The Nobel Prizes in science will be announced — one prize per day — between now and Wednesday. Today, the winners of the prize for physiology or medicine were announced. John Gurdon and Shinya Yamanaka will share the award for work related to cloning and our ability to manipulate the functioning of stem cells.
What's interesting here is that the research these two men are winning the Nobel for happened nearly a generation apart. Gurdon's work was crucial to the development of cloning. You'll recall that some embryonic stem cells can grow up to be anything, any part of animal's living tissue. Differentiated stem cells, in contrast, are destined for a specific job — for instance, they could grow into skin cells, or nerve cells, but not both. In 1952, other scientists had concluded that you could take genetic material from a very early frog embryo, inject it into the egg cell of another frog, and get that to grow into a living animal — a clone. But those researchers thought this process would only work up to a point. They didn't think you could clone an adult, or even an older fetus. Gurdon proved them wrong. In a series of experiments published between 1958, 1962, 1966, he worked with older and older donor cells, and produced more developed clones — eventually growing fully adult, fertile frogs from cells taken from the intestines of tadpoles.
Yamanaka, meanwhile, did his research in the early part of the 21st century, developing the methods that allow us to trick grown-up, set-in-their-ways cells into behaving more like embryonic stem cells. Yamanaka's work is linked to Gurdon's because it explains why Gurdon (and researchers after him) were able to successfully clone adult animals from cells that had fully differentiated.
The research history here is a little hard to follow, especially with Gurdon's work. The description of his findings I have here is what I've been able to piece together from several different sources, citing several different dates and specific achievements. To help cut through some of the confusion, here's a couple of links where you can get a good, reasonably detailed idea of what this research is, and why it matters:
• This article on the history of cloning from the Proceedings of the National Academy of Sciences is easily readable and interesting, especially if your awareness of this topic begins with Dolly the Sheep.
• In 2009, Gurdon and Yamanaka won the Albert Lasker Basic Medical Research Award. That organization has a good explanation of how both men did their experiments and how their work ties together.