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Vitellogenin Gene Expression in Fathead Minnows Exposed to Ee2 in a Whole Lake Dosing Experiment
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| Abstract: | A whole-lake endocrine disruption experiment was conducted by Fisheries and Oceans Canada at the Experimental Lakes Area (ELA), northwestern Ontario in 2001 and 2002. This experiment examined population, organism, biochemical and cellular-level effects in lake trout, white sucker, fathead minnow, and pearl dace exposed to environmentally-relevant (4-6 ng/L) concentrations of the synthetic estrogen, 17a ethynylestradiol. The USEPA collaborated in this study by evaluating vitellogenin gene expression (Vtg) in male fathead minnow livers: 1) from indigenous fish collected from the dosed and control lakes four times, once before dosing and up to three times after dosing; 2) in 2001 from indigenous minnows collected from the control lake and deployed for 1, 3, 7 and 13 days in the dosed and control lakes; and 3) in 2001 and 2002 from Cincinnati cultured minnows exposed to water collected from both ELA lakes and shipped to Cincinnati. RT-PCR methods were used for measuring Vtg expression. In addition to water exposures, embryo-larval fish were exposed to control and dosed lake sediment elutriates for 5 days. Gene expression in indigenous male fatheads collected at all time intervals from the dosed lake showed a constant level of elevation. Gene expression in the 2001 deployment study was detected within 24 hours after deployment of control fish into the treated lake and stayed elevated for the entire 13-day study. Highly variable gene expression was found in fry exposed to dosed lake sediments but no significant gene expression was found in fry exposed to control lake sediments. Results indicate that RT-PCR analyses of total RNA can be used to provide a rapid and timely estimate of exposure to estrogenic substances. |
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| Citation: | Lazorchak, J. M., R. Flick, D. L. Lattier, K. Kidd, V. Palace, M. E. Smith, B. E. Wiechman, T. Hodge, and G. P. Toth. Vitellogenin Gene Expression in Fathead Minnows Exposed to Ee2 in a Whole Lake Dosing Experiment. Presented at Society of Environmental Toxicology and Chemistry, Austin, TX, November 8-13, 2003. |
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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: |
11/08/2003 |
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