Application of Transcriptomics Dose-Response Modeling to Risk-Based Prioritization of Contaminants Detected in Tributaries of the North American Great Lakes [P. promelas]

Among these, there were 140 chemicals for which no empirical toxicity data were available to support prioritization. The aim of the present study was to generate transcriptomic points of departure (tPODs) for 10 of these compounds and demonstrate how they could be applied in a screening-level prioritization.

Organisms representing three different trophic levels of the aquatic food-web (Pimephales promelas – secondary consumer, Daphnia magna-primary consumer, and R. subcapitata-primary producer). were exposed for 24 h to a ½-log dilution series of nominal exposure concentrations typically ranging from 66.7 to 0.021 µM of each chemical. In addition to observations of apical effects such as survival and morphology, whole body transcriptomic responses to each chemical were evaluated with targeted analysis using TempO-seq for P. promelas and D. magna and non-targeted full RNA-seq for R. subcapitata.