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. The results were as follows:1.The developmental time of D. melanogaster developed in different copper contaminated mediums was observed. It shows that the copper-contaminated food resulted in delayed fly development, especially within the larval stages, and the body lengths of the larvae in the copper-treated groups were significantly shorter than those in the control groups despite undergoing the same developmental period. However, providing that the larvae pupated, it took approximately the same amount of time to metamorphose, except for the larvae in the 320-mg L-1 copper groups, which took longer to metamorphose into adults. Furthermore, too much copper also resulted in the failure of pupation Our study shows that low doses of copper generally have no lethal effects on D. melanogaster. However, high concentrations, such as 320 mg L-1 copper, significantly affect fly development and viability, and the larval developmental time is extremely extended.2 , The proteins of the third instar larvae the new eclosion adults from different copper treated groups was then extracted and examined. The proteins of the third instar larvae were examined by polyacrylamide gel electrophoresis (PAGE) ,it shows that copper culturing damaged larvae protein expression and resulted in the loss of smaller-molecular-weight proteins, but there was a stronger protein band in the low copper concentration groups than in the control groups. The protein from the new eclosion adults was then extracted and examined. Our study shows that the proteins from the adults that developed in different copper-contaminated mediums did not change significantly.3 The esterase isozymes (EST) activity in the third instar larvae was investigated. Most of the subunits of the EST gradually became weaker as the concentration of copper increased, while a few of the low-molecular-weight subunits were lost. However, an additional band appeared in the low copper concentration groups, and appeared only faintly in the 160-mg L-1 group.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.