Effect of copper on the development, protein and esterase isozymes of Drosophila melanogaster

Copper is an important ingredient in fungicides, which are used for many economic plants. However, there is concern about the side-effects of copper-based fungicides due to their potential to affect beneficial mites. The purpose of the present paper was to investigate the effects of copper on the development of the fruit fly, Drosophila melanogaster. It was found that higher doses of copper significantly prolonged the developmental time of the fruit flies, especially during the larval stages. When 320 mg L-1 copper-contaminated food was used, most of the larvae died when they were small and before the pupal stage. The protein contents and esterase isozymes extracted from the larvae changed according to the doses of copper. The small-molecular-weight protein bands gradually became weaker or were lost as the copper levels increased. However, low doses of copper stimulated a stronger expression of a few proteins. These results indicate that low doses of copper generally have no lethal effects on D. melanogaster because a specific group of genes, which encode specific proteins, are probably activated in order to withstand the onslaught of stressful conditions. At high doses of copper in food (e. g. 320 mg L-1), fly development and viability are significantly affected.