Re: Soft tissue: what can we expect to learn?

[Daniel Arndt <danielarndt@hotmail.com>]

What about mitochondria, along with mitochondrial DNA?

Given that I'm not a microbiologist, and don't know too much about it, what
are the chances that mitochondria may be present in any of the intact cells,
and then what are the chances that those mitochondria have at least a
portion of their mDNA intact?

The implications of the mDNA testing that could be done could give us a very
clear picture of the phylogenetic relationships of Tyrannosaurs to birds
(and give us a fairly accurate picture of where their closest common
ancestor is...)

- Dan

----- Original Message -----
From: "frank bliss" <frank@blissnet.com>
To: <pristichampsus@yahoo.com>
Cc: <dinosaur@usc.edu>
Sent: Saturday, March 26, 2005 5:39 PM
Subject: Re: Soft tissue: what can we expect to learn?


> Fragments of DNA are not out of the question BTW.  DNA directs protein
> synthesis so at a minimum, some DNA structure may be inferred.  Any
> cellular structures preserved would be a bonus in the study.  Since
> none of us has seen the material, it would be impossible to speculate
> on what can be learned.  Many secondary cellular mechanisms of the
> creature such as what amino acids (in affiliation with those proteins)
> are present from the breakdown of those proteins. That being said.
>
> There are common proteins produced by many mechanisms and there are
> those more rarely expressed by unique metabolic processes.  Based on
> antibody reaction to protein presence, one can infer (based on what
> occurs of course) what processes were involved in the production of the
> particular protein.  Metabolic pathways often produce specific
> proteins.  (I suspect that even most of these proteins will be
> fragmentary as well.) Presence or absence of a particular molecule may
> denote these processes and thusly an analogue can be made to modern
> equivalent metabolic activity.  Perhaps even rare exotic protein
> occurrences may show even phylogenetic affinities and relationships.
> Anything might come out of the study.
>
> Regarding thermophysiological affinities, certainly  a basis for such
> conclusions could be reached if the proteins identified have modern
> relationships to temperature regulatory mechanisms.  Most reporters I
> have met would have to ask how to spell thermophysiological let alone
> make conjecture about it.  Things we may not expect like thermally
> regulatory related thyroid hormones such as thyroxine et al may be
> present or even catacholamines which may shed light on thermo balance.
> Sugars may be found as well which may shed light on many cellular
> processes.  How about some complete mitochondria just for good measure.
>   Heck, someone might be able to figure out the entire cellular
> metabolism with the right preservation. I don't think anyone can
> accurately speculate what WILL be found until the proteins (and other
> metabolites) are identified specifically if at all.  Remember your
> biochemistry, it is not just proteins, there are lipids, esters,
> anhydrides, sugars, enzymes and a host of others that could pop out of
> the soup.  A little molecular biology will go a long way here.  Even
> some old viruses, bacteria and fungi might reanimate.
>
> A good cell biology team needs to be assembled to work the specimen and
> perhaps more of the same creature should be sacrificed to acquire more
> material.  Most of the bones that I have collected from Hell Creek have
> been penetrated by modern groundwater/roots/bacteria etc.  It is sure a
> cool find.
>
> Frank Bliss
> MS Biostratigraphy
> Weston, Wyoming
>
>
> On Mar 26, 2005, at 12:52 PM, Jura wrote:
>
> > Okay, so we know that DNA is out of the question, and
> > that protein, or protein fragments are our best bet.
> > With that in mind, what can we expect to learn from
> > this find?
> >
> > I didn't hear the Don Lessem interview, so I don't
> > know what he mentioned, but I do see a lot of the news
> > reports saying that this could help identify the
> > thermophysiological affinities of _T.rex_. Is that
> > just typical, journalistic conjecture, or is there any
> > truth to this?
> >
> > Offhand, I can't think of anything in a basic protein,
> > that would indicate one metabolic preference over the
> > other. The only thing that comes to mind, is finding a
> > protein with an analogue/homologue which has a very
> > narrow temperature tolerance. But given the efficiency
> > of active thermoregulation, combined with thermal
> > inertia, and the generally warm Mesozoic environment,
> > I can see, even that, going both ways.
> >
> > Perhaps these proteins could hint at immunological
> > capacity, or digestive efficiency (though, given that
> > they came from a femur, I'm doubtful of the latter).
> >
> > Anyway, I'm curious to see what other listmembers
> > think these proteins could shed light on. You know,
> > other than the fact that _T.rex_ had proteins. :)
> >
> > Jason
> >
> > "I am impressed by the fact that we know less about many modern
> > [reptile] types than we do of many fossil groups." - Alfred S. Romer
> >
> >
> >
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