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Ecotoxicogenomics: Exposure Indicators Using Ests and Subtractive Libraries for Multi-Life Stages of Pimephales
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| Abstract: | Ecotoxicogenomics is research that identifies patterns of gene expression in wildlife and predicts effects of environmental stressors. We are developing a multiple stressor, multiple life stage exposure model using the fathead minnow (Pimephales promelas), initially studying four chemicals across three early life stages. We report studies of fathead minnows exposed to 17-a-ethinyl estradiol (0, 2, 5, 10 and 20 ng/L) for 24 h at the following life stages: 7 days old, 14 days and 60 days. These stages correspond to distinct developmental windows prior to notable reproductive organogenesis. Early development was targeted because of the genomic plasticity and the legions of transcriptional programs occurring during ontogeny. Following exposure, total RNA was isolated from organisms pooled by age and across doses. This RNA was used to construct forward and reverse cDNA subtraction libraries for each life stage, or to identify expressed sequence tags (ESTs) using differential display. Several differentially expressed products show identity with structurally characterized teleost sequences in GenBank. Subtractive cDNA clones will be used to construct an exposure-specific Pimephales microarray. The identical approach will be applied with a pesticide, common environmental metal, and a potent inducer of the P4501A1 gene. Following generation of these libraries, a multi-exposure microarray will be assembled. This will yield the foundation of expressed gene patterns that correlate with single or complex toxicant exposures, and the relative bioavailable concentrations of environmental stressors. This approach will also identify genes critical in early development, the disruption of which could influence reproductive outcomes, and detect differential expression patterns influenced by chronic chemical exposure, in comparison to acute onset of exposure. |
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| Citation: | Lattier, D. L., R. Flick, J. M. Lazorchak, G. P. Toth, M. E. Smith, D. E. Williams, and B. E. Wiechman. Ecotoxicogenomics: Exposure Indicators Using Ests and Subtractive Libraries for Multi-Life Stages of Pimephales. Presented at Society of Environmental Toxicology and Chemistry, Baltimore, MD, November 11-15, 2001. |
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| Contact: |
Linda Ransick - (513) 569-7395 or ransick.linda@epa.gov
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| Division: |
Ecological Exposure Research Division |
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| Branch: |
Molecular Ecology Research Branch |
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| Product Type: |
Abstrct/Oral |
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| Presented: |
11/11/2001 |
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