Exploring the use of transgenic Caenorhabditis elegans as a measure of soil toxicity

Transgenic strains of the nematode Caenorhabditis elegans carrying a green fluorescent protein (GFP) reporter gene show great potential for furthering the acceptability of using nematodes in soil toxicity tests. In C. elegans GFP is well expressed, easily observed, and can be quantified in living worms. Strains exhibiting intense localized fluorescence are easier to recover both from artificial soils and from field collected soils that contain indigenous nematode populations. A transgenic strain of C. elegans may also be useful for monitoring the bioavailability of metals. A reporter transgene consisting of a promoter from the C. elegans metallothionein-2 gene (mtl-2) that controls the transcription of a GFP reporter was integrated into the genome of this strain. By using a fluorescent microplate reader, the toxicological response to metals can be quickly measured in these organisms.