RE: Radiation Evolutionary Effects

["Allen, Tim" <TAllen@jaguar.middlebury.edu>]

I read an article that you might be interested in called "Odd Microbe
Survives Vast Dose of Radiation" by Malcolm W. Browne, and refers to a paper
"published in the current issue of the journal science" by Dr. Kenneth W.
Minton and Dr. Michael J. Daly at Bethesda, MD.  I'm not sure when the
article was printed.  

Apparently the bacterium Deinococcus radiodurans was exposed to 15,000 Grays
of ionizing radiation, and survived!  It apparently contains several copies
of it's chromosomes, and uses the copies to form temporary bridges while
reassembling the chromosomes.

There's a similar article with further references online at
http://www.sciencenews.org/sn_arc98/12_12_98/Bob1.htm
and tons of site matches come up on a search for Deinococcus radiodurans on
Yahoo.


		Tim Allen
		Senior Laboratory Technician / Radiation Safety Technician
		601A Bicentennial Hall
		Middlebury College
		Middlebury, VT 05753
		Phone: (802)443-5729
            Fax: (802) 443-2072


> ----------
> From: 	Karam, Andrew
> Reply To: 	radsafe@romulus.ehs.uiuc.edu
> Sent: 	Thursday, August 10, 2000 2:20 PM
> To: 	Multiple recipients of list
> Subject: 	RE: Radiation Evolutionary Effects
> 
> Dear Kent (and others),
> 
	<snip>

> Finally, DNA damage repair is necessary for life as we know it because you
> have to be able to pass on genetic information in a reasonably consistent
> form from one generation to the next.  The damage repair must be accurate
> and it must work quickly enough to contend with background plus normal
> variations.  For life to exist at all, then, it almost certainly evolved
> damage repair early and has probably continued refining these mechanisms
> ever since.  A little bit of mutation is good - it's called evolution.  A
> lot of mutation is bad - in us it's called birth defects or cancer.  What
> would be interesting would be to see if there are any differences in the
> repair mechanisms between, say, a Galapagos tortoise (or any other very
> long-lived species) and those of insects, mice, or other short-lived
> species.
> 
> Andy
> 
> Andrew Karam, CHP              (716) 275-1473 (voice)
> Radiation Safety Officer          (716) 275-3781 (office)
> University of Rochester           (716) 256-0365 (fax)
> 601 Elmwood Ave. Box HPH   Rochester, NY  14642
> 
> Andrew_Karam@URMC.Rochester.edu
> http://Intranet.urmc.rochester.edu/RadiationSafety
> 
> The brain is a wonderful organ.  It starts working the moment you get up
> in the morning and does not stop until you get into the office.  
> Robert Frost
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