Illustrated information

The Nobel Prize in Physiology or Medicine 2006

The Nobel Assembly at Karolinska Institutet has awarded the Nobel Prize in Physiology or Medicine for 2006 jointly to Andrew Fire and Craig Mello for their discovery of RNA interference – gene silencing by double-stranded RNA.

RNA interference is a fundamental mechanism for controlling the flow of genetic information in cells.

Andrew Fire
Born 1959. Stanford University School of Medicine, Stanford, California, USA.

Craig Mello
Born 1960. University of Massachusetts Medical School, Worchester, Massachusetts, USA.

The central dogma

The genetic information in double-stranded DNA is transcribed into single-stranded messenger RNA (mRNA) in the cell nucleus and subsequently translated into protein in the cytoplasm.

Illustration: Annika Röhl and Bengt Gullbing. © The Nobel Committee for Physiology or Medicine at Karolinska Institutet

RNAi in the cell

Several processes generate double-stranded RNA.

RNA interference, RNAi

Double-stranded RNA triggers gene silencing.

Key experiments

Gene silencing

Fire and Mello injected RNA corresponding to a gene important for muscle function in the worm C. elegans.
Single-stranded RNA (sense or antisense) had no effect. But double-stranded RNA caused the worm to twitch in a similar way to worms that lack a functional gene for the muscle protein.

Loss of target mRNA

Fire and Mello injected RNA (mex-3 RNA) into the gonads of the worm C. elegans and studied the effect on the corresponding mRNA.

They found that double-stranded RNA, but not single-stranded RNA, eliminated the target mRNA.

RNA-based therapy – future and opportunities

Illustration of RNA-based therapy — Illustration: Annika Röhl and Bengt Gullbing. © The Nobel Committee for Physiology or Medicine at Karolinska Institutet

Credits and References for the 2006 Nobel Poster for Physiology or Medicine

Scientific Advisors, Professors at Karolinska Institutet:
Bertil Daneholt, Molecular Genetics, Chair of the Nobel Assembly
Göran K. Hansson, Medicine, Chair of the Nobel Committee
Hans Jörnvall, Physiological Chemistry, Secretary of the Nobel Assembly
Nils-Göran Larsson, Genetics

Illustrations and Layout: Annika Röhl, Bengt Gullbing

Web adapted version: Nobelprize.org