PIWI-interacting small RNAs: the vanguard of genome defence

Nat Rev Mol Cell Biol. 2011 Apr;12(4):246-58. doi: 10.1038/nrm3089.


PIWI-interacting RNAs (piRNAs) are a distinct class of small non-coding RNAs that form the piRNA-induced silencing complex (piRISC) in the germ line of many animal species. The piRISC protects the integrity of the genome from invasion by 'genomic parasites'--transposable elements--by silencing them. Owing to their limited expression in gonads and their sequence diversity, piRNAs have been the most mysterious class of small non-coding RNAs regulating RNA silencing. Now, much progress is being made into our understanding of their biogenesis and molecular functions, including the specific subcellular compartmentalization of the piRNA pathway in granular cytoplasmic bodies.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • DNA Transposable Elements / genetics
  • Genome / genetics*
  • Models, Genetic
  • Mutagenesis, Insertional
  • RNA Interference*
  • RNA, Small Interfering / genetics*
  • RNA, Small Interfering / metabolism
  • RNA, Small Untranslated / genetics*
  • RNA, Small Untranslated / metabolism


  • DNA Transposable Elements
  • RNA, Small Interfering
  • RNA, Small Untranslated