Repression of interrupted and intact rDNA by the SUMO pathway in Drosophila melanogaster
- California Institute of Technology, United States
Abstract
Ribosomal RNAs (rRNAs) are essential components of the ribosome and are among the most abundant macromolecules in the cell. To ensure high rRNA level, eukaryotic genomes contain dozens to hundreds of rDNA genes, however, only a fraction of the rRNA genes seems to be active, while others are transcriptionally silent. We found that individual rDNA genes have high level of cell-to-cell heterogeneity in their expression in Drosophila melanogaster. Insertion of heterologous sequences into rDNA leads to repression associated with reduced expression in individual cells and decreased number of cells expressing rDNA with insertions. We found that SUMO (Small Ubiquitin-like Modifier) and SUMO ligase Ubc9 are required for efficient repression of interrupted rDNA units and variable expression of intact rDNA. Disruption of the SUMO pathway abolishes discrimination of interrupted and intact rDNAs and removes cell-to-cell heterogeneity leading to uniformly high expression of individual rDNA in single cells. Our results suggest that the SUMO pathway is responsible for both repression of interrupted units and control of intact rDNA expression.
Data availability
Sequencing data have been deposited in GEO under accession codes GSE141068 and GSE115277. Other data generated or analysed during this study are included in the manuscript and supporting files.
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Repression of damaged and intact rDNA by the SUMO pathwayNCBI Gene Expression Omnibus, GSE141068.
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The SUMO ligase Su(var)2-10 links piRNA-guided target recognition to chromatin silencingNCBI Gene Expression Omnibus, GSE115277.
Article and author information
Author details
Funding
National Institute of General Medical Sciences (GM097363)
- Alexei Aravin
Howard Hughes Medical Institute (Faculty Scholar Award)
- Alexei Aravin
Ministry of Education and Science of Russian Federation (14.W03.31.0007)
- Alexei Aravin
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Luo et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Repression of interrupted and intact rDNA by the SUMO pathway in Drosophila melanogaster
eLife 9:e52416.
https://doi.org/10.7554/eLife.52416
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