Toxicities of a trazine herbicide (atrazine) and an organophosphate insecticide (chlorpyrifos) were evaluated individually and in mixtures using the fourth instars of the aquatic midge, Chironomus tentans. Bioassay results indicated significant synergistic effects of atrazine on the toxicity of chlorpyrifos. To investigate molecular mechanisms of the synergistic effects of atrazine on chlorpyrifos toxicity, a new molecular technique known as restriction fragment differential display (RFDD) PCR was employed to compare the gene expression profiles of atrazine-treated and -untreated midges. Several over-expressed and under-expressed gene fragments were isolated and sequenced from the midges. Our preliminary studies suggest that RFDD-PCR is a robust technique that will allow us to not only compare the gene expression profiles in atrazine-treated and -untreated midges but also isolate specific genes that are affected by atrazine.
Species 1: Diptera Chironomidae Chironomus tentans (aquatic midge)
Keywords: Atrazine, Gene expression
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA