Onorati MC, Arancio W, Cavalieri V, Ingrassia AMR, Pavesi G, Corona DFV. Trans-Reactivation: A New Epigenetic Phenomenon Underlying Transcriptional Reactivation of Silenced Genes.
PLoS Genet 2015;
11:e1005444. [PMID:
26292210 PMCID:
PMC4546373 DOI:
10.1371/journal.pgen.1005444]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 07/15/2015] [Indexed: 12/04/2022] Open
Abstract
In order to study the role played by cellular RNA pools produced by homologous genomic loci in defining the transcriptional state of a silenced gene, we tested the effect of non-functional alleles of the white gene in the presence of a functional copy of white, silenced by heterochromatin. We found that non-functional alleles of white, unable to produce a coding transcript, could reactivate in trans the expression of a wild type copy of the same gene silenced by heterochromatin. This new epigenetic phenomenon of transcriptional trans-reactivation is heritable, relies on the presence of homologous RNA’s and is affected by mutations in genes involved in post-transcriptional gene silencing. Our data suggest a general new unexpected level of gene expression control mediated by homologous RNA molecules in the context of heterochromatic genes.
We discovered a new epigenetic phenomenon we called trans-reactivation. We found that genes, unable to produce a functional coding transcript, but with the potential of transcribing other RNA’s within their gene body, strongly reactivate the transcription of a wildtype copy of the same gene silenced by heterochomatin. This new epigenetic phenomenon is heritable, relies on the presence of diffusible RNAs able to carry and transfer epigenetic information and is affected by mutations in genes involved in Post-Transcriptional Gene Silencing. Our data strongly suggest that homologous non-coding RNA can reactivate the expression of genes silenced by heterochromatin, thus defining a new unpredicted level of gene expression control in the context of heterochromatic genes.
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