May 20, 2002

Post-transcriptional gene silencing (PTGS), which was initially considered a bizarre phenomenon limited to petunias and a few other plant species, is now one of the hottest topics in molecular biology (1). In the last few years, it has become clear that PTGS occurs in both plants and animals and has roles in viral defense and transposon silencing mechanisms. Perhaps most exciting, however, is the emerging use of PTGS and, in particular, RNA interference (RNAi) — PTGS initiated by the introduction of double-stranded RNA (dsRNA) — as a tool to knock out expression of specific genes in a variety of organisms (reviewed in 1-3).

How was RNAi discovered? How does it work? Perhaps more importantly, how can it be harnessed for functional genomics experiments? This article will briefly answer these questions and provide you with resources to find in depth information on PTGS and RNAi research.