The genome encodes thousands of small RNAs that interact with PIWI proteins; these PIWI-interacting RNAs (piRNAs) mediate silencing of transposable elements and thereby protect the genome. New insights are being gained into the formation and functions of piRNAs, and where they exert their action in the cell.
- Mikiko C. Siomi
- Kaoru Sato
- Alexei A. Aravin
