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Intergenic transcripts originating from a subclass of ribosomal DNA repeats silence ribosomal RNA genes in trans.

ABSTRACT: Epigenetic silencing of a fraction of ribosomal DNA (rDNA) requires association of the nucleolar chromatin-remodelling complex NoRC to 150-250 nucleotide RNAs (pRNA) that originate from an RNA polymerase I promoter located in the intergenic spacer separating rDNA repeats. Here, we show that NoRC-associated pRNA is transcribed from a sub-fraction of hypomethylated rRNA genes during mid S phase, acting in trans to inherit DNA methylation and transcriptional repression of late-replicating silent rDNA copies. The results reveal variability between individual rDNA clusters with distinct functional consequences.

SUBMITTER: Santoro R

PROVIDER: S-EPMC2816622 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature

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Intergenic transcripts originating from a subclass of ribosomal DNA repeats silence ribosomal RNA genes in trans.

Santoro Raffaella R Schmitz Kerstin-Maike KM Sandoval Juan J Grummt Ingrid I

EMBO reports 20091204 1

Epigenetic silencing of a fraction of ribosomal DNA (rDNA) requires association of the nucleolar chromatin-remodelling complex NoRC to 150-250 nucleotide RNAs (pRNA) that originate from an RNA polymerase I promoter located in the intergenic spacer separating rDNA repeats. Here, we show that NoRC-associated pRNA is transcribed from a sub-fraction of hypomethylated rRNA genes during mid S phase, acting in trans to inherit DNA methylation and transcriptional repression of late-replicating silent rD ...[more]

PMID: 20010804

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