Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-19734 - Argonaute Surveillance and Dicer-Independent priRNAs TriggerRNAi and Heterochromatin Formation
Released on 23 February 2010, last updated on 27 June 2012
The assembly of fission yeast pericentromeric heterochromatin and generation of small interfering RNAs (siRNAs) from noncoding centromeric transcripts are mutually dependent processes. How this interdependent positive feedback loop is first triggered is a fundamental unanswered question. Here we show that two distinct Argonaute (Ago1)-dependent pathways mediate small RNA generation. RNA-dependent RNA polymerase complex (RDRC) and Dicer act on specific noncoding RNAs to generate siRNAs by a mechanism that requires the slicer activity of Ago1 but is independent of pre-existing heterochromatin. In the absence of RDRC or Dicer, a distinct class of small RNAs, called primal small RNAs (priRNAs), associate with Ago1. priRNAs are degradation products of abundant transcripts, which bind to Ago1 and target antisense transcripts that result from bidirectional transcription of DNA repeats. Our results suggest that a transcriptome surveillance mechanism based on the random association of RNA degradation products with Argonaute triggers siRNA amplification and heterochromatin assembly within DNA repeats. small RNA profiling in wild type S. pombe cells and in 12 mutant cells
RNA-seq of non coding RNA
Danesh Moazed, Mario Halic
Dicer-independent primal RNAs trigger RNAi and heterochromatin formation. Halic M, Moazed D. , PMID:20178743