MP1 New Approaches to Determining Soil and Sediment Exposures
256 Portland Ballroom
1:20 PM - 4:40 PM, Monday
() Biovailability of metals assessed MTL-2::GFP transgenic C. elegans.
Graves, A1, Williams, P1, Humphries, S2, Krizek, B2, Jagoe, C3, Stormberg, A4, Glenn, T3, 1 Dept Env Health Sciences, Univ of Georgia, Athens, GA, US2 Dept Biological Sci, Univ South Carolina, Columbia, SC, US3 Univ Georgia, Savannah River Ecology Lab, Aiken, SC, US4 INEEL, Idaho Falls, ID, US
ABSTRACT- We have developed transgenic lines of the nematode Caenorhabditis elegans incorporating a metal-specific promotor from metallothionein (mtl-2) that turns on a green fluorescent protein (GFP) reporter in the presence of bioavailable metals. This yields a MT based bioassay with a sort of "dimmer switch" where the amount of GFP produced is proportional to the level of bioavailable metal. The GFP reporter is a fluorescent product visible under blue light, avoiding the need for exogenous substrates and cofactors to detect MT induction. GFP is visible in live nematodes, permitting repeated measures over time, or measurement of MT before and after metal exposure in the same organisms. In initial experiments, Cd exposure induced Mt expression and increased GFP fluorescence. Our goal is to develop assays of metal bioavailability that would involve exposing worms to water or sediment in 96-well plates, then directly quantifying the response by measuring GFP fluorescence. This approach will greatly decrease the cost and effort required to assay metal bioavailability, while employing a relevant and realistic biological response in a well-characterized animal model.
Key words: transgenic, metallothionein, bioavailability, nematode