Biochemical CuSO Toxicity in Drosophila melanogaster Depends on Sex and Developmental Stage of Exposure.

Copper is a transition metal that exists in different chemical forms (e.g., Cu,Cu, and Cu) and at high concentrations it is toxic. Here, we investigated the Cu-induced toxicity in Drosophila melanogaster, evaluating the survival, locomotion, and the activity of acetylcholinesterase (AChE) and glutathione S-transferase (GST) enzymes. Flies were exposed to Cu(0.1-1 mmol CuSO/kg of diet or approximately 0.1-1 mM Cu) and allowed to mate during 24 h. GST and AChE enzymes were evaluated in the larvae and in the head and the body (thorax + abdomen) of the adult male and females flies. The total number of adult females (0.4-1 mM) and males (0.75 and 1 mM) was decreased by CuSO. The climbing ability was hampered in flies exposed to 1 mM Cu. In larvae, Cu(0.4-1 mM) increased AChE activity (P < 0.002). In males' heads, 0.4 mM Cu increased the AChE activity (P < 0.01). In adults' bodies, Cuinhibited the activity in both sexes, but with greater effectiveness in males (0.1 to 1 mM) than in females (1 mM). Regarding GST activity, 0.1 mM Cuincreased, but 1 mM decrease GST in larvae. In the head of flies, Cudecreased the GST activity at intermediate (0.4 mM) and increased GST at the highest concentration (1 mM) in males. In the bodies, the effect of Cuwas similar. In conclusion, Cuexposure in D. melanogaster disrupted locomotion and enzymatic parameters that can be related to changes in AChE and in the detoxifying GST enzyme.