British clone pioneer Professor Sir John Gurdon has been awarded the Nobel Prize for Medicine which he shares with a leading Japanese stem cell scientist.
He and Professor Shinya Yamanaka, from Kyoto University, won the prize for their work on reprogramming ordinary cells into immature stem cells.
In 1962, while still a graduate student, Sir John made a pivotal early discovery that set the stage for future cloning research.
He successfully cloned the South African frog Xenopus from a tadpole's intestinal cell. By transplanting the cell nucleus into an empty Xenopus egg cell, he produced a frog that was genetically identical to the original tadpole.
The result sent shockwaves through the scientific community, proving that the genetic code in the cell nucleus contained all the information needed to create a new organism.
More than four decades later, in 2006, Prof Yamanaka showed how mature cells in mice could be made to revert to a youthful embryonic state. Like stem cells from embryos, the "induced pluripotent stem cells", or iPSCs, had the potential to develop into any kind of cell in the body.
In a statement the Nobel Assembly at Stockholm's Karolinska Institute in Sweden said the scientists' achievements had "revolutionised our understanding of how cells and organisms develop". The award is technically for "physiology or medicine".
Sir John was educated at Eton College and originally applied to Christ Church, Oxford, to study classics. After he was accepted he switched to zoology and went on to conduct his groundbreaking tadpole experiments.
He is now a group leader at the Wellcome Trust/CRUK Gurdon Institute in Cambridge. Both scientists will share the prize money of eight million Swedish kronur (£750,000).
Responding to the announcement, Sir Paul Nurse, president of the Royal Society, said: "I was delighted to learn that John Gurdon shares this year's Nobel Prize for Physiology or Medicine with Shinya Yamanaka. John's work has changed the way we understand how cells in the body become specialised, paving the way for important developments in the diagnosis and treatment of disease."