Andrew Fire and Craig Mello have won the Nobel prize in physiology or medicine for their discovery of RNA interference.

US molecular biologists Andrew Fire and Craig Mello have been awarded this year’s Nobel prize in physiology or medicine for their discovery of RNA interference (RNAi).

Fire, professor of genetics at Stanford University School of Medicine, and Mello, professor of molecular medicine at the University of Massachusetts Medical School, reported in 1998 that genes could be silenced by the mechanism of RNAi. 

The prize is well deserved, said Muhammad Sohail, a biochemist at the University of Oxford, UK, and editor of the Journal of RNAi and Gene Silencing: ’These are the two pioneers in the field ... People will be very happy that this has been recognised so early.’ About five years ago there were only 70 or 80 papers in the field, said Sohail: ’Now there’s 70 or 80 every week!’

RNAi is activated when RNA molecules occur as double-stranded pairs in the cell. Double-stranded RNA activates biochemical machinery that degrades messenger RNA molecules with a genetic code identical to that of the double-stranded RNA. (Messenger RNA is transcribed from a DNA template in the nucleus, and exported out of the nucleus where it becomes a template for protein synthesis in the cytoplasm.)

RNAi is a natural regulator of gene expression, and guards against viral infection. It is used in the lab to study gene function, and many researchers - including Fire and Mello - believe it holds therapeutic promise.