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Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression

Eukaryotic genomes are colonized by transposons whose uncontrolled activity causes genomic instability. The piRNA pathway silences transposons in animal gonads, yet how this is achieved molecularly remains controversial. Here, we show that the HMG protein Maelstrom is essential for Piwi-mediated sil...

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Detalles Bibliográficos
Autores principales: Sienski, Grzegorz, Dönertas, Derya, Brennecke, Julius
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cell Press 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3504300/
https://www.ncbi.nlm.nih.gov/pubmed/23159368
http://dx.doi.org/10.1016/j.cell.2012.10.040
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author Sienski, Grzegorz
Dönertas, Derya
Brennecke, Julius
author_facet Sienski, Grzegorz
Dönertas, Derya
Brennecke, Julius
author_sort Sienski, Grzegorz
collection PubMed
description Eukaryotic genomes are colonized by transposons whose uncontrolled activity causes genomic instability. The piRNA pathway silences transposons in animal gonads, yet how this is achieved molecularly remains controversial. Here, we show that the HMG protein Maelstrom is essential for 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 to establish heterochromatic H3K9me3 marks on transposons and their genomic surroundings. In contrast, loss of Maelstrom affects transposon H3K9me3 patterns only mildly yet leads to increased heterochromatin spreading, suggesting that Maelstrom acts downstream of or in parallel to H3K9me3. Our work illustrates the widespread influence of transposons and the piRNA pathway on chromatin patterns and gene expression.
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spelling pubmed-35043002012-12-05 Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression Sienski, Grzegorz Dönertas, Derya Brennecke, Julius Cell Article Eukaryotic genomes are colonized by transposons whose uncontrolled activity causes genomic instability. The piRNA pathway silences transposons in animal gonads, yet how this is achieved molecularly remains controversial. Here, we show that the HMG protein Maelstrom is essential for 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 to establish heterochromatic H3K9me3 marks on transposons and their genomic surroundings. In contrast, loss of Maelstrom affects transposon H3K9me3 patterns only mildly yet leads to increased heterochromatin spreading, suggesting that Maelstrom acts downstream of or in parallel to H3K9me3. Our work illustrates the widespread influence of transposons and the piRNA pathway on chromatin patterns and gene expression. Cell Press 2012-11-21 /pmc/articles/PMC3504300/ /pubmed/23159368 http://dx.doi.org/10.1016/j.cell.2012.10.040 Text en © 2012 ELL & Excerpta Medica. https://creativecommons.org/licenses/by-nc-nd/3.0/ Open Access under CC BY-NC-ND 3.0 (https://creativecommons.org/licenses/by-nc-nd/3.0/) license
spellingShingle Article
Sienski, Grzegorz
Dönertas, Derya
Brennecke, Julius
Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression
title Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression
title_full Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression
title_fullStr Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression
title_full_unstemmed Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression
title_short Transcriptional Silencing of Transposons by Piwi and Maelstrom and Its Impact on Chromatin State and Gene Expression
title_sort transcriptional silencing of transposons by piwi and maelstrom and its impact on chromatin state and gene expression
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3504300/
https://www.ncbi.nlm.nih.gov/pubmed/23159368
http://dx.doi.org/10.1016/j.cell.2012.10.040
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