BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

DNA Repair More Efficient at Low versus High Doses of Ionizing Radiation
Published: December 19, 2011
Posted: January 12, 2012

The biological effects of ionizing radiation are determined, in part, by the efficiency with which radiation damage is repaired as a function of dose. The standard model of radiation-induced cancer risk applies a linear relationship to extrapolate from high to low doses of ionizing radiation. Scientists at DOE's Lawrence Berkeley National Laboratory, studying the formation of radiation-induced DNA repair-protein complexes, have shown that multiple DNA double-strand breaks produced 1 to 2 ┬Ám apart can rapidly cluster together to form damage repair centers. Surprisingly, they observed that the absolute number of repair centers is more than 4-fold smaller at high versus low doses of ionizing radiation. This new discovery supports the hypothesis that DNA damage repair is more efficient at low versus high doses of radiation and casts further doubt on current risk models, which assume that cancer risk from exposure to ionizing radiation is linearly proportional to dose in the low dose range.

Reference: Neumaier, T., J. Swenson, C. Pham, A. Polyzos, A. T. Lo, P. Yang, J. Dyball, A. Asaithamby, D. J. Chen, M. J. Bissell, S. Thalhammer, and S. V. Costes. 2012. "Evidence for Formation of DNA Repair Centers and Dose-Response Nonlinearity in Human Cells," Proceedings of the National Academy of Sciences (USA) 109(2), 443-48. DOI: 10.1073/pnas.1117849108. (Reference link)

Contact: Noelle Metting, SC-23.2, (301) 903-8309
Topic Areas:

  • Legacy: Low Dose Radiation, Radiobiology

Division: SC-33.2 Biological Systems Science Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)