Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

31 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The evolution of genic piRNA cluster loci expression patterns

ABSTRACT: This study examines the conservation of Piwi-interacting RNA (piRNA) clusters that come from protein coding gene transcripts. By sequencing small RNA libraries from gonad tissues of Drosophilids and Glires we discover a diverse set of genic piRNA clusters conserved across animals. This dataset reveals new expression patterns for genic piRNA clusters and examines whether changing piRNA expression patterns correlates with sequence changes in piRNA cluster genomic sequence across a variety of animal species. We dissected gonad tissues consisting of ovaries from wildtype adult Drosophilids (D.melanogaster, D.erecta, D.yakuba, D.virilis) and testes from wildtype pre-pubsecent and adult mouse and rats. Adult testes from rabbits were purchased from Pel-Freez Biologicals. Total or immunopreciptated RNAs were extracted from the pulvirized gonad tissues of Drosophilids and Glires. Small RNAs were purified from these samples, converted into cDNA libraries, and sequenced on an Illumina HiSeq2000.

ORGANISM(S): Drosophila melanogaster

SUBMITTER: Nelson Lau

PROVIDER: E-GEOD-62556 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

The evolution of genic piRNA cluster loci expression patterns

Project description:This study examines the conservation of Piwi-interacting RNA (piRNA) clusters that come from protein coding gene transcripts. By sequencing small RNA libraries from gonad tissues of Drosophilids and Glires we discover a diverse set of genic piRNA clusters conserved across animals. This dataset reveals new expression patterns for genic piRNA clusters and examines whether changing piRNA expression patterns correlates with sequence changes in piRNA cluster genomic sequence across a variety of animal species.

2015-11-01 | GSE62556 | GEO

Major concepts of piRNA biogenesis revealed by the analysis of Shutdown, a co-chaperone with essential roles in the biogenesis of all Drosophila piRNA populations

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.

2012-06-29 | E-GEOD-38728 | biostudies-arrayexpress

The Rhino-Deadlock-Cutoff complex licenses non-canonical transcription of dual-strand piRNA clusters in Drosophila

Project description:Argonaute proteins of the PIWI clade are central to transposon silencing in animal gonads. Their target specificity is defined by 22-30nt PIWI interacting RNAs (piRNAs), which mostly originate from discrete genomic loci termed piRNA clusters. Here we show that the RDC complex composed of Rhino, Deadlock and Cutoff defines dual-strand piRNA clusters genome-wide in Drosophila ovaries. The RDC complex is anchored to H3K9me3-marked chromatin in part via RhinoM-bM-^@M-^Ys chromo-domain. Depletion of Piwi results in loss of the RDC and small RNAs at euchromatic piRNA source loci, demonstrating a feedback loop between Piwi and genomic piRNA sources. Intriguingly, profiles of RNA Polymerase II occupancy, nascent transcription and steady-state RNA levels reveal that the RDC licenses non-canonical transcription of dual-stranded piRNA clusters. Likely, this process involves 5M-bM-^@M-^Yend protection of nascent RNAs and subsequent suppression of transcription termination. Together, our data provide a comprehensive model for the regulation and evolution of piRNA clusters. This study aims at indentifying and characterizing genimc sources of piRNA percursour transcripts using genome-wide apporaches such as ChIP-seq, RNA-seq, smallRNA-seq and GRO-seq in adult Drosophila ovaries depleted for several factors implicated in piRNA cluster regulation

2014-06-08 | E-GEOD-55824 | biostudies-arrayexpress

Xenopus Piwi protein associated transcripts indicate regulation beyond transposons

Project description:This study examines the population of transcripts associated with the Xenopus Piwi proteins, Xiwi and Xili, from X.laevis and X.tropicalis. RIP-seq, CLIP-seq, piRNA-seq, and mRNA-seq datasets were integrated to determine how the Xenopus Piwi proteins where using piRNAs and binding interactions to associate with transcripts in gonadal cells. We performed several replicates of a Piw CLIP-Seq experiment to isolate RNA fragments as CLIP-tags to discover which transcripts are preferentially bound by the Piwi protein. Then we performed several types of mRNA expression profiling experiments using several forms of mRNA-Seq library construction formats. Finally, we sequenced the piRNAs from the OSS cells

2015-11-10 | E-GEOD-63228 | biostudies-arrayexpress

Euchromatic transposon insertions trigger production of novel pi- and endo-siRNAs at the target sites in the Drosophila germline

Project description:The control of transposable element (TE) activity in germ cells provides genome integrity over generations. A distinct small RNA-mediated pathway utilizing Piwi-interacting RNAs (piRNAs) suppresses TE expression in gonads of metazoans. In the fly, primary piRNAs derive from so-called piRNA clusters, which are enriched in damaged repeated sequences. These piRNAs launch a cycle of TE and piRNA cluster transcript cleavages resulting in the amplification of piRNA and TE silencing. Using genome-wide comparison of TE insertions and ovarian small RNA libraries from two Drosophila strains, we found that individual TEs inserted into euchromatic loci form novel dual-stranded piRNA clusters. Formation of the piRNA-generating loci by active individual TEs provides a more potent silencing response to the TE expansion. Like all piRNA clusters, individual TEs are also capable of triggering the production of endogenous small interfering (endo-si) RNAs. Small RNA production by individual TEs spreads into the flanking genomic regions including coding cellular genes. We show that formation of TE-associated small RNA clusters can down-regulate expression of nearby genes in ovaries. Integration of TEs into the 3' untranslated region of actively transcribed genes induces piRNA production towards the 3'-end of transcripts, causing the appearance of genic piRNA clusters, a phenomenon that has been reported in different organisms. These data suggest a significant role of TE-associated small RNAs in the evolution of regulatory networks in the germline. The fractions of small RNAs (19-29 nt) from ovaries of y[1]; cn[1] bw[1] sp[1] line of Drosophila melanogaster were sequenced using Illumina HiSeq 2000.

2014-02-07 | E-GEOD-46105 | biostudies-arrayexpress

A piRNA pathway primed by individual transposons is linked to de novo DNA methylation in mice

Project description:We examined the construction of the piRNA system in the restricted developmental window in which methylation patterns are set during mammalian embryogenesis. We find robust expression of two Piwi family proteins, MIWI2 and MILI. Their associated piRNA profiles reveal differences from Drosophila wherein large piRNA clusters act as master regulators of silencing. Instead, in mammals, dispersed transposon copies initiate the pathway, producing primary piRNAs, which predominantly join MILI in the cytoplasm. MIWI2, whose nuclear localization and association with piRNAs depend upon MILI, is enriched for secondary piRNAs antisense to the elements that it controls. The Piwi pathway lies upstream of known mediators of DNA methylation, since piRNAs are still produced in Dnmt3L mutants, which fail to methylate transposons. This implicates piRNAs as specificity determinants of DNA methylation in germ cells. Examination of total small RNA and MILI associated piRNAs in embryonic and post-birth mouse testes, MIWI2-associated piRNAs in embryonic testes.

2008-10-01 | E-GEOD-12757 | biostudies-arrayexpress

RNA elements in precursors instruct directional and processive primary piRNA biogenesis

Project description:PIWI-interacting RNAs (piRNAs) are animal gonad-specific small RNAs that control the activity of transposable elements. Long single stranded RNAs from a variety of sources are substrates for the nebulous primary processing pathway that converts these into thousands of 24-30 nucleotide (nt) piRNAs. How these transcripts are selected as precursors is not known. Here we show that targeting a transcript with PIWI slicer activity of cysosolic Ago3 is sufficient to trigger ~30-nt waves of non-overlapping primary piRNAs in the fly ovarian germline. The generated primary piRNAs are almost exclusively loaded into the nuclear PIWI protein, Piwi. In the fly ovarian somatic environment we find that an RNA fragment from the 5? end of a piRNA cluster is able to direct a heterologous sequence into primary processing. This piRNA trigger sequence (PTS) element drives generation of overlapping piRNAs from the transcript. Both mechanisms proceed with general 5?-3? directionality. We propose that the former pathway serves to link cytoplasmic silencing of a target to nuclear transcriptional repression, while the latter extracts silencing information from a wide variety of genomic sources including piRNA clusters, select protein coding and transposon transcripts. Total or immunoprecipitated small RNAs were purified from transfected BmN4 cells, Drosophila ovarian somatic cells (OSC) and from fly ovaries and high-throughput sequencing libraries were prepared. The mouse testicular RNAs were purified after ribozero treatment.

2015-07-09 | E-GEOD-69102 | biostudies-arrayexpress

Small RNA and gene expression profile in the adult testes of the common marmoset

Project description:Small RNAs mediate gene silencing by binding Argonaute/Piwi proteins to regulate target RNAs. Here we describe small RNA profiling of the adult testes of Callithrix jacchus, the common marmoset. The most abundant class of small RNAs in the adult testis was piRNAs, while 353 novel miRNAs but few endo-siRNAs were also identified. MARWI, a marmoset homolog of mouse MIWI and a very abundant PIWI in adult testes, associates with piRNAs that show characteristics of mouse pachytene piRNAs. As in other mammals, most marmoset piRNAs are derived from conserved clustered regions in the genome, which are annotated as intergenic regions. However, some of these piRNA cluster regions contain antisense-orientated pseudogenes, suggesting regulation of parental functional protein-coding genes. More piRNAs map to transposable element (TE) subfamilies when they have copies in piRNA clusters. In addition, the strand-bias observed for piRNAs mapped to each TE subfamily correlates with the polarity of copies inserted in clusters. These findings suggest that pachytene piRNA clusters determine the abundance and strand-bias of TE-derived piRNAs, and also regulate protein-coding genes via pseudogene-derived piRNAs. small RNA levels in the adult marmoset testis, and MARWI-IP small RNA levels and RNA levels from the adult marmoset testis with two replicates.

2014-06-01 | E-GEOD-52927 | biostudies-arrayexpress

FLX sequencing of Piwi-associated small RNAs extracted from Drosophila ovarian somatic cells (OSC)

Project description:piRNAs function in silencing retrotransposons by associating with the PIWI proteins, AGO3, Aub, and Piwi, in Drosophila germlines. Bioinformatics analyses of piRNAs in Drosophila ovaries suggested that piRNAs are produced by two systems, the primary processing pathway and the amplification loop, from repetitive genes and piRNA clusters in the genome. The amplification loop occurs in a Dicer-independent, PIWI-Slicer-dependent manner. However, the primary processing pathway remains largely conceptual. Here we show that in ovarian somatic cells, which lack Aub and AGO3 but express Piwi, the primary processing pathway for piRNAs indeed exists. Keywords: Small RNA profiling by high throughput sequencing Piwi-associated small RNAs were extracted from Drosophila ovarian somatic cells and their deep sequencing was carried out.

2009-10-01 | E-GEOD-15137 | biostudies-arrayexpress

piRNA libraries from Drosophila melanogaster ovaries

Project description:Drosophila Piwi-family proteins have been implicated in transposon control. Here, we examine piwi-interacting RNAs (piRNAs) associated with each Drosophila Piwi protein and find that Piwi and Aubergine bind RNAs that are predominantly antisense to transposons, whereas Ago3 complexes contain predominantly sense piRNAs. As in mammals, the majority of Drosophila piRNAs are derived from discrete genomic loci. These loci comprise mainly defective transposon sequences, and some have previously been identified as master regulators of transposon activity. Our data suggest that heterochromatic piRNA loci interact with potentially active, euchromatic transposons to form an adaptive system for transposon control. Complementary relationships between sense and antisense piRNA populations suggest an amplification loop wherein each piRNA-directed cleavage event generates the 5’ end of a new piRNA. Thus, sense piRNAs, formed following cleavage of transposon mRNAs, may enhance production of antisense piRNAs, complementary to active elements, by directing cleavage of transcripts from master control loci. Keywords: small RNA libraries from Drosophila ovaries small RNAs (23-29nt) were isolated from total ovarian RNA or from immunopreciptated Piwi/Aubergine/Ago3 complexes. cDNA libraries were constructed after Pfeffer et al. 2005 (Nat. Methods) and sequenced at 454 Life Sciences. The used strain is OregonR. Only sequences matching the Release5 genome assembly (www.fruitfly.org) are considered.

2007-03-08 | E-GEOD-6734 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data