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USING THE DNA ALKALINE UNWINDING ASSAY TO DETECT DNA DAMAGE IN LABORATORY AND ENVIRONMENTALLY EXPOSED CELLS AND TISSUES
Citation:
Nacci, D. AND E. Jackim. USING THE DNA ALKALINE UNWINDING ASSAY TO DETECT DNA DAMAGE IN LABORATORY AND ENVIRONMENTALLY EXPOSED CELLS AND TISSUES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-89/419.
Description:
The DNA alkaline unwinding assay is being evaluated for use in the detection of DNA damage in marine animals exposed to environmental pollutants. n preliminary work, DNA unwinding methods were used with in vitro cell systems to demonstrate DNA strand breaks. ultured mammalian fibroblasts and sperm from marine fish and in vertebrates (Pseudopleuronectes, Arbacia, and Mytilus) showed concentration- dependent increases in DNA strand breaks after brief exposures to alkylating agents. NA unwinding methods were also used on DNA extracted from marine animals injected with genotoxicants and from animals exposed in situ at an estuarine site. ills from blue mussels caged at the New fjord Harbor Superfund Site (MA, USA) highly contaminated with many organic (e.g. PCBs) and inorganic contaminants, were also examined. ignificant increase in DNA strand breaks was seen in gill tissues of animals held in the contaminated site for as little as 3 days. lthough not as severe, an increase in strand breaks was also seen in animals held at the control site for 28 days. his apparent damage may have resulted from low-level contamination and/or from generally poor tissue condition. hese results suggest that DNA alkaline unwinding results from controlled experiment using cells briefly exposed to toxicants can be used to identify DNA strand breaking agents. hile whole-animal exposures to toxicants may affect DNA integrity, unwinding results may not specifically reflect genotoxicity.