The role of small non-coding RNAs in genome stability and chromatin organization.

Small non-coding RNAs make up much of the RNA content of a cell and have the potential to regulate gene expression on many different levels. Initial discoveries in the 1990s and early 21st century focused on determining mechanisms of post-transcriptional regulation mediated by small-interfering RNAs (siRNAs) and microRNAs (miRNAs). More recent research, however, has identified new classes of RNAs and new regulatory mechanisms, expanding the known regulatory potential of small non-coding RNAs to encompass chromatin regulation. In this Commentary, we provide an overview of these chromatin-related mechanisms and speculate on the extent to which they are conserved among eukaryotes.