for National Geographic News
Three scientists have won the 2007 Nobel Prize in Physiology or Medicine for pioneering methods that allow scientists to "knock out" specific genes in mice, a crucial technique for studying genetically caused human diseases.
The Nobel Assembly at the Karolinska Institute in Stockholm, Sweden, announced yesterday that U.S. researchers Mario Capecchi and Oliver Smithies will share the prize with British geneticist Sir Martin Evans. The award is worth 10 million Swedish kronors (about 1.5 million U.S. dollars).
The trio received the honor for developing methods to selectively target genes in mice using embryonic stem cells, the award committee announced.
The research is often used to create "knockout" mice missing one or more genes, allowing scientists to determine how specific genes cause disease, the committee said.
This work has "has revolutionized life science and plays a key role in the development of medical therapy," the committee added.
Stem Cell Technique
Evans, of Cardiff University in Wales, identified and isolated stem cells while working with mice. These cells, found in animal embryos, are able to develop into any kind of specialized body tissue, such as those of the heart or skin.
Evans discovered that lab-cultured stem cells could be altered and injected into mouse embryos to produce genetically modified rodents.
Capecchi and Smithies, who are Italian and British-born, respectively, developed a method of altering genes by introducing short sequences of altered DNA into cultured cells.
The technique allows scientists to target individual genes with extreme precision to produce a particular genetic mutation.
The combined work of the three scientists makes it possible to breed mice with tailored genetic mutations that would be passed down through generations.
Steve Brown, director of the Medical Research Council's Mammalian Genetics Unit in Harwell, England, said the research techniques developed by the prize winners have allowed scientists to unravel how genes work in mammals.
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