Methylmercury and diphenyl diselenide interactions in Drosophila melanogaster: effects on development, behavior, and Hg levels

Methylmercury (MeHg) is a highly toxic environmental pollutant which binds with a high affinity to selenol groups. In view of this, seleno-compounds have been investigated as MeHg antidotes. In the present study, we evaluated the effects of the co-exposure to MeHg and the seleno-compound diphenyl diselenide (PhSe) 2 on Drosophila melanogaster . We measured the survival rate, developmental survival, locomotor ability, reactive oxygen species (ROS) production, and Hg levels in D. melanogaster exposed to MeHg and/or (PhSe) 2 in the food. Exposure to MeHg caused a reduction in the survival rate, developmental survival, and locomotion in D. melanogaster . In addition, MeHg increased the ROS production and mercury levels in flies. The co-exposure to MeHg and (PhSe) 2 did not prevent the toxic effects of MeHg in D. melanogaster . On the contrary, the co-exposure enhanced the toxic effects on the locomotor ability and developmental survival. This effect may be explained by the fact that the co-exposure increased the Hg levels in body when compared to flies exposed only to MeHg, suggesting that MeHg and (PhSe) 2 interaction may increase Hg body burden in D. melanogaster which could contribute for the increased toxicity observed in the co-exposure.