From: Robert J. Bradbury (bradbury@ilr.genebee.msu.su)
Date: Fri Nov 19 1999 - 10:35:00 MST
> How hard is it to clone a human?
Which part? The cell culture & nuclear transfer technology could
probably be managed by many molecular biology graduate students.
What is hard (or expensive) is:
(a) harvesting the eggs
(b) implantation of multi-cellular embryo
(c) the failure rate (< 1 in 100 successes)
> I heard, from a biology major, that it's *relatively* easy, that she
> could do it herself with a few thousand dollars worth of equipment.
> Does anyone know if this is correct?
Probaly more like a few tens of thousands of dollars, but not way off.
> If so, I recommend to everyone reading this to learn as much about
> cloning methods as possible, if you are in a position to do so.
> Cloning for the purpose of procreation is pretty pointless, unless
> you have medical problems making you infertile.
Actually, cloning *does* make good sense for procreation purposes
if you want to copy people with specific traits. Yes, I know that
environment may be 50%+ of the picture, but genetics is still some
non-insigificant fraction.
> Its use in anti-aging technology is understated though.
No, I've discussed in various posts. I think cloning is *overrated*
as an anti-aging technology. Cloning allows you to make a new body
and brain, and unless you have the technology to create the body
without the brain, you are in highly unethical areas.
> Stem cells which new, young organs could be grown from would be
> rejection-proof if cloned from the individual they are to be placed into.
Huh??? How did we cross from cloning to stem cells. These are two
different but related things. Current thinking is that adults still
posesses many stem cells with greater or lesser degrees of "totipotency"
(capability of forming many organs). I'd give better than even odds
that within the decade, we find a way to make differentiation run
backwards so you can turn a normal cell back into a stem cell
(though it may have more accumulated mutations than a typical stem cell).
Stem cells of various types should give you the ability to grow organs
of various types in the lab (without the requirement for a body).
The only thing that "cloning" provides is the ability to grow the
organs "naturally". Given the slow growth rate of the organs and
the costs of maintaining a body for many years (until the organs
become large enough) in my mind makes "cloning" for "organ replacement"
a very dismal prospect.
Also worth noting -- the problem currently isn't really "rejection"
(this is fairly well understood and can be controlled "most" of the
time). The problem really is the overall organ supply relative
to the demand.
The logical steps will be:
(a) Engineering pigs so they can provide less rejectable organs.
[Cross-species rejection has not been solved yet, though the
causes are understood and these are being addressed.]
(b) Growing orgrans on disolvable plastic frames from stem cells.
Requires a bit more work on getting growth factors correct
and being able to harvest appropriate stem cells from the
transplant recipient or other compatible donors. [But the
donor supply goes up signifcantly when you only a few stem
cells are needed and you don't have to be dead to give them.]
(c) Re-engineer tissue specific "artificial" stem cells to serve
as organ substrates. These will be "enhanced" over the natural
versions (faster division & growth, better DNA repair, etc.).
(a) and (b) are the current-to-~2010 time frame. (c) is the ~2005
to ~2015 time frame. I can't see any progress being made on "natural"
clones for transplants due to the furor it will produce in the same
time frame. Once people get it straight that the wetware we run
on are nothing more than machines, then people may choose to work
on this but there will not be much point by then.
Cloning *will* get worked on for its importance for people who want or
need to copy their favorite pet or prize bull or horse (in agribusiness).
Here the ethical issues are pretty moot (which may make an for an
*interesting* comment on how messed up "ethics" is).
> It's also possible that neural stem cells could hold as much promise
> in combating general aging-related dementia as they do for specific
> diseases like alzheimer's and parkinson's, or maybe even enhance memory
> and cognitive function in normal individuals.
True. But these simply require indefinately propagating neuronal stem
cell lines. These are being worked on.
> Given the hysteria over cloning, and its imminent banning
> (I'm 99% confident it will be banned for several decades at least),
Well its banned in parts of Europe and the article mentioned was for
Japan, but the U.S. seems to be running a middle path of saying
we do not want to ban these things outright until we clearly see
harm over benefits (few would argue benefits of "cloning" per se,
but many would argue the benefits of stem cell research and related
technologies, so we are being careful not to throw out the baby with
the bathwater). The Japanese article also made it clear that the issue
should be reexamined in 5 years.
> it's important to set up an infastructure of some sort in which
> research and medical usage of cloning can be done illegally.
Its important to push on the understanding stem cell isolation
and the control of differentiation (development & regression).
A reasonable prioritization based on the relative impacts of
the solutions would be:
a) solve the organ supply problem
b) reduce the "cost" of the organs (grow them faster/cheaper)
c) minimize the rejection problems (make them look like the recipient)
I'm not convinced that "cloning" technologies make any significant
contribution in these areas.
Robert
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