The silence of the genes.

About two years ago, it was recognized that introduction of double-stranded RNA (dsRNA) had a potent effect on gene expression, in particular on mRNA stability. Since then, this process has been found to occur in many different organisms, and to bear a strong resemblance to a previously recognized process in plants, called cosuppression. Both genetic and biochemical studies have started to unravel the mysteries of RNA interference: genes involved in this process are being identified and in vitro studies are giving the first hints of what is happening to both the dsRNA and the affected mRNA molecules after the introduction of the dsRNA.