This U.S.-U.K. cooperative research project between Deborah Neher of the University of Toledo and Stephen Sturzenbaum of Cardiff University in the United Kingdom involves investigations of soil nematodes (roundworms) as bioindicators of soil health and environmental contamination. Neher and her colleagues have conducted fundamental experiments to test the reliability, cost-effectiveness, utility and quality assurance of nematode community indices for environmental monitoring. They plan to use changes in nematode DNA as biomarker for rapid detection of sensitive genotypes to broad classes of chemical compounds or specific xenobiotics. The will demonstrate that (1) DNA adducts can be identified and quantified reliably using XL-PCR in a model nematode, Caenorhabditis elegans with validation on field-relevant species, and then (2) quantify concentration-response relationships between contaminant concentration and DNA adduct formation.
Intellectual Merit: The project applies PAHs (organic chemicals) as xenobiotics on soil microfauna and an existing biomarker, DNA adducts, to ecological analysis. This technology can serve as a relatively quick and definitive measure of relative sensitivity of soil nematode genotypes to chronic exposure to environmental stressors and contaminants. The objectives are to establish an independent empirical evaluation of assignments for community indices and sensitive genotypes (sequences) that could be targeted by molecular probes.
Broader Aspects: Many soils are contaminated with heavy metals worldwide. In contrast, contaminated sites abandoned by industry are laden with organic chemicals such as PAHs or a mixture of metals and organics. Currently, nematode communities are proposed as a national bioindicator of soil health in the State of the Nation's Ecosystems Report in the U.S. The proposed study will develop environmental tools that can be used both to monitor soil quality; and quantify progress of remediation of waste sites and contaminated sediments. The non-specialist may find this a useful and cost effective tool for implementing nematode bioindicators within large-scale environmental monitoring programs of aquatic and terrestrial ecosystems. Furthermore, the approach may be appropriate for studying population genetics and evolutionary change in soil communities.
The project takes advantage of Dr. Stephen Sturzenbaum's expertise in quantitative PCR and handling extra-long fragments of DNA, two skills essential to the proposed project. The U.S. PI will master this approach and then U.S. train graduate students in these tools for evaluating soil ecology.
