Evaluating the impacts of metal exposure concentration and duration on juvenile fish transcriptomes

Our research used a combination of laboratory-based acute aqueous metals exposures and RNA-sequencing technologies to identify a gene-based means to extrapolate metals toxicity across a range of fish taxa. For Phase 1 of our project, we compared transcriptome changes in caudal fin, gill and liver of juvenile Rainbow trout (Oncorhynchus mykiss) exposed to cadmium (Cd), copper (Cu), or zinc (Zn) at 17, or 50% of LC50 concentrations for 24 and 96 hours to controls. These experiments allowed us to test for conserved responses to the metal exposures, and to test which metal produced the most coherent gene expression profile indicative of a defined mode of action. During Phase 2, we exposed juvenile Chinook salmon (Oncorhynchus tshawytscha) to the selected metal (Zn) to begin to ascertain the extent to which the mode of action identified was conserved among salmonids.