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Interacting endogenous and exogenous RNAi pathways in Caenorhabditis elegans.
RNA (2006)
  • Rosalind C. Lee
  • Christopher M. Hammell
  • Victor R. Ambros
C. elegans contains numerous small RNAs of ~21-24 nt in length. The microRNAs (miRNAs) are small noncoding RNAs produced by DCR-1- and ALG-dependent processing of self-complementary hairpin transcripts. Endogenous small interfering RNAs (endo-siRNAs), associated with ongoing silencing of protein-coding genes in normal worms, are produced by mechanisms that involve DCR-1 but, unlike miRNAs, also involve RDE-2, RDE-3, RDE-4, RRF-1, and RRF-3. The tiny noncoding (tncRNAs) are similar to endo-siRNAs in their biogenesis except that they are derived from noncoding sequences. These endo-siRNA- and tncRNA-based endogenous RNAi pathways involve some components, including DCR-1 and RDE-4, that are shared with exogenous RNAi, and some components, including RRF-3 and ERI-1, that are specific to endogenous RNAi. rrf-3 and eri-1 mutants are enhanced for some silencing processes and defective for others, suggesting cross-regulatory interactions between RNAi pathways in C. elegans. Microarray expression profiling of RNAi-defective mutant worms further suggests diverse endogenous RNAi pathways for silencing different sets of genes.
Publication Date
April 1, 2006
Publisher Statement
Copyright 2006 by RNA Society. Publisher PDF posted as allowed by the publisher's author rights policy at
Citation Information
Rosalind C. Lee, Christopher M. Hammell and Victor R. Ambros. "Interacting endogenous and exogenous RNAi pathways in Caenorhabditis elegans." RNA Vol. 12 Iss. 4 (2006)
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