American scientists get medicine Nobel for finding microRNA

Two American scientists were awarded the Nobel Prize in physiology or medicine for their discovery of a fundamental principle governing how gene activity is regulated.

Victor Ambros and Gary Ruvkun will share the 11 million-krona ($1.1 million) award, the Nobel Assembly at Karolinska Institutet in Stockholm said in a statement Monday.

By studying a 1 millimeter-long roundworm, C. elegans, they discovered microRNA, a class of tiny RNA molecules that control gene activity in different kinds of cells. This allows muscle cells, intestinal cells and nerve cells, for example, to perform their specialized functions in the body.

Although all cell types have identical genetic information stored in their DNA, microRNA ensures that only the correct set of genes is active in each specific kind of cell.

“Gene regulation by microRNA, first revealed by Ambros and Ruvkun, has been at work for hundreds of millions of years,” the Nobel Assembly said in a statement. “This mechanism has enabled the evolution of increasingly complex organisms.”

Ambros, 70, is from Hanover, New Hampshire, and affiliated with the University of Massachusetts Medical School, while Ruvkun, 72, who was born in California, is associated with Massachusetts General Hospital in Boston and Harvard Medical School.

Last year’s medicine Nobel celebrated research that laid the groundwork for some of the best-selling medicines of all time: the messenger-RNA vaccines against COVID-19.

Other recipients in the field of medicine have been awarded for the discoveries of various viruses, for the development of magnetic resonance imaging and in vitro fertilization. Just over 100 years ago, the award went to Frederick G. Banting and John Macleod for the discovery of insulin.

Annual prizes for achievements in physics, chemistry, medicine, literature and peace were established in the will of Alfred Nobel, the Swedish inventor of dynamite, who died in 1896. A prize in economic sciences was added by Sweden’s central bank in 1968.

The laureates are announced through Oct. 14 in Stockholm, with the exception of the peace prize, whose recipients are selected by the Norwegian Nobel Committee in Oslo.