PNAS | 2005 | Nuclear Transfer: Bringing in the Clones |
ntES | somatic cell nuclear transfer embryonic stem cell | 2004 |
ISSCR: International Society for Stem Cell Research
Nuclear Transfer -- Stem Cells or Somatic Cell Nuclear Transfer (SCNT) |
Thinkquest | 1928 | 1928 images | 1938 |
Nuclear transfer requires two cells, a donor cell and an oocyte, or egg cell. Research has proven that the egg cell works best if it is unfertilized, because it is more likely to accept the donor nucleus as its own. The egg cell must be enucleated. This eliminates the majority of its genetic information. The donor cell is then forced into the Gap Zero, or G0 cell stage, a dormant phase, in different ways depending on the technique. This dormant phase causes the cell to shut down but not die. In this state, the nucleus is ready to be accepted by the egg cell. The donor cell’s nucleus is then placed inside the egg cell, either through cell fusion or transplantion. The egg cell is then prompted to begin forming an embryo. When this happens, the embryo is then transplanted into a surrogate mother. If all is done correctly, occasionally a perfect replica of the donor animal will be born.
Each group of researchers has
its own specific technique.
The best known is the Roslin
technique, and
the most effective and most
recently developed is the Honolulu
technique.