Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA196913 | ENA |
REPOSITORIES: ENA
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Project description:Juvenile hormone (JH) and 20-hydroxy-ecdysone (20E) are highly versatile hormones, coordinating development, growth, and reproduction in insects. Pulses of 20E provide key signals for initiating developmental and physiological transitions, while JH promotes or inhibits these signals in a stage-specific manner. Previous evidence suggests that JH and 20E might modulate innate immunity, but whether and how these hormones interact to regulate the immune response remains unclear. Here we show that JH and 20E have antagonistic effects on the expression of antimicrobial peptides (AMPs) in Drosophila melanogaster. In S2* cells challenged with bacterial peptidoglycans, 20E induces promoter activity and expression of AMPs in a dose-dependent manner, while JH III and its synthetic analogs (JHa) methoprene and pyriproxyfen abolish this 20E-dependent response. Using microarrays and GFP reporter gene assays in adult flies, we confirm that JH is a hormonal immuno-suppressor in vivo. When silencing both partners of the ecdysone receptor (EcR ) / ultraspiracle (USP) heterodimer with RNAi in S2* cells, 20E fails to activate Diptericin (Dpt) expression, suggesting that 20E regulates expression of this gene through EcR / USP signaling. In contrast, silencing methoprene-tolerant (MET), a candidate JH receptor, does not impair the immuno-suppressive action of JH III and JHa, indicating that in this context MET does not function as a JH receptor. Our results suggest that the balance of 20E and JH is a major determinant of immune homeostasis in insects. Keywords: Topical hormone treatment of whole flies
2007-12-31 | GSE9001 | GEO
Project description:Juvenile hormone (JH) and 20-hydroxy-ecdysone (20E) are highly versatile hormones, coordinating development, growth, and reproduction in insects. Pulses of 20E provide key signals for initiating developmental and physiological transitions, while JH promotes or inhibits these signals in a stage-specific manner. Previous evidence suggests that JH and 20E might modulate innate immunity, but whether and how these hormones interact to regulate the immune response remains unclear. Here we show that JH and 20E have antagonistic effects on the expression of antimicrobial peptides (AMPs) in Drosophila melanogaster. In S2* cells challenged with bacterial peptidoglycans, 20E induces promoter activity and expression of AMPs in a dose-dependent manner, while JH III and its synthetic analogs (JHa) methoprene and pyriproxyfen abolish this 20E-dependent response. Using microarrays and GFP reporter gene assays in adult flies, we confirm that JH is a hormonal immuno-suppressor in vivo. When silencing both partners of the ecdysone receptor (EcR ) / ultraspiracle (USP) heterodimer with RNAi in S2* cells, 20E fails to activate Diptericin (Dpt) expression, suggesting that 20E regulates expression of this gene through EcR / USP signaling. In contrast, silencing methoprene-tolerant (MET), a candidate JH receptor, does not impair the immuno-suppressive action of JH III and JHa, indicating that in this context MET does not function as a JH receptor. Our results suggest that the balance of 20E and JH is a major determinant of immune homeostasis in insects. Experiment Overall Design: To examine the transcriptional response of y, w flies to treatment with exogenous JH, we performed a microarray experiment on females treated with JH or solvent (control). Flies were grown on regular yeast diet, switched to no-yeast food within one hour of eclosion, and yeast-starved for 5 days posteclosion to lower their endogenous JH titer and to synchronize their physiology (cf. Tu and Tatar, 2003; Gershman et al., 2007). Subsequently, we anesthetized flies on ice and topically treated them with 0.1 ïl of 187 mM JH III in acetone or with 0.1ï ïl 100% acetone (control) using a 1 ïl Hamilton syringe with a repeating dispenser. 12 hours after hormone administration, samples were snap-frozen in liquid nitrogen and stored at -80°C. RNA was isolated from samples (2 JH samples, 2 control samples, each with 30 females) by lysis, as described in Gershman et al. (2007). cDNA products were hybridized at the Brown University Genomics Core Facility to Affymetrix GeneChip Drosophila_1 Genome Arrays (2 replicate chips per treatment). The dataset consisted of 14,009 probe sets, with 6,142 probe sets annotated. Expression data were analyzed for significant over- or underrepresentation of gene ontology (GO) terms with the web application FatiGO (Al-Shahrour et al., 2004), using a two-fold change criterion. To test whether JH treatment significantly suppresses expression of AMPs we used t-tests implemented in JMP IN 5.1.
2008-06-16 | E-GEOD-9001 | biostudies-arrayexpress
Project description:The 20-hydroxyecdysone (20E) hierarchy of gene activation serves as an attractive model system for studying the mode of steroid hormone regulated gene expression and development. Primary genes are activated by the direct action of the hormone and often code for proteins with regulatory function, some of which are responsible for the perpetuation of the response through the activation of secondary genes. Here we identify 35 primary 20E-response genes that are induced by 20E in the absence of protein synthesis in the embryonic cell line Kc167, and of those with known functions, most encode proteins with catalytic activity. Comparison of the genome-wide transcriptional response to 20E and to its plant derived structural analog ponasterone A (PoA) revealed a large difference in the transcriptional targets of these molecules. Despite the structural similarity of these two compounds, many more genes related to various aspects of development appear to be significantly induced by 20E than by PoA. Furthermore, we compared the 20E response in Kc cells to that of a natural 20E target tissue where the function of 20E has been well described, the salivary glands of wandering 3rd instar larvae, and found little overlap in 20E-responsive genes. Analysis of 20E-induced transcription of EcR, a known 20E-inducible gene and regulator of early and late 20E-responsive genes, reveals differences in the fold induction of EcR isoforms EcR-RA, ER-RC, and EcR-RD/E between Kc cells and salivary glands suggesting a possible cause for the observed differences in 20E-regulated gene transcription.
2011-12-01 | GSE23928 | GEO
Project description:To identify 20E-regulated genes, wandering third instar larvae were dissected and their organs were cultured in the presence of either no hormone, 20E alone, cycloheximide alone, or 20E plus cycloheximide for six hours. Experiment Overall Design: Eight partial blue gut third instar larvae were dissected in each well of a 9 well glass dish (Corning) and cultured in ~100 µl oxygenated Schneiders Drosophila Medium (Gibco) at 25°C. Cultures were incubated in an a styrofoam box under a constant flow of oxygen. Following an initial incubation of 1 hour, the medium was removed and replaced with either fresh Schneiders Drosophila Medium (no hormone), medium plus 8.5x10-5 M cycloheximide (Sigma), medium plus 5x10-6 M 20-hydroxyecdysone (Sigma), or medium plus cycloheximide and 20E, each for 6 hrs at 25°C. Organs were collected and RNA extracted from these samples was analyzed on Affymetrix Drosophila Genome Arrays.
2007-10-31 | E-GEOD-3060 | biostudies-arrayexpress
Project description:Kc167 cells were mock-treated/treated with combinations of steroid hormone ecdysone and gamma-irradiation, and harvested. The expression profiles were determined using Affymetrix Drosophila Genechip 1 arrays. Comparisons between the sample groups allow the identification of genes with ecdysone- and/or radiation-responsive expression patterns. Experiment Overall Design: 1 set of control, ecdysone, gamma-irradiated, ecdysone + irradiated samples was analyzed.
2008-06-12 | E-GEOD-3072 | biostudies-arrayexpress
Project description:Previously we and other teams have found that 20E modulates the induction and expression of antimicrobial peptides (AMPs) in immune-challenged Drosophila cell culture or whole animals. To identify potential downstream targets of 20E involved in modulating the immune response we used Affymetrix gene chips (microarrays) to compare the transcriptomes of Drosophila S2* cells treated or not with 20E for 24 hours.
2013-04-13 | GSE46020 | GEO
Project description:An intrinsic tumor-suppression mechanism mediated by steroid hormone in Drosophila
| PRJNA394257 | ENA
Project description:Steroid hormones act as important developmental switches and their nuclear receptors regulate many genes. However, few hormone-dependent enhancers have been characterized and important aspects of their sequence architecture, cell type-specific activating and repressing functions, or the regulatory roles of their chromatin structure have remained unclear. We used STARR-seq, a recently developed enhancer-screening assay, and ecdysone signaling in two different Drosophila cell types to derive the first genome-wide hormone-dependent enhancer activity maps. We demonstrate that enhancer activation depends on cis-regulatory motif combinations that differ between cell types and can predict cell type-specific ecdysone targeting. Activated enhancers are often not accessible prior to induction. Enhancer repression following hormone treatment is independent of receptor motifs and receptor binding to the enhancer as we show using ChIP-seq, but appears to rely on motifs for other factors, including Eip74. Our strategy is applicable to study signal-dependent enhancers for different pathways and across organisms. STARR-seq was performed in S2 and OSC cells treated with ecdysone in two replicates. DHS-seq before and after treatment was done with single-end sequencing in two replicates. RNA-seq (with and without ecdysone) was performed with a strand-specific protocol using single-end sequencing in two replicates in S2. ChIP-seq (with and without ecdysone) was performed single-end sequencing in two replicates in S2 cells.
2014-03-27 | E-GEOD-47691 | biostudies-arrayexpress
Project description:Previously we and other teams have found that 20E modulates the induction and expression of antimicrobial peptides (AMPs) in immune-challenged Drosophila cell culture or whole animals. To identify potential downstream targets of 20E involved in modulating the immune response we used Affymetrix gene chips (microarrays) to compare the transcriptomes of Drosophila S2* cells treated or not with 20E for 24 hours. Affymetrix Drosophila 2.0 Chips were probed in triplicate with RNA isolated from untreated S2* cells or cells treated with 1 microMolar 20E (Sigma) for 24 hours. cDNA products were hybridized at the Brown University Genomics Core Facility to Affymetrix GeneChip Drosophila_2.0 Genome Arrays (3 replicate chips per treatment).
2013-04-13 | E-GEOD-46020 | biostudies-arrayexpress