The two will share the $1.2m Nobel prize for medicine, for work Gurdon began 50 years ago and Yamanaka capped with a 2006 experiment that transformed the field of "regenerative medicine" — the field of curing disease by regrowing healthy tissue.
"These groundbreaking discoveries have completely changed our view of the development and specialisation of cells," the Nobel Assembly at Stockholm’s Karolinska Institute said.
Stem cells produce all of the body’s tissue before developing into more complex structures that create skin, blood, nerves, muscle and bone cells. Researchers hope to one day use stem cells to replace damaged tissue in everything from spinal cord injuries to Parkinson’s disease.
Experts in the field once thought it was impossible to turn adult tissue back into stem cells, which meant that new stem cells could only be created by harvesting embryos — a practice that raised ethical qualms in some countries and also means that implanted cells might be rejected by the body.
In 1958, Gurdon was the first scientist to clone an animal, producing a healthy tadpole from the egg of a frog with DNA from another tadpole’s intestinal cell.
The experiment proved developed cells still carry the information needed to make every cell in the body, decades before other scientists made headlines around the world by cloning the first mammal, Dolly the sheep.
More than 40 years later, Yamanaka was able to produce mouse stem cells from adult mouse skin cells without embryo adoption , by inserting a few genes. His breakthrough effectively showed that the development that takes place in adult tissue could be reversed, turning adult cells back into cells that behave like embryos. The new stem cells are known as "induced pluripotency stem cells.”