Seminar Details
Helen Poynton, UC Berkeley
The eve of ecotoxicogenomics: gene expression profiling in Daphnia magna
November 14, 2004 to
November 18, 2004
Portland, Oregon, USA
Abstract:
Fourth SETAC World Congress & 25th Annual Meeting in North America
Poynton, H, Komachi, K, Chang, B, Loguinov, A, Holman, P, Hughes, O, Vulpe, C, Department of Nutritional Sciences and Toxicology, UC Berkeley, Berkeley, CA, USA & Eon Corporation, Davis, CA, USA
Despite the threat that pollution poses to aquatic ecosystems, the present methods for identifying the chemicals responsible for toxicity in the environment are not specific or simplistic enough for routine monitoring. The emerging field of ecotoxicogenomics involves using gene expression profiling to both sensitively indicate stress to an ecosystem and identify the casual agents. Ecotoxicogenomics has the potential to change the way that water quality is assessed by providing enhanced sensitivity and new insight into the chemicals responsible for causing toxicity. Our research is attempting to assess the potential of this emerging field. We are developing a cDNA microarray based method for evaluating the effects of contamination on aquatic environments using the indicator species Daphnia magna. Changes in gene expression in D. magna will be correlated with specific chemical contamination in the environment. To determine the feasibility of using gene expression as an indicator of chemical contamination, we have constructed cDNA microarrays containing D. magna genes related to toxicant stress. We will be presenting the results of our microarray hybridizations including gene expression profiles for copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb) exposure. In addition, we intend to reveal the genes, which are uniquely regulated by exposure to each of these metals and constitute potential biomarkers of exposure. Our future research aims include: (1) determining the sensitivity of gene expression profiling, (2) challenging the cDNA microarray to identify metal toxicants when they are present in mixtures, and (3) validating the use of gene expression by testing field samples. This research will illustrate the utility of cDNA microarrays in ecotoxicology and will reveal the potential of ecotoxicogenomics for water quality assessment.
