The Effect of Paraphenylenediamine on NAT2 Gene Expression, Behavior, and L3 Larvae Counts in Drosophila Melanogaster

Abstract

Paraphenylenediamine (PPD) is an arylamine commonly found in permanent hair dye. Arylamines are known carcinogens that are detoxified by N-acetyltransferase 2 (NAT2). The NAT2 gene is located in all cells of the body, however, expression of the NAT2 protein is localized to the gastrointestinal tract and liver. Current research shows a correlation between the NAT2 slow acetylator phenotype and bladder cancer. Similar to the NAT2 protein, the NAT1 protein detoxifies carcinogens within the body, however, it is localized to the skin. The NAT2 protein has a three to four-fold higher affinity for PPD than the NAT1 protein within the human body, leading to an increased risk for bladder cancer. The goal of this research was to analyze the impact of PPD exposure on NAT2 expression and mechanosensation within the larvae of Drosophila melanogaster. For this study, larvae were exposed to either control media, or media that contained 2.2% PPD for 24 hours. Following the 24 hour exposure, RT-qPCR was performed to measure the expression of the NAT2 gene and a mechanosensation assay was performed to determine effects on motor function. We predict from this research that the expression of the NAT2 gene will increase in the larvae exposed to PPD. This is because there will be a higher need for detoxification. Along with this, we predict that larvae exposed to PPD will show impaired motor function due to the chemical’s toxicity.