Embryonic stem cells have received the most press for their potential to generate healthy cells and tissues that could replace damaged or diseased organs. “Scientists are well aware that tissue derived from someone else’s embryonic stem cells would be recognized as foreign and rejected by the patient,” says senior co-author Elaine Fuchs, the Rebecca C. Lancefield Professor at Rockefeller and a Howard Hughes Medical Institute investigator. “This is one of the reasons why scientists have focused so much attention toward using nuclear transfer, which would allow us to use adult stem cells from the same patient rather than those harvested from an unrelated embryo.” Fuchs and her colleagues tested the method in adult stem cells taken from the skin of mice.
Using purification methods developed in Fuchs’s Laboratory of Mammalian Cell Biology and Development, postdocs Valentina Greco and Géraldine Guasch isolated stem cells from the mice’s hair follicles. They gave these stem cells to Jinsong Li, a postdoc in Rockefeller’s Laboratory of Developmental Biology and Neurogenetics headed by senior co-author Peter Mombaerts. To execute the nuclear transfer procedure, Li took unfertilized mouse oocytes and replaced the nucleus of each oocyte with a nucleus from the adult skin stem cells.
A main hurdle in nuclear transfer with adult cells has been its efficiency – out of a hundred attempts, only a handful may succeed – with reported success rates never reaching into double digits. “The efficiency of nuclear transfer is very low,” says Li. “Using purified adult skin stem cells as our source of nuclei, we have found that higher nuclear transfer efficiencies can be achieved.”