The impacts of sex and genetic background on the response of Drosophila melanogaster to essential and non-essential metal toxicity.

Abstract

The following thesis investigates the impact of biological sex and genetic background on the response to copper and nickel toxicity in Drosophila melanogaster. Sex differences are historically understudied across biology despite significantly impacting metabolism, disease, and response to toxicants like toxic metals. Understanding the sexual dimorphism of metal toxicity is important for understanding the impact of metal pollution on the surrounding community and environment of mining communities around the globe. I predict that biological sex and genetic background will have a significant impact on the fly response to copper and nickel toxicity. I used the model organism D. melanogaster in multiple lethality assays to determine how four different isogenic lines and the two sexes respond to both copper and nickel toxicity. I performed multiple lethality assays using various concentrations of nickel and copper which concluded that sex and genetic background had a significant impact on the fly response to metal toxicity. The results of the lethality assays were supported by a subsequent starvation assay and measurement of ingested nickel content by inductively-coupled mass spectrometry (ICP-MS). The results of both the lethality assays and measurement of ingested nickel suggest that the common general metal response pathway which is responsible for maintaining metal homeostasis is significantly impacted by sex and genetic background.