[RNA interference: towards a functional genomics in mammalian cells?]

The discovery of the induction of RNA degradation by double stranded RNA in C. elegans, "RNA interference", makes it possible to envision systematic studies of gene function in mammalian cells. Indeed, in spite of the existence in mammals of the interferon response to double stranded RNA, the introduction of small interfering RNA can induce a sequence specific inhibition of gene expression either through RNA degradation or by blocking translation. Although the inhibition is transient and usually not complete, strategies have been developed to achieve long term gene silencing. The issue of target specificity is still not completely clear and will probably constitute a limitation of this approach. However, because of the unprecedented ease with which large scale screens can be performed, RNA interference has already established itself as the tool of choice to initiate functional genomics in mammalian cells.