QIP, a protein that converts duplex siRNA into single strands, is required for meiotic silencing by unpaired DNA

Genetics. 2010 Sep;186(1):119-26. doi: 10.1534/genetics.110.118273. Epub 2010 Jun 15.


RNA interference (RNAi) depends on the production of small RNA to regulate gene expression in eukaryotes. Two RNAi systems exist to control repetitive selfish elements in Neurospora crassa. Quelling targets transgenes during vegetative growth, whereas meiotic silencing by unpaired DNA (MSUD) silences unpaired genes during meiosis. The two mechanisms require common RNAi proteins, such as RNA-directed RNA polymerases, Dicers, and Argonaute slicers. We have previously demonstrated that, while Quelling depends on the redundant dicer activity of DCL-1 and DCL-2, only DCL-1 is required for MSUD. Here, we show that QDE-2-interacting protein (QIP), an exonuclease that is important for the production of single-stranded siRNA during Quelling, is also required for MSUD. QIP is crucial for sexual development and is shown to colocalize with other MSUD proteins in the perinuclear region.

Publication types

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

MeSH terms

  • Cell Nucleus / metabolism
  • DNA, Single-Stranded / genetics*
  • Exonucleases / genetics
  • Exonucleases / metabolism*
  • Gene Expression Regulation, Fungal
  • Gene Silencing*
  • Homozygote
  • Meiosis / genetics*
  • Neurospora crassa / cytology
  • Neurospora crassa / enzymology
  • Neurospora crassa / genetics*
  • Neurospora crassa / growth & development
  • Protein Transport
  • RNA, Double-Stranded / metabolism*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism*


  • DNA, Single-Stranded
  • RNA, Double-Stranded
  • RNA, Small Interfering
  • Exonucleases