In a message dated 9/10/99 12:02:18 AM Pacific Daylight Time, bradbury@www.aeiveos.com writes:
> On Fri, 10 Sep 1999 CurtAdams@aol.com wrote:
>
> >
> > Well, yes, but developmental genes are off in adults. The developmental
> > tweaks we're getting good at are ineffective in adults and unsafe for
> > children.
>
> But are there any barriers to *enabling* them? I believe that there
> was a recent announcement that scientists had discovered a collection
> of 3-4 genes that in *adult* mice allowed wound healing to take on
> the characteristics of "normal development" rather than "scar tissue".
> If it doesn't involve dozens of genes, we already have the tools
> (though they are somewhat unrefined) to turn them on or off.
>
I believe that's just to make joe connective tissue. The genes involved
in making structures expect to be on in reasonable complex 3-D patterns.
There are hundreds of genes already known to be involved in development
and the number keeps going up.
All things considered, it might be easier to grow a human hand or kidney in a tissue-culture situation (actually, attached to some immunotolerant organism) than to regenerate it in the target.
>> For spare parts we need in vitro organs plus reactivation of neural
>> development.
>Would you perhaps qualify *what* organs need neural development and
>why? Heart, I might accept, liver or kidney I would be more skeptical
>about.
I agree with you on this; although virtually everything has and uses neural
connection it seems like a number of internal organs can get by without
it. I was thinking in terms of your example, hands. Livers, incidentally,
can
already regrow partially in vivo and I expect them to be the first
replaceable
organ.
>However,
Ahh, so grow the hand on (say) a pig, with its own nervous system, and then
put in an interface? Cute idea.
>the insertion of a neural-net mapping chip that is both "programmable"
>and has a much higher training rate than normal neurons seems a reasonable
>solution to this problem.