Posted 27 March 2004 - 02:10 AM
It seems that the cumulus cells from around a woman's egg have been the only cells used to date to clone a human embryo.
There was a study at Advanced Cell Technology which found younger cells were better for cloning than older ones. The downside of this, in cloning, is that fetal cells seem to work in nuclear transfer but divide a few times and then die. This was the reason for that "271-embryos-needed-to-produce-one-Dolly" story that so much attention.
In reality, only 29 embryos were produced from adult cells. These were implanted in eleven ewes and resulted in one live birth-Dolly. So, the actual success rate was close to the 3% success rate in the first IVF treatments.
Rudolf Jaenisch, the MIT researcher famous for declaring "there is no such thing as a normal cloned mammal" recently announced that he had produced "apparently healthy cloned mice" by using embryonic stem cells (mouse of course) for cloning. This might indicate that successful cloning in some mammals might require two rounds of SCNT.
I would suspect that germ cells in males, the cells that produce sperm, might be like cumulus cells surrounding eggs in women and would be good candidates for cloning.
Cloning from adult stem cells or the stem cells in umbilical cord blood would also seem to be excellent candidates. Should being cloned be one of your goals, full body cryonics should be considered. If germ cells were found to be needed, you would still possibly have some to retrieve.
In most cloning experiments, cells from the "growing" layer of skin cells have been considered good candidates. That may be because they have a long term ability to reproduce themselves.
