The 2007 Nobel Prize in Physiology or Medicine goes Americans Mario Capecchi, Oliver Smithies and Briton Martin Evans won the 2007 Nobel Prize in medicine on Monday for their discoveries of principles for introducing specific gene modifications in mice by the use of embryonic stem cells.

This morning, Mario R. Capecchi, Martin J. Evans and Oliver Smithies were jointly awarded the Nobel Prize in Physiology or Medicine for their discoveries of “principles for introducing specific gene modifications in mice by the use of embryonic stem cells.”

The technology for homologous recombination in embryonic stem cells permits specific targeting of genes for disruption or modification in the resulting animal. Known as transgenic gene “knockouts” (and more recently, “knock-ins”), the methodology has allowed the study of specific processes in normal development, adult physiology, and numerous diseases. According to the Nobel press release, over 10,000 gene knockout mouse strains are now available, representing the manipulation of half of the total genes in mice.

The process, known as gene targeting, has been used to help study such diseases as cystic fibrosis, heart disease, diabetes and cancer.

In its citation, the award committee said that the use of gene targeting has shed light on embryonic development, aging and disease.

The medicine prize was the first of the six prestigious awards to be announced this year. The others are chemistry, physics, literature, peace and economics.

The prizes are handed out every year on Dec. 10, the anniversary of award founder Alfred Nobel’s death in 1896.

With gene targeting it is now possible to produce almost any type of DNA modification in the mouse genome, allowing scientists to establish the roles of individual genes in health and disease. Gene targeting has already produced more than five hundred different mouse models of human disorders, including cardiovascular and neuro-degenerative diseases, diabetes and cancer.