All they had to do, the scientists said, was add four genes. The genes reprogrammed the chromosomes of the skin cells, making the cells into blank slates that should be able to turn into any of the 220 cell types of the human body, be it heart, brain, blood or bone. Until now, the only way to get such human universal cells was to pluck them from a human embryo several days after fertilization, destroying the embryo in the process.
The new discovery is published online in Cell, in a paper by Shinya Yamanaka of Kyoto University and the Gladstone Institute of Cardiovascular Disease in San Francisco, and in Science, in a paper by James A. Thomson and his colleagues at the University of Wisconsin.
The need to destroy embryos has made stem cell research one of the most divisive issues in American politics, pitting President Bush against prominent Republicans like Nancy Reagan, and patient advocates who hoped that stem cells could cure diseases like Alzheimer’s. The new studies could defuse the issue as a presidential election nears. Link