Molecular and Cellular Biology Laboratory, The Salk Institute, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Repeated DNA elements and region-specific protein modifications combine within chromosomes to form a transcriptionally silent chromatin structure called heterochromatin. Recent work in the fission yeast Schizosaccharomyces pombe reveals that RNA is also an integral component of silent heterochromatin, providing a new perspective on how heterochromatin is organized and maintained in eukaryotic cells.