UNRAVELING TELOMERES: The 2009 Nobel Prize in Physiology or Medicine recognizes work going back nearly three decades on the role of genetic code that marks the end of chromosomes. Image: THE NOBEL COMMITTEE/ANNIKA ROHL
The 2009 Nobel Prize in Physiology or Medicine will go to three Americans who discovered telomeres, the genetic code that protects the ends of chromosomes, and telomerase, the enzyme that assists in this process, findings that are important in the study of cancer, aging and stem cells.
Announced this morning in Stockholm, the three geneticists—Elizabeth Blackburn, a professor of biology and physiology at the University of California, San Francisco, Carol Greider, a professor in the department of molecular biology and genetics at Johns Hopkins University School of Medicine in Baltimore, and Jack Szostak, a professor of genetics at Massachusetts General Hospital in Boston, who are all previous Scientific American authors—will split the award of 10 million Swedish kronor (about $1.4 million), along with the prestige and honor.
The work for which they received the award illuminated key aspects of the DNA replication process. As genetic material is copied from the chromosome during cell division, the whole DNA strand must be duplicated from end to end, otherwise, portions of genetic information will be lost. Until the 1980s, it was a mystery as to how the chromosomes could be reliably copied the whole way through without missing bits and pieces at the very end of each strand. Work completed by this year’s laureates demonstrated how, if parts of the end-cap telomeres were missing, DNA would eventually be shortened and cut off in the replication process.
Blackburn and Szostak, who had been studying the ends of chromosomes and minichromosomes respectively, met at a conference in 1980, after which they began collaborating. Two years later, they demonstrated in a paper published in Cell that the telomere sequence could be isolated, inserted into another organism and still serve the same function. Working with Blackburn, Greider helped in 1989 to identify the RNA-based telomerase—the enzyme that creates the crucial telomeres—in a paper published in Nature. (Scientific American is part of the Nature Publishing Group.)
More at www.scientificamerican.com/article.cfm?id=nobel-prize-medicine-2009-genetics