On Mon, 26 Nov 2001 firstname.lastname@example.org wrote:
> As I understand it, this was a cloning of an adult human being which
> was terminated at the embryo state. The idea was that the embryo
> could potentially be a source of stem cells for tissue engineering.
> However presumably the embryo could have been implanted and allowed to
> come to gestation as a cloned human being.
The capabilities have become extremely complicated at this point.
I am reasonably sure that it depends on precisely what paper by
specific groups one cites to determine what one is talking about.
- Cloning via nuclear transfer from adults seems feasible.
- Cloning via parthenogenesis in eggs (at least in primates) seems
feasible. (Note that you have no fertilization as well as the
potential for harmful gene penetrance here).
- Cloning via parthenogeneis after the transfer of the
nuclei (chromosomes?) into denucleated eggs from one or
two sperm may be possible.
- Cloning via transfer of nuclei into eggs of a different
species still seems open to question (???).
The reliability of these methods and the viability of offspring
still remain very open questions.
Bottom line is -- if you can produce something that produces
totipotent stem cells you have probably produced something that could
grow into an embryo/fetus (if implanted [with current technology]).
The nuclei of any cell (except red blood cells) in the human body
can produce another human being *if* you know what genes to turn
off/on to restart the cycle of development (and you can find an
environment that can support that development). We don't know
what those genes are yet *but* at some point we will.
This archive was generated by hypermail 2b30 : Sat May 11 2002 - 17:44:22 MDT