Ecdysone signaling induces two phases of cell cycle exit in Drosophila cells
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE77562 | GEO | 2017/02/10
SECONDARY ACCESSION(S): PRJNA310853
REPOSITORIES: GEO
Similar Datasets
Project description:Steroid hormones control various cellular activities in a context-dependent manner. For example, ecdysone, which acts through a type II nuclear receptor, has seemingly opposite effects in Drosophila wing precursors, promoting proliferation during larval stages, and triggering proliferation arrest at pupariation. We find that wing precursors proliferate normally in the complete absence of the ecdysone receptor (EcR), whether ecdysone is present or not, suggesting that ecdysone overrides a default anti-proliferative activity of the receptor. By contrast, termination of proliferation by high concentration of 20E at the end of larval life requires ligand-induced transcriptional activation by the receptor. The switch from one mode of regulation to the other is determined by ligand level, as measured with a calibrated EcR transcriptional reporter and ex vivo proliferation assays. Accordingly, RNA Seq analysis uncovers distinct transcriptional responses to different doses of ecdysone. Some genes are only activated at high doses (high threshold targets) and likely to comprise genes that stop proliferation at pupariation, when ecdysone titres are high. We find that other target genes respond to all physiological concentrations of ecdysone. Some of these genes are known to promote proliferation and could therefore contribute to the pro-proliferation activity of low-level ecdysone. Finally, we show mathematically and with synthetic reporters that relatively simple combinations of regulatory elements can recapitulate the behaviour of both types of target genes.
2023-08-24 | GSE236166 | GEO
Project description:Coupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. The metamorphosis of the fruit fly represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. However, the mechanisms that coordinate development and immune cell activity in the transition from larva to adult in Drosophila remain to elucidate. The steroid hormone ecdysone is known to act as a key coordinator of metamorphosis. This hormone activates a nuclear receptor, the Ecdysone Receptor (EcR), which acts as a heterodimer with its partner Ultraspiracle (USP). Together, they activate the transcription of primary response genes, which in turn activate the transcription of a battery of late response genes. We have revealed that regulation of macrophage-like cells (hemocytes) by the steroid hormone ecdysone is essential for an effective innate immune response over metamorphosis. We have shown that in response to ecdysone signalling, hemocytes rapidly up regulate actin dynamics, motility and phagocytosis of apoptotic corpses, and acquire the ability to chemotax to damaged epithelia. Most importantly, individuals lacking ecdysone-activated hemocytes are defective in bacterial phagocytosis and are fatally susceptible to infection by bacteria ingested at larval stages, despite the normal systemic production of antimicrobial peptides. This decrease in survival is comparable to the one observed in pupae lacking immune cells altogether, indicating that ecdysone-regulation is essential to hemocyte immune functions and survival after infection. To better understand the ecdysone regulation of hemocyte activities, we have performed gene expression analysis. In order to identify the genes which expression change at the onset of metamorphosis, we have sorted hemocytes from 3rd instar larvae and from young prepupae and compared their gene expression. Moreover, and in order to identify which genes are regulated by the ecdysone signalling, we have used individuals expressing a dominant negative form of the Ecdysone Receptor specifically in their hemocytes. We have sorted hemocytes from 3rd instar and young prepupae of this genotype to compare their gene expression to the gene expression in larvae and prepupae from the control individuals. Hemocytes were isolated by FACS from selected 3rd instar larvae (at the late feeding stage) and prepupae (from 1h to 2h after puparium formation - APF) corresponding to two different genotypes: individuals w;HmlDeltaGal4, UAS-GFP/+ that express GFP specifically in hemocytes (genotype control), and individuals w;HmlDeltaGal4; UAS-GFP/UAS-EcRB1DN W650A which hemocytes express an Ecdysone Receptor Dominant Negative construct in addition to the GFP (EcRDN). For each of the four conditions we performed three biological replicates.
2013-10-25 | E-GEOD-49326 | biostudies-arrayexpress
Project description:Coupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. The metamorphosis of the fruit fly represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. However, the mechanisms that coordinate development and immune cell activity in the transition from larva to adult in Drosophila remain to elucidate. The steroid hormone ecdysone is known to act as a key coordinator of metamorphosis. This hormone activates a nuclear receptor, the Ecdysone Receptor (EcR), which acts as a heterodimer with its partner Ultraspiracle (USP). Together, they activate the transcription of primary response genes, which in turn activate the transcription of a battery of late response genes. We have revealed that regulation of macrophage-like cells (hemocytes) by the steroid hormone ecdysone is essential for an effective innate immune response over metamorphosis. We have shown that in response to ecdysone signalling, hemocytes rapidly up regulate actin dynamics, motility and phagocytosis of apoptotic corpses, and acquire the ability to chemotax to damaged epithelia. Most importantly, individuals lacking ecdysone-activated hemocytes are defective in bacterial phagocytosis and are fatally susceptible to infection by bacteria ingested at larval stages, despite the normal systemic production of antimicrobial peptides. This decrease in survival is comparable to the one observed in pupae lacking immune cells altogether, indicating that ecdysone-regulation is essential to hemocyte immune functions and survival after infection. To better understand the ecdysone regulation of hemocyte activities, we have performed gene expression analysis. In order to identify the genes which expression change at the onset of metamorphosis, we have sorted hemocytes from 3rd instar larvae and from young prepupae and compared their gene expression. Moreover, and in order to identify which genes are regulated by the ecdysone signalling, we have used individuals expressing a dominant negative form of the Ecdysone Receptor specifically in their hemocytes. We have sorted hemocytes from 3rd instar and young prepupae of this genotype to compare their gene expression to the gene expression in larvae and prepupae from the control individuals.
2013-10-25 | GSE49326 | GEO
Project description: Not available
| S-EPMC5155522 | biostudies-literature
Project description:Ecdysone signaling has long been studied as a paradigm for how hormones can synchronize development events in tissues throughout the animal. At the genetic level, ecdysone acts through its receptor, EcR, which has been classically thought to act at a relatively small number of canonical, ecdysone-responsive genes which then go on to activate the effectors of cellular processes. However, in spite of the decades of work studying EcR, the understanding of how EcR promotes changes in gene expression genome-wide in vivo remains incomplete. To examine EcR’s role in promoting changes in gene expression, we use a tissue-specific GAL4 driver to knockdown EcR throughout wing development and perform RNAseq on both WT wings and EcR-RNAi wings at -6h after puparium formation (APF) and +6hAPF. We find that EcR is required to promote thousands of gene expression changes genome-wide. To determine whether EcR is directly effecting these changes, we perform CUT&RUN in wings to identify EcR binding sites genome-wide. We find that EcR directly binds thousands of sites genome-wide, including many genes important for wing development. Collectively, these data suggest that EcR does not only act the top of a signaling cascade, but, instead, directly effects the response to ecdysone at multiple levels.
2019-04-24 | GSE124254 | GEO
Project description:We used the DamID method to systematically identify the binding sites of Ecdysone Receptor and its heterodimeric partner USP across the whole genome in Drosophila Kc cells. We find that the EcR sites are a subset of the USP sites and that only a proportion are ecdysone regulated from an accompanying ecdysone profiling study. The role of EcR/USP in the ecdysone network appears to be coordinated by the recruitment of many transcription factors as well as signaling molecules. Keywords: DamID, chromatin profiling, DNA microarray
2008-05-01 | GSE9156 | GEO
Project description:Global quantitative proteomics reveals novel factors in the ecdysone signaling pathway in Drosophila melanogaster.
2015-01-23 | PXD001455 | Pride
Project description:Background: We studied the chromatin accessibility landscsape in wings during butterfly metamorphosis, and investigate which transcription factors might be driving changes in accessibility Methods: We sequencing the Junonia coenia genome, and we studied chromatin accessibility using ATAC seq in multiple stages of wing development in both forewings and hindwings. For sites showing a large change in accessibility, we investigate which motifs are enriched, and correlate this with changes in gene expression of associated transcription factors. We confirm promising candidates with ChIP-seq Results: We find a highly dynamic landscape, with multiple peaks showing a double increase in accessibility throughout development. We show that transcription factor spineless, but not ecdysone receptor, is highly predictive of opening sites Conclusions: This work provides a characterization of the chromatin dynamics of insect wing metamorphosis, identifies novel candidate chromatin remodeling factors in insects, and provides the first genome assembly of the model butterfly Junonia coenia, with gene and cis-regulatory element annotations
2019-04-30 | GSE121734 | GEO
Project description:Background: We studied the chromatin accessibility landscsape in wings during butterfly metamorphosis, and investigate which transcription factors might be driving changes in accessibility Methods: We sequencing the Junonia coenia genome, and we studied chromatin accessibility using ATAC seq in multiple stages of wing development in both forewings and hindwings. For sites showing a large change in accessibility, we investigate which motifs are enriched, and correlate this with changes in gene expression of associated transcription factors. We confirm promising candidates with ChIP-seq Results: We find a highly dynamic landscape, with multiple peaks showing a double increase in accessibility throughout development. We show that transcription factor spineless, but not ecdysone receptor, is highly predictive of opening sites Conclusions: This work provides a characterization of the chromatin dynamics of insect wing metamorphosis, identifies novel candidate chromatin remodeling factors in insects, and provides the first genome assembly of the model butterfly Junonia coenia, with gene and cis-regulatory element annotations
2019-05-07 | GSE121542 | GEO
Project description:Background: We studied the chromatin accessibility landscsape in wings during butterfly metamorphosis, and investigate which transcription factors might be driving changes in accessibility Methods: We sequencing the Junonia coenia genome, and we studied chromatin accessibility using ATAC seq in multiple stages of wing development in both forewings and hindwings. For sites showing a large change in accessibility, we investigate which motifs are enriched, and correlate this with changes in gene expression of associated transcription factors. We confirm promising candidates with ChIP-seq Results: We find a highly dynamic landscape, with multiple peaks showing a double increase in accessibility throughout development. We show that transcription factor spineless, but not ecdysone receptor, is highly predictive of opening sites Conclusions: This work provides a characterization of the chromatin dynamics of insect wing metamorphosis, identifies novel candidate chromatin remodeling factors in insects, and provides the first genome assembly of the model butterfly Junonia coenia, with gene and cis-regulatory element annotations
2019-04-30 | GSE121541 | GEO