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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 7033

L.K. Cioci, Ling Qiu, and Jonathan H. Freedman; Transgenic Strains of the Nematode Caenorhabditis elegans as Biomonitors of Metal Contamination. Environmental Toxicology & Chemistry 19(8):2122-2129, 2000

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Transition metal contamination poses a serious environmental and human threat. The bioavailability of transition metals in environmental samples can best be assessed with living organisms. A transgenic strain of the free-living soil nematode Caenorhabditis elegans has been engineered for monitoring the bioavailability of metals. A reporter transgene consisting of a fragment of the promoter from the C. elegans metallothionein-2 gene (mtl-2) that controls the transcription of a beta-galactosidase reporter (lacZ) has been integrated into the genome of this organism. By using these transgenic C. elegans, the toxicological response to metals in samples can be quickly measured with a simple histochemical staining assay. The C. elegans that contain the mtl-2:lacZ transgene provide a more sensitive assay of exposure to cadmium, mercury, zinc, and nickel than 24-hr LC50 assays or those using nematodes with heat-shock protein-based reporter transgenes. This study demonstrates that C. elegans that contain mtl-2:lacZ transgenes can function as sensitive toxicological indicators of metals.