Development and Validation of the Daphnia cDNA Microarray as a Method for Predicting Metal Contamination in Aquatic EnvironmentsEPA Grant Number: FP916442
Title: Development and Validation of the Daphnia cDNA Microarray as a Method for Predicting Metal Contamination in Aquatic Environments
Investigators: Poynton, Helen C.
Institution: University of California - Berkeley
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $96,994
RFA: STAR Graduate Fellowships (2004) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Biology/Life Sciences , Fellowship - Biochemistry, Molecular Biology, Cell Biology, Development Biology, and Genetics
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. When an organism is exposed to toxic substances, it responds and adapts to the stress by altering the regulation of genes and proteins. The emerging field of ecotoxicogenomics attempts to exploit this process by measuring the changes in gene expression to both indicate stress to an organism and identify the casual agents. Ecotoxicogenomics has the potential to change the way that water quality is assessed in the United States by providing enhanced sensitivity and new insight into the chemicals responsible for causing toxicity. The objective of my proposed research is to determine the potential of this emerging field.
This research involves development of 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, cDNA microarrays containing D. magna genes related to toxicant stress have been constructed. The current object of this research is to show that the metals copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb) induce specific gene expression profiles in D. magna. In addition, I am attempting to identify genes that are uniquely regulated by exposure to each of these metals and constitute potential biomarkers of exposure. My 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.