RNA interference (also called "RNA-mediated interference",
abbreviated RNAi) is a mechanism for RNA-guided regulation of gene
expression in which double-stranded ribonucleic acid inhibits the
expression of genes with complementary nucleotide sequences.
Conserved in most eukaryotic organisms, the RNAi pathway is thought
to have evolved as a form of innate immunity against viruses and also
plays a major role in regulating development and genome maintenance.
http://bioisolutions.blogspot.com/2007/11/rnai-discovery.html
Regards
Thomas
