EGO-1, a Putative RNA-Dependent RNA Polymerase, Is Required for Heterochromatin Assembly on Unpaired DNA during C. elegans Meiosis
| Autor: | Jessica Hauth, Valarie E. Vought, Xingyu She, Eleanor M. Maine, Thomas Ratliff, William G. Kelly |
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| Rok vydání: | 2005 |
| Předmět: |
Models
Molecular Heterochromatin Cell Cycle Proteins Methylation Article General Biochemistry Genetics and Molecular Biology RNA interference Animals Gene Silencing Protein Methyltransferases Heterochromatin assembly Caenorhabditis elegans Caenorhabditis elegans Proteins Fluorescent Antibody Technique Indirect Drosha Genetics Agricultural and Biological Sciences(all) biology Biochemistry Genetics and Molecular Biology(all) RNA DNA Histone-Lysine N-Methyltransferase RNA-Dependent RNA Polymerase biology.organism_classification Chromatin Meiosis Mutation Histone Methyltransferases biology.protein General Agricultural and Biological Sciences Dicer |
| Zdroj: | Current Biology. 15:1972-1978 |
| ISSN: | 0960-9822 |
| Popis: | SummaryDuring meiosis in C. elegans, unpaired chromosomes and chromosomal regions accumulate high levels of histone H3 lysine 9 dimethylation (H3K9me2), a modification associated with facultative heterochromatin assembly and the resulting transcriptional silencing [1, 2]. Meiotic silencing of unpaired DNA may be a widely conserved genome defense mechanism [3–5]. The mechanisms of meiotic silencing remain unclear, although both transcriptional and posttranscriptional processes are implicated [3–5]. Cellular RNA-dependent RNA polymerases (RdRPs) function in development and RNA-mediated silencing in many species [3, 6, 7] and in heterochromatin assembly in S. pombe [3, 8]. There are four C. elegans RdRPs, including two with known germline functions. EGO-1 is required for fertility and robust germline RNAi [9–11]. RRF-3 acts genetically to repress RNAi and is required for normal meiosis and spermatogenesis at elevated temperatures [12] (S. L’Hernault, personal communication). Among C. elegans RdRPs, we find that only EGO-1 is required for H3K9me2 enrichment on unpaired chromosomal regions during meiosis. This H3K9me2 enrichment does not require Dicer or Drosha nuclease or any of several other proteins required for RNAi. ego-1 interacts genetically with him-17, another regulator of chromatin and meiosis [13], to promote germline development. We conclude that EGO-1 is an essential component of meiotic silencing in C. elegans. |
| Databáze: | OpenAIRE |
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