Agricultural Runoff in the Elkhorn River : Is Fate Bound to Vegetation?
Advisor Information
Alan Kolok
Location
Milo Bail Student Center Gallery Room
Presentation Type
Oral Presentation
Start Date
8-3-2013 10:00 AM
End Date
8-3-2013 10:15 AM
Abstract
Endocrine disrupting compounds (EDCs) contained in agricultural runoff saturate stream bank sediment where they remain bioavailable to fathead minnows (Pimephales promelas). The large surface area and lipophilic properties of plant cell walls suggest that common waterweed (Elodea canadensis) may compete with the fathead minnow as a ligand for the EDCs and as a result affect their bioavailability. To test this, female fathead minnows were exposed to tanks containing contaminated sediment collected from the Elkhorn River at West Point, NE, and varying plant concentrations of Elodea. Following exposure, analysis of hepatic estrogen receptor-α (ER-α) mRNA expression for each group both quantified defeminization and revealed a biphasic relationship between plant concentration and ER-α expression. As plant concentration increased from 0.4 g/L to 8.8 g/L ER-α expression increased. Interestingly, ER-α expression was markedly decreased at the highest plant concentration (24.7 g/L). These results suggest that at lower concentrations plants reduce the bioavailability of EDCs while at very high concentrations they exacerbate the anti-estrogenic effect.
Agricultural Runoff in the Elkhorn River : Is Fate Bound to Vegetation?
Milo Bail Student Center Gallery Room
Endocrine disrupting compounds (EDCs) contained in agricultural runoff saturate stream bank sediment where they remain bioavailable to fathead minnows (Pimephales promelas). The large surface area and lipophilic properties of plant cell walls suggest that common waterweed (Elodea canadensis) may compete with the fathead minnow as a ligand for the EDCs and as a result affect their bioavailability. To test this, female fathead minnows were exposed to tanks containing contaminated sediment collected from the Elkhorn River at West Point, NE, and varying plant concentrations of Elodea. Following exposure, analysis of hepatic estrogen receptor-α (ER-α) mRNA expression for each group both quantified defeminization and revealed a biphasic relationship between plant concentration and ER-α expression. As plant concentration increased from 0.4 g/L to 8.8 g/L ER-α expression increased. Interestingly, ER-α expression was markedly decreased at the highest plant concentration (24.7 g/L). These results suggest that at lower concentrations plants reduce the bioavailability of EDCs while at very high concentrations they exacerbate the anti-estrogenic effect.
Additional Information (Optional)
Winner of Meritorious Undergraduate Oral Presentation