CAMBRIDGE, Mass. (June 6, 2007) -- Embryonic stem cells are unique because they can develop into virtually any kind of tissue type, an attribute called pluripotency. Somatic cell nuclear transfer (therapeutic cloning) offers the hope of one day creating customized embryonic stem cells with a patients own DNA. Here, an individuals DNA would be placed into an egg, resulting in a blastocyst that houses a supply of stem cells. But to access these cells, researchers must destroy a viable embryo.

Now, scientists at Whitehead Institute have demonstrated that embryonic stem cells can be created without eggs. By genetically manipulating mature skin cells taken from a mouse, the scientists have transformed these cells back into a pluripotent state, one that appears identical to an embryonic stem cell in every way. No eggs were used, and no embryos destroyed.

These reprogrammed cells, by all criteria that we can apply, are indistinguishable from embryonic stem cells, says Whitehead Member and MIT professor of biology Rudolf Jaenisch, senior author of the paper that will appear online June 6 in Nature.

Whats more, these reprogrammed skin cells can give rise to live mice, contributing to every kind of tissue type, and can even be transmitted via germ cells (sperm or eggs) to succeeding generations. Germline transmission is the final and definitive proof that these cells can do anything a traditionally derived embryonic stem cell can do, adds Jaenisch.

Two additional papers report similar findings. The first, by Shinya Yamanaka of Kyoto University, will be published in the same issue of Nature. The second, from Konrad Hochedlinger, formerly of the Jaenisch lab and now at Center for Regenerative Medicine at Massachusetts General Hospital and Harvard Stem Cell Institute, will appear in the inaugural issue of the journal Cell Stem Cells. Additionally, another paper in Nature from Kevin Eggan, also of the Harvard Stem Cell Institute an
'"/>

Contact: David Cameron
newsroom@wi.mit.edu
617-324-0460
Whitehead Institute for Biomedical Research
6-Jun-2007