Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Naïve RNA Sampling Core Enables Adaptive piRNA Specificity Against Transposable Elements [smallRNA]

ABSTRACT: How piRNA-mediated genome defense achieves specificity against transposons while sampling a complex transcriptome has remained unresolved. Here we show that piRNA biogenesis operates through pervasive, non-specific sampling of cytoplasmic RNAs, with specificity imposed by tissue-specific molecular modules that exploit intrinsic vulnerabilities of transposons. In Drosophila somatic cells, the specificity factor Yb steers basal processing towards uridine-rich RNAs—automatically capturing antisense retrotransposon transcripts due to their intrinsically adenosine-biased genomes. In germline cells lacking Yb, basal sampling generates naïve piRNAs loaded into catalytically active Argonaute proteins, which trigger autocatalytic ping-pong amplification upon encountering complementary targets. In both contexts, transposon mobility facilitates the production of antisense RNAs that enable either biased processing or amplification. Thus, piRNA clusters, long associated with pathway specificity, act as sources of transposon antisense sequences, while specificity arises from layering distinct molecular mechanisms onto a shared foundation of indiscriminate transcript sampling, enabling robust and adaptable genome defense without predefined templates.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE320062 | GEO | 2026/02/23

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

A Naïve RNA Sampling Core Enables Adaptive piRNA Specificity Against Transposable Elements [CLIP]

Project description:How piRNA-mediated genome defense achieves specificity against transposons while sampling a complex transcriptome has remained unresolved. Here we show that piRNA biogenesis operates through pervasive, non-specific sampling of cytoplasmic RNAs, with specificity imposed by tissue-specific molecular modules that exploit intrinsic vulnerabilities of transposons. In Drosophila somatic cells, the specificity factor Yb steers basal processing towards uridine-rich RNAs—automatically capturing antisense retrotransposon transcripts due to their intrinsically adenosine-biased genomes. In germline cells lacking Yb, basal sampling generates naïve piRNAs loaded into catalytically active Argonaute proteins, which trigger autocatalytic ping-pong amplification upon encountering complementary targets. In both contexts, transposon mobility facilitates the production of antisense RNAs that enable either biased processing or amplification. Thus, piRNA clusters, long associated with pathway specificity, act as sources of transposon antisense sequences, while specificity arises from layering distinct molecular mechanisms onto a shared foundation of indiscriminate transcript sampling, enabling robust and adaptable genome defense without predefined templates.

2026-02-23 | GSE320061 | GEO

A Naïve RNA Sampling Core Enables Adaptive piRNA Specificity Against Transposable Elements [RNA]

2026-02-23 | GSE320060 | GEO

Distinct and collaborative functions of Yb and Armitage in transposon-targeting piRNA biogenesis

Project description:PIWI-interacting RNAs (piRNAs) repress transposons to maintain germline genome integrity. Previous studies showed that artificial tethering of Armitage (Armi) to reporter RNAs induced piRNA biogenesis. However, lack of female sterile (1) Yb (Yb) in Drosophila ovarian somatic cells (OSCs) impaired production of transposon-targeting piRNAs even in the presence of Armi. Here, we show that specific interaction of Armi with RNA transcripts of flamenco piRNA cluster, the primary source of transposon-targeting piRNAs in OSCs, is strictly regulated by Yb. Lack of Yb allowed Armi to bind RNAs promiscuously, leading to the production of piRNAs unrelated to transposon silencing. The ATP hydrolysis-defective mutants of Armi failed to unwind RNAs and were retained on them, abolishing piRNA production. These findings shed light on distinct and collaborative requirements of Yb and Armi in transposon-targeting piRNA biogenesis. We also provide evidence supporting the direct involvement of Armi but not Yb in Zucchini-dependent piRNA phasing.

2019-03-28 | GSE128924 | GEO

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

2007-03-08 | GSE6734 | GEO

High throughput sequencing of Piwi bound piRNAs from Drosophila ovaries in which key factors for primary piRNA biogenesis in somatic support cells were knocked down using RNAi

Project description:In Drosophila, PIWI proteins and bound PIWI interacting RNAs (piRNAs) form the core of a small RNA mediated defense system against selfish genetic elements. Within germline cells piRNAs are processed from piRNA clusters and transposons to be loaded into Piwi/Aubergine/AGO3 and a subset of piRNAs undergoes target dependent amplification. In contrast, gonadal somatic support cells express only Piwi, lack signs of piRNA amplification and exhibit primary piRNA biogenesis from piRNA clusters. Neither piRNA processing/loading nor Piwi mediated target silencing is understood at the genetic, cellular or molecular level. We developed an in vivo RNAi assay for the somatic piRNA pathway and identified the RNA helicase Armitage, the Tudor domain containing RNA helicase Yb and the putative nuclease Zucchini as essential factors for primary piRNA biogenesis. Lack of any of these proteins leads to transposon de-silencing, to a collapse in piRNA levels and to a failure in Piwi nuclear accumulation. We show that Armitage and Yb interact physically and co-localize in cytoplasmic Yb-bodies, which flank P-bodies. Loss of Zucchini leads to an accumulation of Piwi and Armitage in Yb-bodies indicating that Yb-bodies are sites of primary piRNA biogenesis.

2010-10-04 | GSE23560 | GEO

High throughput sequencing of Piwi bound piRNAs from Drosophila ovaries in which key factors for primary piRNA biogenesis in somatic support cells were knocked down using RNAi

2010-10-03 | E-GEOD-23560 | biostudies-arrayexpress

piRNA libraries from Drosophila melanogaster ovaries

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

Requirements for multivalent Yb body assembly in transposon silencing in Drosophila

Project description:Female sterile (1) Yb (Yb) is a primary component of Yb bodies, perinuclear foci known as the site of PIWI-interacting RNA (piRNA) biogenesis in Drosophila ovarian somatic cells. Yb consists of Helicase C-terminal (Hel-C), RNA helicase and extended Tudor (eTud) domains. We previously showed that the RNA helicase domain is necessary for Yb−RNA interaction, Yb body formation and piRNA biogenesis. Here, we investigated the functions of the two other domains and found that Hel-C and eTud are necessary for Yb to self-associate and to interact with RNAs and other Yb body components, respectively. Both domains were essential for Yb body formation and transposon silencing. Without eTud, piRNA production was completely impaired. Loss of Hel-C severely reduced the levels of transposon-targeting piRNAs, although genic piRNAs unrelated to transposon silencing were still produced. Similar phenotypes were observed when mutations in flamenco, the primary source of transposon-targeting piRNAs, led to the expression of attenuated RNAs. Yb bodies are liquid-like multivalent condensates whose assembly depends on Yb self-association and widespread Yb−flamenco RNA binding.

2019-04-29 | GSE121605 | GEO

the analysis of piRNA shows the function of Slicer activity of AGO3 in piRNA biogenesis.

Project description:Piwi-interacting RNAs (piRNAs) silence transposons in animal germ cells. In Drosophila, the reciprocal “Ping-Pong” cycle of piRNA-directed RNA cleavage, catalyzed by the PIWI proteins Aubergine (Aub) and Argonaute3 (AGO3) through their Slicer activity, is believed to expand the population of antisense piRNAs in response to transposon expression. Whether and how the Slicer activity of AGO3/Aub promotes the process of the secondary piRNA amplification remain unclear. Here we generated transgenic flies that could express AGO3 Slicer mutant forms to ellucidate the Slicer activity of AGO3.

2014-06-30 | GSE49436 | GEO

the analysis of piRNA shows the function of Slicer activity of AGO3 in piRNA biogenesis.

2014-06-30 | E-GEOD-49436 | biostudies-arrayexpress