Transcriptomic Dose-Response Analysis in Zebrafish Embryos to Estimate Aquatic Toxicity of Plasticizers and Plastic Monomers

Current toxicity tests have high monetary costs, efficiency issues and ethical concerns. New approach methodologies, such as transcriptomic dose response modelling (TDRM), are increasingly being used to address these issues. This thesis aimed to combine the TDRM method with an acute zebrafish embryo model exposure to determine effective concentrations for chemicals of concern (plasticizers and plastic monomers). We hypothesized that the TDRM methodology would be more sensitive and informative than traditional apical endpoints derived from acute fish exposures. We found that transcriptomic endpoints were more sensitive than apical endpoints for the majority of chemicals tested. However, several challenges related to experimental design and RNA sequencing were encountered and recommendations were given for future studies to address these challenges. Overall, the TDRM methodology, when combined with the zebrafish embryo model, shows promise as an effective tool for screening and prioritizing chemicals of concern.