Hi!
Here's a small piece I took from my website:
Clones have been produced from a 21-year old steer using quiescent cells
[Hill et al., 2000]; scientists then made a new clone taking cells from the
foetal clone and compared the percentage of successfully created clones: no
difference was found. Using diving cells scientists took cells from a
17-year old bull and allowed them to divide [Kubota et al., 2000]; they then
used cells at different senescing stages to create clones and amazingly it
appears that the older cells are more efficient. In another experiment,
cells aged in vitro were not less efficient for cloning than non-aged cells
[Lanza et al., 2000], as had been previously reported [Cibelli et al.,
1998].
For the bibliography see:
http://users.compaqnet.be/jpnitya/science/bible.htm
You wrote:
>Some fraction of the genomes harvested being "good enough" is sufficent
>explanation in my book.
That argument fails to explain the equal difficulties in making clones
taking cells from young donors. Perhaps the cell-types used are not the ones
in which aging originates (to my knowledge neurons have never been used to
make clones, perhaps aging originates in them); perhaps technical
difficulties hide differences between young and old cells (optimizing the
techniques might give ratios of success of, say, 50% for young cells and 30%
for old ones). Also remember that Lanza's and Cibelli's technique claims to
inject mtDNA; so you can't even say mtDNA mutations as the origin of aging
in these cases. Of course that the experiments I know are cross-sectional
studies but there is no reason to think longitudal studies on animal cloning
will yield different results.
>> I know there is at least one company that does what you propose (they
>> sent me some publicity a few months ago) but I really don't see the
>> point in it.
>
>The point would be as a backup strategy for individuals who are
>pessimistic about the harvesting of stem-cells that can be grown
>into organs as you grow older or who believe that whole genome
>syn-cells or nanobot genome replacements are a long way away.
>(Programmers try to look at all the possibilities.)
Murphy's law thinking!
Best wishes.
PS: Robert, are you going to St. Petersburg's Congress on aging?
---
Joao Pedro de Magalhaes
The University of Namur (FUNDP)
Unit of Cellular Biochemistry & Biology
Rue de Bruxelles, 61
B-5000 Namur BELGIUM
Fax: + 32 81 724135
Phone: + 32 81 724133
Reason's Triumph: http://users.compaqnet.be/jpnitya/
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