The Investigation of Multigenerational and Transgenerational Trichloroethylene Toxicity using the Zebrafish (Danio Rerio)

Abstract

Multigenerational and transgenerational toxicology studies evaluate the persistence of toxicity in progeny of individuals exposed to a toxicant. For many toxicants, non-genetic mechanisms, especially the alteration of the epigenome, are suspected to cause transgenerational toxicity. TCE is a legacy chemical with known adverse effects; however, the epigenetic toxicity is not well characterized. This thesis reviews the concepts of multi- and transgenerational toxicity, mechanisms of epigenetic toxicity, and the role of zebrafish in studying epigenetic, multigenerational, and transgenerational toxicity. In the second chapter, the zebrafish (Danio rerio) model is used to characterize changes in progeny directly and indirectly exposed to TCE. The multigenerational progeny (F1), or those who had direct exposure to TCE as gametes, demonstrated changes in morphology, had an increased heart rate, and changes in locomotion and turning behaviors as compared to the controls. The transgenerational progeny (F2), those with no direct exposure to TCE, demonstrated changes in morphology, had decreased heart rate and changes in locomotion, path shape, and turning behavior. These results support the need for further investigation into the epigenetic, multigenerational, and transgenerational effects of TCE exposure.