Massachusetts General Hospital Results of a recent study titled "Deinococcus
geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks,"
will be
published in the Sept. 26 edition of PLoS ONE. The study headed by Michael
J. Daly, Ph.D., associate professor at the Uniformed Services University
of
the Health Sciences' (USU), Department of Pathology, reports the
whole-genome sequence of Deinococcus geothermalis, which is only the
second for an
extremely radiation- and desiccation-resistant bacterium. The first was
for the Guinness World Records-holder Deinococcus radiodurans, which for
50
years has been the subject of extensive investigations aimed at solving
the mystery of how this microbe and its close relatives survive immense
doses
of x-rays and gamma-rays.
Most surprisingly, many of the unique D. radiodurans genes that were
strongly implicated in resistance over the last decade have turned out to
be
unrelated to its survival, and are not present in D. geothermalis. Using
computer-based systems to compare the D. geothermalis genome sequence with
the sequence of D. radiodurans, a minimal set of genes which encode
extreme resistance was defined. Far fewer genes than initially believed
appear to
be responsible for the extreme resistance trait, which bodes well for the
long-term prospects of conferring radiation resistance to other organisms.
The phenomenal resistance of Deinococcus bacteria has given rise to
numerous descriptions of their origin, including that they evolved on Mars
under
harsh cosmic radiation. The present analysis firmly places the origin of
Deinococcus bacteria on Earth, where the evolutionary steps that led to
their
survival mechanisms clearly occurred in their terrestrial ancestors - most
likely in a desert near you.
The complete manuscript can be read in PLoS ONE at:
plosone. PLoS ONE is an open-access, peer-reviewed journal
which reports primary
research from all disciplines within science and medicine. By not
excluding papers on the basis of subject area, PLoS ONE facilitates the
discovery of
the connections between papers whether within or between disciplines.
Deinococcus geothermalis was chosen for whole-genome sequencing by the U.
S. Department of Energy (DOE), Office of Science, Office of Biological and
Environmental Research with Dr. Daly as the Principal Investigator. The
genome sequence was acquired at the DOE-Joint Genome Institute (JGI),
Walnut
Creek, CA, and subjected to comparative analysis at the National Center
for Biotechnology Information, National Library of Medicine, National
Institutes of Health (NIH), Bethesda, Md. D. geothermalis was previously
engineered by Daly's group for cleanup of radioactive waste sites. The
three-year project was a collaboration between USU, DOE-JGI, NIH, DOE's
Advanced Photon Source and Pacific Northwest National Laboratory, and the
Russian Academy of Sciences.
USU is located on the grounds of the National Naval Medical Center in
Bethesda, Md. The university provides military and public health-relevant
education, research, service and consultation to the nation and the world,
pursuing excellence and innovation during times of peace and war.
Citation: Makarova KS, Omelchenko MV, Gaidamakova EK, Matrosova VY,
Vasilenko A, et al (2007) Deinococcus geothermalis: The Pool of Extreme
Radiation
Resistance Genes Shrinks. PLoS ONE 2(9): e955.
doi:10.1371/journal.pone.0000955
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