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Biological responses to the simulated Martian UV radiation of bacteriophages and isolated DNA

Paper ID Volume ID Publish Year Pages File Format Full-Text
30559 44486 2008 7 PDF Available
Title
Biological responses to the simulated Martian UV radiation of bacteriophages and isolated DNA
Abstract

Mars is considered as a main target for astrobiologically relevant exploration programmes. In this work the effect of simulated Martian solar UV radiation was examined on bacteriophage T7 and on isolated T7 DNA. A decrease of the biological activity of phages, characteristic changes in the absorption spectrum and in the electrophoretic pattern of isolated DNA/phage and the decrease of the amount of PCR products were detected indicating damage of isolated and intraphage T7 DNA by UV radiation. Further mechanistic insights into the UV-induced formation of intraphage/isolated T7 DNA photoproducts were gained from the application of appropriate enzymatic digestion and neutral/alkaline agarose gel electrophoresis. Our results showed that intraphage DNA was about ten times more sensitive to simulated Martian UV radiation than isolated T7 DNA indicating the role of phage proteins in the DNA damage. Compared to solar UV radiation the total amount of DNA damage determined by QPCR was about ten times larger in isolated DNA and phage T7 as well, and the types of the DNA photoproducts were different, besides cyclobutane pyrimidine dimers (CPD), double-strand breaks (dsb), and single-strand breaks (ssb), DNA-protein cross-links were produced as well. Surprisingly, energy deposition as low as 4–6 eV corresponding to 200–400 nm range could induce significant amount of ssb and dsb in phage/isolated DNA (in phage the ratio of ssb/dsb was ≈23%/12% and ≈32%/19% in isolated DNA). 5–8% of the CPD, 3–5% of the AP (apurinic/apyrimidinic) sites were located in clusters in DNA/phage, suggesting that clustering of damage occur in the form of multiple damaged sites and these can have a high probability to produce strand breaks. The amount of total DNA damage in samples which were irradiated in Tris buffer was reduced by a factor ∼2, compared to samples in phosphate buffer, suggesting that some of the photoproducts were produced via radicals.

Keywords
Simulated Martian UV radiation; DNA; Bacteriophage; UV damage; QPCR; UV photoproducts in bacteriophage/isolated DNA
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Biological responses to the simulated Martian UV radiation of bacteriophages and isolated DNA
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 92, Issue 2, 21 August 2008, Pages 110–116
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us