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From: szabo@crg5.UUCP (Nick Szabo)
Newsgroups: sci.bio
Subject: Re: Reconstructing cells from DNA
Message-ID: <21567@crg5.UUCP>
Date: 17 Apr 91 21:12:06 GMT
References: <1991Apr16.235422.20331@cunixf.cc.columbia.edu> <1991Apr17.013059.7708@alchemy.chem.utoronto.ca>
Reply-To: szabo@crg5.UUCP (Nick Szabo)
Organization: Sequent Computer Systems, Inc
Lines: 31

In article <1991Apr17.013059.7708@alchemy.chem.utoronto.ca> mroussel@alchemy.chem.utoronto.ca (Marc Roussel) writes:
>...if a dinosaur could be produced from fossilized DNA....
>If DNA were the blueprint which many claim it to be, then certainly we
>could reproduce an entire organism from its DNA.  However it is my
>contention that unless we know something about the environment in which
>development of the original owner of the DNA occured, we would have no
>hope of reproducing the organism from its genetic material alone.  Thus
>we might be able to get a dinosaur by guessing that a modern reptile
>would provide an appropriate environment for dinosaur genetic material,
>but we would have no hope of getting a functioning organism from an
>unidentified piece of DNA.

The question is, what conditions in the surrounding zygote must be
present in order for the DNA to run its embryological course and
produce fertile offspring?  Tbe answer is, a whole bunch of stuff -- 
from the immediate transcription RNA to the whole "digestive system"
of the zygote.  Much of this is based on that or similar DNA from the 
_previous_ generation.  Thus, it is somewhat of a recursive problem.  Dare 
I say "chicken and egg" problem?  :-)

BTW, what is the current status of research on using host mothers of common
species for endangered species?  I seem to remember some zoo had a common 
tiger female giving birth to an endangered tiger a few years back, but
I don't remember any of the details...


-- 
Nick Szabo			szabo@sequent.com
"The biscuits and the syrup never come out even" -- Robert A. Heinlein
The above opinions are my own and not related to those of any
organization I may be affiliated with.