Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!sunybcs!ubvms.cc.buffalo.edu!v151luy2
From: v151luy2@ubvmsa.cc.buffalo.edu (Scott D McGinnis)
Newsgroups: sci.bio
Subject: Re: Reviving extinct species
Message-ID: <29670@eerie.acsu.Buffalo.EDU>
Date: 29 Jun 90 22:09:14 GMT
Sender: news@acsu.Buffalo.EDU
Reply-To: v151luy2@ubvmsa.cc.buffalo.edu
Organization: University at Buffalo
Lines: 48

>There are numerous examples of organic material surviving from
>extinct species. For example, frozen woolly mammoths have been found
>in the Soviet Union. Hides believed to be from giant sloths have
>turned up in South America (it's believed th giant sloths might have
>only become extinct a few hundred years ago in South America).
>And stuffed Do-Do's and other extinct birds are in many museums.
> 
>My question is, is there enough intact genetic molecules in these
>organic samples with which to perform cloning? For example, using 
>current cloning technology, is it feasible to remove genetic material 
>from the organic matter of extinct species, and implant it into 
>existing ones? For example, could one cross fertilize an elephant 
>with the genetic material from the frozen baby mammoth found in the 
>Soviet Union earlier this century? How long do complex genetic molecules 
>survive, in the best of conditions? In the field of paleobiology, how 
>large of genetic remnants survive from pre-mammalian history, say, from 
>the dinosaur eras and before? 
> 
	Well this is certainly an interesting topic, the most in the 
recent history of this newsgroup I dare say. The fact is that the
very experiment you have proposed has occured. Just recently a 
group of researchers headed by S. Paabo cloned bits of the genome
of an extinct species: The Marsupial Wolf of Australia, from a 
stuffed museum specimin (Nature. 340 (6233): 465-7.)
	Their research was to compare a 219 bp stretch of mitochon-
drial DNA to that from living marsupials in South America. The re-
sults suggest that the most direct ancestor to the marsupial wolf
in Australia evolved on that continent and not S. America.
	But this is not important to answering your question. In fact
I am aware of several other examples of cloning "ancient" genes
in the new field of molecular archaeology. The revolution occured
w/ the invention of the polymerase chain recation technique or
PCR. 
	Briefly this is a sensitive method of replicating very tiny
amounts of DNA. Originally used in biochemistry to amplify small
amounts of DNA extracted from living cells, it can be used to 
"copy" small amounts of DNA which has been desicated. DNA is 
extremely stable over long periods of time. Small plasmids are
kept at 4 degrees C in solution almost indefinately, but large
pieces of chromosomal DNA can be stored desicated on the shelf.
In fact I have a small jar of total DNA extracted from salmon
sperm on my desk for about two years.c Its still good once in 
soltion.
	For a review on both PCR and molecular archaeology try
J. Biol. Chem. 264 (17): 9709-12 S. Paabo et. al.
	As for the cloning of whole animals, well I think that for 
now must remain in the rhelm of sci. fi.
						S. D. McG.