title: RNA interference can target pre-mRNA: consequences for gene expression in a Caenorhabditis elegans operon.
abstract: In nematodes, flies, trypanosomes, and planarians, introduction of double-stranded RNA results in sequence-specific inactivation of gene function, a process termed RNA interference (RNAi). We demonstrate that RNAi against the Caenorhabditis elegans gene lir-1, which is part of the lir-1/lin-26 operon, induced phenotypes very different from a newly isolated lir-1 null mutation. Specifically, lir-1(RNAi) induced embryonic lethality reminiscent of moderately strong lin-26 alleles, whereas the lir-1 null mutant was viable. We show that the lir-1(RNAi) phenotypes resulted from a severe loss of lin-26 gene expression. In addition, we found that RNAi directed against lir-1 or lin-26 introns induced similar phenotypes, so we conclude that lir-1(RNAi) targets the lir-1/lin-26 pre-mRNA. This provides direct evidence that RNA interference can prevent gene expression by targeting nuclear transcripts. Our results highlight that caution may be necessary when interpreting RNA interference without the benefit of mutant alleles.
authors.affiliation: Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 67404 Illkirch Cedex, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Bosher
authors.forename: P
authors.initials: P
authors.lastname: Dufourcq
authors.forename: S
authors.initials: S
authors.lastname: Sookhareea
authors.forename: M
authors.initials: M
authors.lastname: Labouesse
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D017353:Gene Deletion; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics; D007438:Introns; D009687:Nuclear Proteins; D009876:Operon; D010641:Phenotype; D012322:RNA Precursors / Q000235:genetics*; D018510:RNA, Helminth / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics; D016335:Zinc Fingers
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; C119886:LIR-1 protein, C elegans; D009687:Nuclear Proteins; D012322:RNA Precursors; D018510:RNA, Helminth; D012333:RNA, Messenger; D014157:Transcription Factors; C090507:lin-26 protein, C elegans