesis. At metamorphosis onset, DHR3 emerges as the downstream component that represses steroidogenic enzymes and requires an early effect of EcR for this repression. To avoid premature repression of steroidogenesis, E75 counteracts DHR3 activity, whereas EcR and βFtz-f1 act early in development through a forward process to moderate DHR3 levels. Our findings suggest that within the steroidogenic tissue, a given 20-hydroxyecdysone peak induces autoregulatory processes to sharpen ecdysone production and to confer competence for ecdysteroid biosynthesis at the next developmental phase, providing novel insights into steroid hormone kinetics.
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Affiliation(s)
- Jean-Philippe Parvy
- CGM, UPR 3404, CNRS, Gif sur Yvette 91190, France Université Pierre et Marie Curie, Paris 75005, France
| | - Peng Wang
- CGM, UPR 3404, CNRS, Gif sur Yvette 91190, France Université Paris-Sud 11, Orsay 91400, France
| | - Damien Garrido
- CGM, UPR 3404, CNRS, Gif sur Yvette 91190, France Université Paris-Sud 11, Orsay 91400, France
| | | | | | - Mickael Poidevin
- CGM, UPR 3404, CNRS, Gif sur Yvette 91190, France Université Paris-Sud 11, Orsay 91400, France
| | - Jacques Montagne
- CGM, UPR 3404, CNRS, Gif sur Yvette 91190, France Université Paris-Sud 11, Orsay 91400, France
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Koyama T, Mendes CC, Mirth CK. Mechanisms regulating nutrition-dependent developmental plasticity through organ-specific effects in insects. Front Physiol 2013; 4:263. [PMID: 24133450 PMCID: PMC3783933 DOI: 10.3389/fphys.2013.00263] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 09/06/2013] [Indexed: 12/25/2022] Open
Abstract
Nutrition, via the insulin/insulin-like growth factor (IIS)/Target of Rapamycin (TOR) signaling pathway, can provide a strong molding force for determining animal size and shape. For instance, nutrition induces a disproportionate increase in the size of male horns in dung and rhinoceros beetles, or mandibles in staghorn or horned flour beetles, relative to body size. In these species, well-fed male larvae produce adults with greatly enlarged horns or mandibles, whereas males that are starved or poorly fed as larvae bear much more modest appendages. Changes in IIS/TOR signaling plays a key role in appendage development by regulating growth in the horn and mandible primordia. In contrast, changes in the IIS/TOR pathway produce minimal effects on the size of other adult structures, such as the male genitalia in fruit flies and dung beetles. The horn, mandible and genitalia illustrate that although all tissues are exposed to the same hormonal environment within the larval body, the extent to which insulin can induce growth is organ specific. In addition, the IIS/TOR pathway affects body size and shape by controlling production of metamorphic hormones important for regulating developmental timing, like the steroid molting hormone ecdysone and sesquiterpenoid hormone juvenile hormone. In this review, we discuss recent results from Drosophila and other insects that highlight mechanisms allowing tissues to differ in their sensitivity to IIS/TOR and the potential consequences of these differences on body size and shape.
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Affiliation(s)
- Takashi Koyama
- Development, Evolution and the Environment Laboratory, Instituto Gulbenkian de Ciência Oeiras, Portugal
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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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Kim H, Lee JM, Lee G, Bhin J, Oh SK, Kim K, Pyo KE, Lee JS, Yim HY, Kim KI, Hwang D, Chung J, Baek SH. DNA damage-induced RORα is crucial for p53 stabilization and increased apoptosis. Mol Cell 2012; 44:797-810. [PMID: 22152482 DOI: 10.1016/j.molcel.2011.09.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 07/18/2011] [Accepted: 09/10/2011] [Indexed: 10/14/2022]
Abstract
A critical component of the DNA damage response is the p53 tumor suppressor, and aberrant p53 function leads to uncontrolled cell proliferation and malignancy. Several molecules have been shown to regulate p53 stability; however, genome-wide systemic approaches for determining the affected, specific downstream target genes have not been extensively studied. Here, we first identified an orphan nuclear receptor, RORα, as a direct target gene of p53, which contains functional p53 response elements. The functional consequences of DNA damage-induced RORα are to stabilize p53 and activate p53 transcription in a HAUSP/Usp7-dependent manner. Interestingly, microarray analysis revealed that RORα-mediated p53 stabilization leads to the activation of a subset of p53 target genes that are specifically involved in apoptosis. We further confirmed that RORα enhances p53-dependent, in vivo apoptotic function in the Drosophila model system. Together, we determined that RORα is a p53 regulator that exerts its role in increased apoptosis via p53.
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Affiliation(s)
- Hyunkyung Kim
- Department of Biological Sciences, Creative Research Initiative Center for Chromatin Dynamics, Seoul National University, Seoul 151-742, South Korea
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Zhang YL, Zhang SZ, Kulye M, Wu SR, Yu NT, Wang JH, Zeng HM, Liu ZX. Silencing of molt-regulating transcription factor gene, CiHR3, affects growth and development of sugarcane stem borer, Chilo infuscatellus. JOURNAL OF INSECT SCIENCE (ONLINE) 2012; 12:91. [PMID: 23427912 PMCID: PMC3596932 DOI: 10.1673/031.012.9101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
RNA interference (RNAi) is a technology for conducting functional genomic studies and a potential tool for crop protection against insect pests. Development of reliable methods for production and delivery of double-stranded RNA (dsRNA) is the major challenge for efficient pest control. In this study, Chilo infuscatellus Snellen (Crambidae: Lepidoptera) was fed with CiHR3 dsRNA expressed in bacteria or synthesized in vitro. The dsRNA ingested by C. infuscatellus successfully triggered silencing of the molt-regulating transcription factor CiHR3, an important gene for insect growth and development, and caused significant abnormalities and weight loss in insects within seven days of treatment. This study is an ideal example of feeding-based RNAi mediated by dsRNA expressed in bacteria or synthesized in vitro. The results also suggested that feeding-based RNA interference is a potential method for the management of C. infuscatellus.
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Affiliation(s)
- Yu-liang Zhang
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, Hainan 571101, P. R. China
| | - Shu-zhen Zhang
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, Hainan 571101, P. R. China
| | - Mahesh Kulye
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China
| | - Su-ran Wu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, Hainan 571101, P. R. China
| | - Nai-tong Yu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, Hainan 571101, P. R. China
| | - Jian-hua Wang
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, Hainan 571101, P. R. China
| | - Hong-mei Zeng
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China
- Authors contributed equally to this paper
| | - Zhi-xin Liu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Science, Haikou, Hainan 571101, P. R. China
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Yamanaka N, O'Connor MB. Nitric oxide directly regulates gene expression during Drosophila development: need some gas to drive into metamorphosis? Genes Dev 2011; 25:1459-63. [PMID: 21764850 DOI: 10.1101/gad.2080411] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nitric oxide (NO) is an important second messenger involved in numerous biological processes, but how it regulates gene expression is not well understood. In this issue of Genes & Development, Cáceres and colleagues (pp. 1476-1485) report a critical requirement of NO as a direct regulator of gene expression through its binding to a heme-containing nuclear receptor in Drosophila. This may be an anciently evolved mechanism to coordinate behavior and metabolism during animal development.
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Affiliation(s)
- Naoki Yamanaka
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, USA
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