A genetic link between co-suppression and RNA interference in C. elegans.
Originally discovered in plants, the phenomenon of co-suppression by transgenic DNA has since been observed in many organisms from fungi to animals: introduction of transgenic copies of a gene results in reduced expression of the transgene as well as the endogenous gene. The effect depends on sequence identity between transgene and endogenous gene. Some cases of co-suppression resemble RNA interference (the experimental silencing of genes by the introduction of double-stranded RNA), as RNA seems to be both an important initiator and a target in these processes. Here we show that co-suppression in Caenorhabditis elegans is also probably mediated by RNA molecules. Both RNA interference and co-suppression have been implicated in the silencing of transposons. We now report that mutants of C. elegans that are defective in transposon silencing and RNA interference (mut-2, mut-7, mut-8 and mut-9) are in addition resistant to co-suppression. This indicates that RNA interference and co-suppression in C. elegans may be mediated at least in part by the same molecular machinery, possibly through RNA-guided degradation of messenger RNA molecules.
Ketting
R F
RF
Division of Molecular Biology, The Netherlands Cancer Institute, Centre for Biomedical Genetics, Amsterdam.
Plasterk
R H
RH
D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D004251:DNA Transposable Elements; D020868:Gene Silencing; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics; D009154:Mutation; D012330:RNA, Double-Stranded / Q000235:genetics / Q000502:physiology*; D018510:RNA, Helminth / Q000502:physiology*; D014162:Transfection
D029742:Caenorhabditis elegans Proteins; D004251:DNA Transposable Elements; D015801:Helminth Proteins; D012330:RNA, Double-Stranded; D018510:RNA, Helminth; C122185:rde-1 protein, C elegans