title: QIP, a protein that converts duplex siRNA into single strands, is required for meiotic silencing by unpaired DNA.
abstract: 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.
authors.affiliation: Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Xiao
authors.forename: William G
authors.initials: WG
authors.lastname: Alexander
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Hammond
authors.forename: Erin C
authors.initials: EC
authors.lastname: Boone
authors.forename: Tony D
authors.initials: TD
authors.lastname: Perdue
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Pukkila
authors.forename: Patrick K T
authors.initials: PK
authors.lastname: Shiu
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000235:genetics*; D005092:Exonucleases / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D020868:Gene Silencing; D006720:Homozygote; D008540:Meiosis / Q000235:genetics*; D009492:Neurospora crassa / Q000166:cytology / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D021381:Protein Transport; D012330:RNA, Double-Stranded / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*
chemical_list: D004277:DNA, Single-Stranded; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering; D005092:Exonucleases