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Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells


RNA interference (RNAi) is the process of sequence-specific, post-transcriptional gene silencing in animals and plants, initiated by double-stranded RNA (dsRNA) that is homologous in sequence to the silenced gene1,2,3,4. The mediators of sequence-specific messenger RNA degradation are 21- and 22-nucleotide small interfering RNAs (siRNAs) generated by ribonuclease III cleavage from longer dsRNAs5,6,7,8,9. Here we show that 21-nucleotide siRNA duplexes specifically suppress expression of endogenous and heterologous genes in different mammalian cell lines, including human embryonic kidney (293) and HeLa cells. Therefore, 21-nucleotide siRNA duplexes provide a new tool for studying gene function in mammalian cells and may eventually be used as gene-specific therapeutics.

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Figure 1: Reporter constructs and siRNA duplexes.
Figure 2: RNA interference by siRNA duplexes.
Figure 3: Effects of 21-nucleotide siRNAs, 50-bp, and 500-bp dsRNAs on luciferase expression in HeLa cells.
Figure 4: Silencing of nuclear envelope proteins lamin A/C in HeLa cells.

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We thank J. Martinez, J. Ludwig and D. Bartel for comments on the manuscript; L. Fredel for help with image processing; H.-J. Dehne for technical assistance; F. Döring, R. Nehring, D. Ingelfinger and C. Schneider for supplying cell lines; A. Dickmanns for the gift of the plasmid pAD3; and R. Lührmann for support. This work was funded by a Biofuture grant of the Bundesministerium für Bildung und Forschung.

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Correspondence to Thomas Tuschl.

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Elbashir, S., Harborth, J., Lendeckel, W. et al. Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells. Nature 411, 494–498 (2001).

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