A new approach to the inhibition of gene expression

The induction of a specific down-regulation in gene expression is an important research tool. Recently, several related processes including post-transcriptional gene silencing (PTGS) and RNA interference (RNAi) have been identified that generate sequence-specific inhibition of gene expression. Although the physiological function of PTGS and RNAi is still being elucidated, these pathways have been used to rapidly determine gene function. The recent observation of RNAi in mammalian cells extends the possible applications of these mechanisms.