The piRNA pathway in flies: highlights and future directions

Curr Opin Genet Dev. 2013 Feb;23(1):44-52. doi: 10.1016/j.gde.2012.12.003. Epub 2013 Jan 11.


Piwi proteins, together with their bound Piwi-interacting RNAs, constitute an evolutionarily conserved, germline-specific innate immune system. The piRNA pathway is one of the key mechanisms for silencing transposable elements in the germline, thereby preserving genome integrity between generations. Recent work from several groups has significantly advanced our understanding of how piRNAs arise from discrete genomic loci, termed piRNA clusters, and how these Piwi-piRNA complexes enforce transposon silencing. Here, we discuss these recent findings, as well as highlight some aspects of piRNA biology that continue to escape our understanding.

Publication types

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

MeSH terms

  • Animals
  • DNA Transposable Elements
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / growth & development
  • Female
  • Gene Silencing
  • Genetic Loci
  • Germ Cells / metabolism
  • Ovary / metabolism
  • RNA, Small Interfering / genetics*
  • RNA, Small Interfering / metabolism
  • Signal Transduction*


  • DNA Transposable Elements
  • Drosophila Proteins
  • RNA, Small Interfering