RNAi Extends Its Reach

Abstract
Genes are silenced when tiny regulatory RNAs bind to target messenger RNAs. But it is becoming clear that RNA interference goes beyond these interactions. In their perspective, Matzke and Matzke discuss recent work (Schramke and Allshire) that shows that the silencing pathway can induce heterochromatin formation in DNA that is normally euchromatic. The heterochromatin can spread laterally to silence nearby genes.