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From: diaz@aecom.YU.EDU (Dizzy Dan Diaz)
Newsgroups: sci.bio
Subject: Re: More on natural transformation
Message-ID: <1159@aecom.YU.EDU>
Date: Thu, 25-Jun-87 10:54:24 EDT
Article-I.D.: aecom.1159
Posted: Thu Jun 25 10:54:24 1987
Date-Received: Sat, 27-Jun-87 09:22:51 EDT
References: <401@uhnix2.UUCP>
Organization: Graduate School of Hard Knocks
Lines: 29
Keywords: CaCl2, philosophy
Summary: Nature and the Laboratory--Two Different Places

In article <401@uhnix2.UUCP>, bchso@uhnix2.UUCP (Dan Davison) writes:
> 
> Because the conditions under which mammalian cells uptake DNA, and
> under which E. coli do the same are not very likely to occur in nature.
> The Gram-positive style of transformation can occur in soil, whereas
> the calcium chloride bath that E. coli requires is less likely to be 
> be found in its natural environment.

What makes anyone think that E. coli has to be transformed in nature as
it is in the laboratory? We still don't understand what calcium does to
either of the bacterium's membranes or why heat shock, etc., are
necessary. I don't think it that difficult a problem, it's just that
molecular biologists have found other projects to waste their time on.

My point being that coli and similar bacteria may undergo transformation
quite frequently in nature by calcium-independent mechanisms. It would
be a mistake for me to measure Vmax or Km for some enzyme in the
laboratory and conclude that it or anything else I measure in the lab is
actually happening in the cell. I realize that this is heresy to those
who think everything we observe at 10 mM TRIS, pH 7.6 at 37 'C is real,
but unfortunately, it just ain't so. We just have to go on doing our
experiments, formulating theories and making models. Not that it really
matters whether what we observe is actually occuring, just as long as we
don't pretend too hard that it does.

-- 
   ....     dn/dx = Dan Diaz (philabs!aecom!diaz or diaz@aecom.yu.edu)
  ~..|.>    Department of Wasting Taxpayers' Money on Useless Research 
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