Two Americans and a U.S.-based Japanese scientist won the Nobel Prize in chemistry on Wednesday for research on a glowing jellyfish protein that revolutionized the ability to study disease and normal development in living organisms.
Japan's Osamu Shimomura and Americans Martin Chalfie and Roger Tsien shared the prize for discovering and developing green fluorescent protein, or GFP, the Royal Swedish Academy of Sciences said.
Chalfie said he slept through the Nobel committee's phone calls early Wednesday and only found out about the prize when he checked the Nobel Web site to see who had won.
"It's not something out of the blue, but you never know when it's going to come or if it's going to come so it's always a big surprise when it actually happens," Chalfie said in New York.
Shimomura, 80, works at the Marine Biological Laboratory in Woods Hole, Mass., and the Boston University Medical School.
Chalfie, 61, is a professor at Columbia University in New York, while Tsien, 56, is a professor at the University of California, San Diego.
Speaking in a teleconference with reporters, Tsien said he was surprised to receive the award.
"I feel a bit like a deer caught in the headlights," said Tsien, who also is an investigator with the Howard Hughes Medical Institute. "Fundamentally, I'm no smarter today than I was yesterday."
As a child, Tsien was dazzled by colors and that later helped him in his career.
"I like pretty colors ... and this was a good opportunity," said Tsien, explaining how he got into GFP research.
Shimomura told Japanese broadcaster NHK that he, too, was surprised, "because I was rumored as a potential candidate for the Nobel Prize in physiology or medicine, but not in chemistry."
The trio will split the 10 million kronor (US$1.4 million) award.
Researchers worldwide now use GFP to track such processes as the development of brain cells, the growth of tumors and the spread of cancer cells.
It has let them study nerve cell damage from Alzheimer's disease and see how insulin-producing beta cells arise in the pancreas of a growing embryo, for example.
The academy compared the impact of GFP on science to the invention of the microscope. For the past decade, the academy said, the protein has been "a guiding star for biochemists, biologists, medical scientists and other researchers."
When exposed to ultraviolet light, the protein glows green. So it can act as a tracer to expose the movements of other, invisible proteins it is attached to as they go about their business.
It can also be used to mark particular cells in a tissue and show when and where particular genes turn on and off.
Tsien developed GFP-like proteins that produced a variety of colors so that multiple proteins or cells can be followed simultaneously.
"In one spectacular experiment, researchers succeeded in tagging different nerve cells in the brain of a mouse with a kaleidoscope of colors," the Nobel citation said. The experiment was called the "brainbow."
Shimomura and a colleague found GFP in material they extracted from about 10,000 jellyfish they had recovered off the coast of the state of Washington in the United States. They reported in 1962 that it glowed bright green under ultraviolet light.
Some 30 years later, Chalfie showed that the GFP gene could make individual nerve cells in a tiny worm glow bright green. Tsien later extended the scientific palette to a variety of colors.
"This is a technology that has literally transformed medical research," said Dr. John Frangioni, an associate professor of medicine and radiology at Harvard Medical School. "For the first time, scientists could study both genes and proteins in living cells and in living animals."
Tsien's lab initially developed fluorescent GFP-like proteins in blue and yellow and later expanded his color palette to include oranges, reds and purples. Tsien wants to push the spectrum even more to include longer wavelengths.
In a news release issued by his university, Tsien said he had set his sights on imaging and treating cancer.
"I've always wanted to do something clinically relevant in my career, if possible, and cancer is the ultimate challenge," he said.
Gunnar von Heijne, the chairman of the chemistry prize committee, demonstrated the award-winning research to reporters by shining ultraviolet light on a tube with E. coli bacteria containing GFP. The tube glowed in a green fluorescent light.
Von Heijne said that kind of experiment "gets scientists' hearts beating three times faster than normal."
The winners of the Nobel Prizes in medicine and physics were presented earlier this week. The prizes for literature, peace and economics are due to be announced Thursday, Friday and Monday.
So far, three Americans, three Japanese, two French and one German researcher have won Nobel Prizes this year.
The awards include the money, a diploma and an invitation to the prize ceremonies in Stockholm and Oslo on Dec. 10, the anniversary of prize founder Alfred Nobel's death in 1896.