Project description:The mechanistic basis of resistance of vertebrate populations to contaminants, including Atlantic tomcod from the Hudson River (HR) to polychlorinated biphenyls (PCBs), is unknown. HR tomcod exhibited variants in the aryl hydrocarbon receptor 2 (AHR2) that were nearly absent elsewhere. In ligand-binding assays, AHR2-1 protein (common in the HR) was impaired as compared to widespread AHR2-2 in binding TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) and in driving expression in reporter gene assays in AHR-deficient cells treated with TCDD or PCB126. We identified a six-base deletion in AHR2 as the basis of resistance and suggest that the HR population has undergone rapid evolution, probably due to contaminant exposure. This mechanistic basis of resistance in a vertebrate population provides evidence of evolutionary change due to selective pressure at a single locus.
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature.
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature.
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature.