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Evaluation of Biological Activity of Vitellogenin Expression in Different Aquatic Mesocosm Tropic Levels
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| Abstract: | Aquatic mesocosms were dosed with an environmentally relevant concentration of 17-a-ethinyl estradiol (EE2) to study the significance of trophic status (N, P levels) on the attenuation and bioavailability of synthetic estrogens in aquatic ecosystems. Estrogenic activity was assessed by the measurement of vitellogenin gene (Vg) expression in the liver of caged adult male fathead minnows (Pimephales promelas) using synthetic oligonucleotide primers which detect Vg messenger RNA in a quantitative reverse transcription-polymerase chain reaction. Caged male adult fathead minnows (Pimephales promelas) were maintained in outdoor mesocosms at the University of Kansas' Nelson Field Station and exposed to 0 or 20 ng/L EE2 at oligotrophic (total N and P, 0.77 and 0.015 mg/L), mesotrohpic (total N and P, 1.09 and 0.022 mg/L), or eutrophic (total N and P, 1.99 and 0.032 mg/L) nutrient levels. Randomly selected individuals were sacrificed at timepoints of 0, hr, 8 hr, 24 hr, 4 days, 7 days and 14 days post exosure and the livers were harvested for total RNA preparation. Vg expression was observed as early as 8 hr post exposure in all three trophic levels. Trend differences were observed among the three levels at the various timepoints. These results indicate that trophic level is a critical factor for assessing bioavailability of synthetic estrogens to aquatic species as part of a complete ecological risk assessment. These results will also provide data for the systhesis of environmental compartmental models for the fate and transport of model EDCs in aquatic ecosystems. |
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| Citation: | Gordon, D. A., D. L. Lattier, J. M. Lazorchak, T. V. Reddy, L. W. Chang, G. P. Toth, D. W. Graham, F. J. Denoyelles, S. E. Campbell, D. E. Williams, and B. E. Wiechman. Evaluation of Biological Activity of Vitellogenin Expression in Different Aquatic Mesocosm Tropic Levels. 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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