Greco, Guasch and Li compared the cloning efficiency of adult skin stem cells with that of more differentiated skin cells and also with cumulus cells the cells that surround a developing oocyte and have traditionally been the preferred cell type for nuclear transfer. The stem cells gave the best efficiency, yielding 19 pups, nine of which grew up into normal, healthy, breeding adult mice.
This is not the first time scientists have tried to use adult stem cells to clone mice. Experiments using adult hematopoetic stem cells the cells in the bone marrow that all blood cells are derived from were reported last year. But their conclusions were confusing, says Mombaerts, and there are no reports on using adult stem cells for reproducible cloning of mice that survive until adulthood. By using cells from the same mouse and performing the experiments on the two successive days, the Rockefeller scientists could directly compare adult stem cells with other cell types.
Nuclear transfer can also be used to make embryonic stem cell lines, a process which can be done in a tissue culture dish and which is simpler and more efficient than generating a cloned mouse. Although this procedure has not yet successfully generated human embryonic stem cell lines, once technological hurdles are overcome, it may be possible in the future to use a patient's skin stem cells to tailor make embryonic stem cell lines, circumventing the problem of immune rejection.
Such stem cells might also be used to study a variety of different diseases, for which patient tissue is often hard to come by.
"There are many diseases, such as liver, pancreatic and neurodegenerative disorders where researchers are only able to obtain affected tissue from autopsies," says Fuchs.
If on the other hand, scientists ar
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Contact: Kristine Kelly
kkelly@rockefeller.edu
212-327-7146
Rockefeller University
12-Feb-2007