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    A New Alphabet: Carbon-14 Natural Radioactivity May Mutate DNA Outside The Four Letters
    By News Staff | December 17th 2013 09:40 AM | Print | E-mail | Track Comments

    Recently, scientists have begun to make precise genetic modifications to genes in order to move a beneficial effect of one plant to another. This is not without controversy but far superior to prior methods of optimizing plant biology.

    The most random thing that can happen is letting natural radioactivity within DNA alter chemical compounds, providing a new pathway for genetic mutation.

    Radioactivity occurs naturally in our bodies as well as in every living organism across the planet and  a new paper looked at natural radioactivity within human DNA on the atomic-scale. It was not known to affect our DNA in such a direct way but in a new paper the team was able to show radioactivity could alter molecular structures which encode genetic information, creating new molecules that do not belong to the four-letter alphabet of DNA.

    Professor Nigel Marks of 
    Curtin University
    said the new molecules may well generate mutations by confusing the replication mechanisms in DNA. "This work takes an entirely new direction on research into natural radioactivity in biology and raises important questions about genetic mutation. We have discovered a subtle process that could easily be overlooked by the standard cell repair mechanisms in the body, potentially creating a new pathway for mutations to occur." 

    Marks said the work was both exciting and unexpected, emerging as a spin-off from an Australian Research Council funded project on nuclear waste. 
    The natural radioactivity in focus involved the decay of carbon atoms, Carbon-14, turning into nitrogen atoms, Nitrogen-14.

    "As part of the project between Curtin and Los Alamos we developed a suite of computational tools to examine deliberate radioactivity in crystalline solids, only to later realise that the same methods could be applied to natural radioactivity in molecules. This direction was an unplanned outcome of our research program – just the way blue skies research should be."

    Carbon-14 is one of the most abundant forms of radioactive decay occurring in biological systems. Over a human lifetime, around 50 billion Carbon-14 decays occur within our DNA.

    "While it is still not obvious how DNA replication is affected by the presence of chemical compounds that are different to the four-letter alphabet of DNA, it is quite remarkable to consider that Carbon-14 could be a source of genetic mutation that would be impossible to avoid due to the universal presence of radiocarbon in the environment," Professor Marks said.



    Published in
    published in Biochimica et Biophysica Acta-General Subjects. Source: Curtin University