TRANSGENIC STRAINS OF THE NEMATODE C-ELEGANS IN BIOMONITORING AND TOXICOLOGY - EFFECTS OF CAPTAN AND RELATED-COMPOUNDS ON THE STRESS-RESPONSE

The fungicide, captan, induces a cellular stress response in the soil nematode Caenorhabditis elegans. Transgenic C. elegans, which produce beta-galactosidase as a surrogate stress protein, reveal that captan-i nduced stress is localized mainly to muscle cells of the pharynx. The stress response is elicited by captan concentrations above 5 ppm and o ccurs within five hours of the initial exposure to the fungicide. High er concentrations of captan, up to the solubility limit, increase the intensity of the response, Adult nematodes are significantly more sens itive to captan than are larvae, Captan also inhibits feeding in C. el egans, and nematodes exposed to captan rapidly cease muscular contract ions in the pharynx. Stress induction and feeding inhibition are also caused by the related fungicides, captafol and folpet, but not by the parent compounds, phthalimide and tetrahydrophthalimide. The inhibitio n of feeding caused by compounds which elicit the cellular stress resp onse may be an important survival mechanism for C. elegans.