Short-term exposures to chronically toxic copper concentrations induce HSP70 proteins in midge larvae (Chironomus tentans)

In the present study, we investigated the induction of HSP70 proteins in Chironomus tentans in response to copper exposure. Larvae were exposed for 24 h to 0, 0.25, 0.5, 1.0 and 2.0 mgl(-1) copper, concentrations that were previously shown to cause growth reduction or mortality in 10 d bioassays. The induction of HSP70 was evaluated by Western blotting, and we observed a significant increase in HSP70 proteins over controls at all tested concentrations. The results suggest that short-term laboratory exposures to chronically toxic but acutely sublethal copper concentrations induce HSP70 proteins in C. tentans larvae.