Thursday, October 16, 2008

From Jellyfish to Plants to Everything Alive: How a Magic Marker Altered Bioscience


[Source; Deb Daun, BIO5] - In a fortunate stroke of collaboration, a University of Arizona scientist has helped transform the Nobel-prize winning idea of marking cells with the bright green glow of a jellyfish into a basic tool of modern bioscience.

Plant Sciences Professor and BIO5 member David Galbraith, PhD, said today that he felt a personal attachment to the Nobel Prize given on Wednesday to Martin Chalfie and two others. The prize honored Chalfie’s paper in 1994 that showed how to use the jellyfish’s glow—caused by a Green Fluorescent Protein, or GFP, gene in its DNA—to mark a worm’s nerve cells.

With days of the publication of that paper, Galbraith, working in Arizona, was struck by an idea. That marker could become a much larger breakthrough for researchers trying to study cells in organs where individual cells were difficult, often impossible, to separate out and analyze.

”I read the jellyfish paper, and right away I thought, we should put that to use in plant cells,” Galbraith said.

Galbraith asked Chalfie to help him put the GFP gene to immediate use. Chalfie sent him samples of the DNA that encodes the green fluorescence, and some encouragement, and 14 years later the Nobel Prize has recognized both the initial breakthrough and the expanding applications that Galbraith was among the first to envision.

The discovery altered the way bioscience is conducted, Galbraith said, because GFP has proven effective in marking cells that had been all but impossible to study in the live tissues of organisms from bacteria to mice to other plants and animals used as models.

That crucial step—a simple way to label living cells with a fluorescent marker—now lets researchers in medicine, agriculture and basic cell biology examine the function of cells in any living organism. Since 1980, Galbraith says, he had been looking for a technique to label plant cells according to their function, where marking was more difficult than in animal cells.

”We engineered the Green Fluorescent Protein into plants so that it was produced only in specific cells,” Galbraith says. ”We have been working with that technique ever since that time, to make it possible to do cell sorting to isolate these different cells. Using our methods, we now can describe all of the genes that are active within any cell type within virtually any organism. Without the discovery of GFP, none of this would have been possible.”

Along with Chalfie, a biological sciences professor at Columbia University, the other co-winners of the 2008 Nobel Prize were Osamu Shimomura, of the Marine Biological Laboratory in Woods Hole, Mass., and Boston University Medical School, and Roger Y. Tsien, 56, a professor of pharmacology at the University of California, San Diego.

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