The tudor domain protein Kumo is required to assemble the nuage and to generate germline piRNAs in Drosophila
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE34728 | GEO | 2011/12/31
SECONDARY ACCESSION(S): PRJNA150421
REPOSITORIES: GEO
Similar Datasets
Project description:We are submitting two small RNA libraries derived from ovarian tissue of mutant and heterozygous for the Kumo/Qin gene, required for the piRNA production in germline cells. In absence of Kumo/Qin, piRNA production is reduced and transposons are derepressed. Analysis of piRNA production in Kumo/Qin mutants
2011-12-31 | E-GEOD-34728 | biostudies-arrayexpress
Project description:In Drosophila ovaries, distinct Piwi-interacting RNA (piRNA) pathways defend against transposons in somatic and germline cells. Germline piRNAs predominantly arise from bidirectional clusters and are amplified by the ping-pong cycle. In this study, we characterize a novel Drosophila gene, kumo and show that it encodes a conserved germline piRNA pathway component. Kumo contains five tudor domains and localizes to nuage, a unique structure present in animal germline cells, which is considered to be the processing site for germline piRNAs. Transposons targeted by the germline piRNA pathway are derepressed in kumo mutant females. Moreover, germline piRNA production is significantly reduced in mutant ovaries, thereby indicating that kumo is required to generate germline piRNAs. Kumo localizes to the nuage as well as to nucleus early female germ cells, where it is required to maintain cluster transcript levels. Our data suggest that kumo facilitates germline piRNA production by promoting piRNA cluster transcription in the nucleus and piRNA processing at the nuage.
| S-EPMC3280549 | biostudies-literature
Project description:Understanding the viral piRNA production in mosquitoes
| PRJEB35261 | ENA
Project description:The piRNA pathway, which protects germline genomes from selfish elements such as transposons, operates in two modes: 1) cleavage of transcripts of selfish elements in the cytoplasm, and 2) their transcriptional silencing in the nucleus. Here we describe a novel mechanism by which these two modes exchange the information. We show that the nuclear subpathway component Piwi interacts with the nuage, the compartment that mediates the cytoplasmic subpathway, during mitosis of Drosophila spermatogonia. At the end of mitosis, Piwi leaves nuage to return to the nucleus. We found that dissociation of Piwi from nuage occurs at the depolymerizing microtubules of the central spindle, mediated by a microtubule-depolymerizing kinesin Klp10A. When Piwi’s return to the nucleus is delayed upon klp10A depletion, piRNA production is impacted, suggesting the importance of nuclear-cytoplasmic communication in piRNA biogenesis. We propose that cell cycle-dependent communication of piRNA subpathways plays important roles in coordinated piRNA production.
2018-11-16 | GSE122596 | GEO
Project description:piRNAs are required to maintain germline integrity and fertility but their mechanism of action is poorly understood. Here we demonstrate that C. elegans piRNAs silence transcripts in trans through imperfectly complementary sites. We find that target silencing is independent of Piwi endonuclease activity or “slicing”. Instead, we show that piRNAs initiate a localized secondary endogenous small interfering RNA (endo-siRNA) response. Endogenous protein-coding gene, pseudogene and transposon transcripts exhibit Piwi-dependent endo-siRNAs at sites complementary to piRNAs and are derepressed in Piwi mutants. Genomic loci of piRNA biogenesis are depleted of protein-coding genes but not pseudogenes or transposons. Our data suggest that nematode piRNA clusters are evolving to generate piRNAs against active mobile elements. Thus, piRNAs provide heritable, sequence-specific triggers for RNAi in C. elegans. Affymetrix mRNA expression data from wild-type and two independent prg-1;prg-2 double mutant C. elegans strains (mRNA)
2012-06-17 | E-GEOD-37432 | biostudies-arrayexpress
Project description:piRNAs are required to maintain germline integrity and fertility but their mechanism of action is poorly understood. Here we demonstrate that C. elegans piRNAs silence transcripts in trans through imperfectly complementary sites. We find that target silencing is independent of Piwi endonuclease activity or “slicing”. Instead, we show that piRNAs initiate a localized secondary endogenous small interfering RNA (endo-siRNA) response. Endogenous protein-coding gene, pseudogene and transposon transcripts exhibit Piwi-dependent endo-siRNAs at sites complementary to piRNAs and are derepressed in Piwi mutants. Genomic loci of piRNA biogenesis are depleted of protein-coding genes but not pseudogenes or transposons. Our data suggest that nematode piRNA clusters are evolving to generate piRNAs against active mobile elements. Thus, piRNAs provide heritable, sequence-specific triggers for RNAi in C. elegans.
2012-06-18 | GSE37432 | GEO
Project description:piRNAs are required to maintain germline integrity and fertility but their mechanism of action is poorly understood. Here we demonstrate that C. elegans piRNAs silence transcripts in trans through imperfectly complementary sites. We find that target silencing is independent of Piwi endonuclease activity or “slicing”. Instead, we show that piRNAs initiate a localized secondary endogenous small interfering RNA (endo-siRNA) response. Endogenous protein-coding gene, pseudogene and transposon transcripts exhibit Piwi-dependent endo-siRNAs at sites complementary to piRNAs and are derepressed in Piwi mutants. Genomic loci of piRNA biogenesis are depleted of protein-coding genes but not pseudogenes or transposons. Our data suggest that nematode piRNA clusters are evolving to generate piRNAs against active mobile elements. Thus, piRNAs provide heritable, sequence-specific triggers for RNAi in C. elegans.
2012-06-18 | GSE28617 | GEO
Project description:Piwi-interacting RNAs (piRNAs) are gonad-specific small RNAs that provide defence against transposable genetic elements called transposons. Our knowledge of piRNA biogenesis is sketchy, partly due to an incomplete inventory of the factors involved. Here, we identify Tudor domain-containing 12 (TDRD12; also known as ECAT8) as a novel piRNA biogenesis factor in mice. TDRD12 is detected in complexes containing MILI (PIWIL2), its associated primary piRNAs, and TDRD1, all of which are already implicated in secondary piRNA biogenesis. Male mice carrying either a nonsense point mutation (repro23 mice) or a targeted deletion in the Tdrd12 locus are infertile, and de-repress retrotransposons. We find that TDRD12 is dispensable for primary piRNA biogenesis but essential for production of secondary piRNAs that enter MIWI2 (PIWIL4). Cell culture studies with the insect orthologue of TDRD12 suggest a role for the multi-domain protein in mediating complex formation with other participants during secondary piRNA biogenesis. Total small RNA and immunoprecipitated small RNA were purified from mouse testis extract and Bmn4 cells for preparation of high-throughput sequencing libraries.
2013-11-04 | E-GEOD-50544 | biostudies-arrayexpress
Project description:In animals, genome integrity of the germ line is protected from transposable element (TE) activity by small, non-coding, dedicated RNAs acting as an immune system against TEs, and called PIWI-interacting RNAs (piRNAs) (Czech et al. 2018, Ozata et al. 2018). In Drosophila, the production of piRNAs is initiated from heterochromatic loci containing remnants of TEs and enriched in histone H3 trimethylated on lysine 9 (H3K9me3) (Brennecke et al. 2007, Gunarwardane et al. 2007; Rangan et al. 2011). These loci, called piRNA clusters, constitute a memory of past TE invasions. Little is known about how piRNA clusters are genetically defined. Using a genetic screen combined with a bimodal epigenetic state piRNA cluster (BX2), we identified the splicing factor Half pint (Hfp) and the histone demethylase KDM3 as being able to prevent BX2 piRNA production. Furthermore, we showed that Hfp is needed to splice Kdm3 transcripts. Germline expression of Kdm3 coding sequence (splicing-independent) rescued the hfp germline knock-down (GLKD) effect demonstrating that Kdm3 is sufficient to prevent BX2 piRNA production. Our data revealed that in the absence of Kdm3, dozens of gene-containing regions become bona fide germinal dual strand piRNA clusters. Indeed, they produce piRNAs originating from both DNA strands, become transcribed in a Moonshiner-dependent manner and enriched in di-and tri-methylation of lysine 9 of histone H3 (H3K9me2/3) and in Rhino, an HP1-like protein. Eggs laid by Kdm3 GLKD females do not hatch and show developmental defects phenocopying loss of function of genes included into the new piRNA clusters, suggesting an inheritance of functional ovarian “auto-immune” piRNAs. Our results demonstrate that some gene-containing regions are actively prevented for piRNA production by proteins that counteract piRNA cluster emergence. Hence, a non-piRNA-producing state is therefore not a "by default" state but rather a cellular lock that is actively controlled for some genomic loci.
2023-02-07 | GSE203279 | GEO
Project description:Antisense piRNA amplification, but not piRNA production or nuage assembly, requires the tudor domain protein Qin.
| PRJNA198015 | ENA