| Nuclear
Transfer (a general
overview) |
|
|
First
explored by Hans
Spemann
in the 1920's to conduct genetics research, nuclear
transfer is the technique currently used in the cloning of adult animals. A technique
known as twinning exists, but can only be used before an
organisms cells differentiate. All cloning experiments of
adult mammals have used a variation of nuclear transfer. 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 cells 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. [ Home ] [ The Details ] [ Reactions ] [ Interactions ] [ About Site ] [ Bibliography ] |