Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA203266 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR851837.fastq.gz | Fastqsanger.gz | |||
| SRR851838.fastq.gz | Fastqsanger.gz | |||
| SRR851839.fastq.gz | Fastqsanger.gz | |||
| SRR851840.fastq.gz | Fastqsanger.gz | |||
| SRR851841.fastq.gz | Fastqsanger.gz |
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Project description:The PiwiM-bM-^@M-^SpiRNA complex (PiwiM-bM-^@M-^SpiRISC) in Drosophila ovarian somatic cells represses transposons transcriptionally to maintain genome integrity; however, the underlying mechanisms remain obscure. We performed mRNA-seq analysis from OSCs transfected with siRNAs against CG3893, the known piRNA pathway genes, Piwi, Maelstrom, HP1a and Armitage, and the control (EGFP), and PolII ChIP-seqanalysis from OSCs transfected with siRNAs against CG3893, Piwi, Mael and the control (EGFP). This result indicates that CG3893 is a novel factor for primary piRNA pathway in OSCs. RNA levels in wild-type (EGFP control knock-down) ovarian somatic cells (OSC) and RNAi knock-downs of Piwi, Armi, Mael, CG3893, and HP1a. RNA Polymerase II occupancy in wild-type (EGFP control knock-down) ovarian somatic cells (OSC) and RNAi knock-downs of Piwi, Mael, and CG3893.
2013-08-01 | E-GEOD-47006 | biostudies-arrayexpress
Project description:Eukaryotic genomes are colonized by transposable elements whose uncontrolled activity results in genomic instability. The piRNA pathway silences transposons in animal gonads, yet how this is achieved molecularly remains controversial. We assign an essential role to the HMG protein Maelstrom in the process of Piwi mediated silencing in Drosophila. Genome wide assays revealed highly correlated changes in RNA Polymerase II recruitment, nascent RNA output and steady state RNA levels of transposons upon loss of Piwi or Maelstrom. Our data demonstrate piRNA-mediated trans- silencing of hundreds of transposon copies at the transcriptional level. We show that Piwi is required for establishing heterochromatic H3K9me3 marks on transposons and their genomic surrounding. In contrast, loss of Maelstrom impacts transposon H3K9me3 patterns only marginally yet leads to increased heterochromatin spreading, suggesting that Maelstrom acts downstream of or in parallel to H3K9me3. Our work uncovers the widespread influence of transposons and the piRNA pathway on chromatin patterns and gene expression programs. RNA Polymerase II and H3K9me3 occupancy, and steady-state and nascent RNA levels in wild-type ovarian somatic cells (OSC) and RNAi knock-downs of the piRNA pathway components. RNA Polymerase II occupancy in tissue-specific knockdowns of tejas (control) and armi in somatic cells of Drosophila ovary.
2012-11-26 | E-GEOD-41729 | biostudies-arrayexpress
Project description:In animal gonads, 23-30nt long PIWI interacting RNAs (piRNAs) guarantee genome integrity by guiding the sequence specific silencing of selfish genetic elements such as transposons. Two major branches of piRNA biogenesis, namely primary processing and ping-pong amplification, feed into the PIWI clade of Argonaute proteins. Despite our conceptual understanding of piRNA biogenesis, major gaps exist in the mechanistic understanding of the underlying molecular processes as well as in the knowledge of the involved players. Here, we demonstrate an essential role for the female sterility gene shutdown in the piRNA pathway. Shutdown, an evolutionarily conserved co-chaperone of the immunophilin class is the first piRNA biogenesis factor that is essential for all primary and secondary piRNA populations in Drosophila. Based on these findings, we define distinct groups of piRNA biogenesis factors and reveal the core concept of how PIWI family proteins are hard-wired into piRNA biogenesis processes. small-RNA libraries from 2 control samples and 7 knock-down samples of D. mel. ovaries and 2 small-RNA profiles from Piwi IP and Aub IP from OSCs.
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Project description:In the Metazoan germline, piwi proteins and associated piwi-interacting RNAs (piRNAs) provide a defense system against the expression of transposable elements. In the cytoplasm, piRNA sequences guide piwi complexes to destroy complementary transposon transcripts by endonucleolytic cleavage. However, some piwi family members are nuclear, raising the possibility of alternative pathways for piRNA-mediated regulation of gene expression. We found that Drosophila Piwi is recruited to chromatin, co-localizing with RNA polymerase II on polytene chromosomes. Knockdown of Piwi in the germline increases expression of transposable elements that are targeted by piRNAs, whereas protein-coding genes remain largely unaffected. De-repression of transposons upon Piwi depletion correlates with increased occupancy of RNA polymerase II on their promoters. Expression of piRNAs that target a reporter construct results in a decrease in Pol II occupancy and an increase in repressive H3K9me3 marks and HP1 on the reporter locus. Our results indicate that Piwi identifies targets complementary to the associated piRNA and induces transcriptional repression by establishing a repressive chromatin state when correct targets are found. Examination of mRNA levels, Pol II occupancy, and chromatin repressive state in D. melanogaster ovaries upon Piwi knockdown and Piwi mutation. This records present the sequencing data related to Piwi knockdown study portion.
2013-02-11 | E-GEOD-43829 | biostudies-arrayexpress
Project description:The Piwi–piRNA complex (Piwi–piRISC) in Drosophila ovarian somatic cells represses transposons transcriptionally to maintain genome integrity; however, the underlying mechanisms remain obscure. We performed mRNA-seq analysis from OSCs transfected with siRNAs against CG3893, the known piRNA pathway genes, Piwi, Maelstrom, HP1a and Armitage, and the control (EGFP), and PolII ChIP-seqanalysis from OSCs transfected with siRNAs against CG3893, Piwi, Mael and the control (EGFP). This result indicates that CG3893 is a novel factor for primary piRNA pathway in OSCs.
2013-08-01 | GSE47006 | GEO
Project description:piRNAs are 26-30nt germ-line specific small non-coding RNAs that have evolutionarily conserved function in mobile genetic element silencing and maintenance of genome integrity. It has been shown that Drosophila Hsp70/90 Organizing Protein Homolog (Hop) – a co-chaperone interacts with piRNA binding protein Piwi and mediates silencing of phenotypic variations. However, it is not known if Hop has a direct role in piRNA biogenesis and transposon silencing. Here, we show that knock down of Hop in the germ-line nurse cells (GLKD) of Drosophila ovaries leads to activation of transposable elements. Females without germ-line Hop can lay eggs but the eggs do not hatch into larvae. GLKD of Hop leads to accumulation of γ-H2Av foci in the germline indicating increased DNA damage in the ovary. We also show that Hop is required for efficient piRNA biogenesis. Based on these results, we conclude that Hop is a critical component of piRNA pathway and it maintains genome integrity by silencing transposable elements.
2017-06-30 | GSE93934 | GEO
Project description:In the Metazoan germline, piwi proteins and associated piwi-interacting RNAs (piRNAs) provide a defense system against the expression of transposable elements. In the cytoplasm, piRNA sequences guide piwi complexes to destroy complementary transposon transcripts by endonucleolytic cleavage. However, some piwi family members are nuclear, raising the possibility of alternative pathways for piRNA-mediated regulation of gene expression. We found that Drosophila Piwi is recruited to chromatin, co-localizing with RNA polymerase II on polytene chromosomes. Knockdown of Piwi in the germline increases expression of transposable elements that are targeted by piRNAs, whereas protein-coding genes remain largely unaffected. De-repression of transposons upon Piwi depletion correlates with increased occupancy of RNA polymerase II on their promoters. Expression of piRNAs that target a reporter construct results in a decrease in Pol II occupancy and an increase in repressive H3K9me3 marks and HP1 on the reporter locus. Our results indicate that Piwi identifies targets complementary to the associated piRNA and induces transcriptional repression by establishing a repressive chromatin state when correct targets are found.
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Project description:PIWI-interacting RNAs (piRNAs) are genomically-encoded small RNAs that regulate germ cell development and guarantee germline integrity. Mature piRNAs engage Piwi Argonaute proteins to silence complementary transcripts, including transposable elements and endogenous genes. To date, piRNA biogenesis mechanisms are still unclear. Here, we show that the RNA Polymerase II subunit RPB-9 is required to promote transcription elongation at piRNA loci. Through genetic and biochemical experiments, we demonstrate that rpb-9-mediated piRNA production is needed to repress two DNA transposon families and a subset of somatic genes in the C. elegans germline.
2020-12-07 | PXD018657 | Pride
Project description:Piwi-interacting RNAs (piRNAs) suppress transposon activity in animal germ cells. In the Drosophila ovary, primary Aubergine (Aub)-bound antisense piRNAs initiate the ping-pong cycle to produce secondary AGO3-bound sense piRNAs. This increases the number of secondary Aub-bound antisense piRNAs that can act to destroy transposon mRNAs. Here we show that Krimper (Krimp), a Tudor-domain protein, directly interacts with piRNA-free AGO3 to promote symmetrical dimethylarginine (sDMA) modification, ensuring sense piRNA-loading onto sDMA-modified AGO3. In aub mutant ovaries, AGO3 associates with ping-pong signature piRNAs, suggesting AGO3’s compatibility with primary piRNA loading. Krimp sequesters ectopically expressed AGO3 within Krimp bodies in cultured ovarian somatic cells (OSCs), in which only the primary piRNA pathway operates. Upon krimp-RNAi in OSCs, AGO3 loads with piRNAs, further showing the capacity of AGO3 for primary piRNA loading. We propose that Krimp enforces an antisense bias on piRNA pools by binding AGO3 and blocking its access to primary piRNAs. In order to investigate function of Krimp in piRNA pathway, sequencing of Piwi subfamily protein associated small RNAs was performed using adult Drosophila ovaries and Ovarian Somatic Cells (OSCs) depleted for Krimp or Aub.
2015-05-28 | E-GEOD-69293 | biostudies-arrayexpress
Project description:RNAi-related silencing mechanisms concern as diverse biological processes as gene regulation, mostly via the miRNA pathway, and defense against molecular parasites, mainly controlled by the siRNA and the piRNA pathways. In Drosophila somatic ovarian cells, transposable elements (TEs) are repressed by chromatin changes induced by Piwi-interacting RNAs (piRNAs). We show here that a functional miRNA pathway is required for this piRNA-mediated TE transcriptional silencing to operate in this tissue. A general miRNA depletion, caused by tissue- and stage-specific knock-down of either drosha (involved in miRNA biogenesis) or AG01 and gawky (both responsible for miRNA activity) resulted in chromatin-mediated TE transcriptional desilencing and piRNA loss. For unknown reasons, the amount of piRNA produced by the traffic jam 3' UTR was apparently unaffected in miRNA-defective somatic ovarian cells. Although weaker, similar phenotypes could also be observed upon individual titration (by expression of the complementary miR-sponge) of at least three miRNAs, miR-14, miR-34 and miR-989. This work adds the maintenance of genome stability, via the piRNA-mediated TE repression, to the list of the already reported miRNA-controlled biological functions. Analyses of RNA present in 3 different genetic backgounds with or without Drosha-IP: a control, a second one expressing the wild-type Drosha protein and a third one expressing the trans-dominant negative Drosha protein in the somatic cells.
2015-04-08 | E-GEOD-60973 | biostudies-arrayexpress