Identifying Stressors in Minnesota Lakes Using cDNA Microarrays

Perfluorinated chemicals (PFCs) are common stressors in aquatic ecosystems around the world.  However, relatively little research has been conducted to assess whether PFC exposure in aquatic ecosystem affects the physiological condition of resident organisms.  To assess the effects of PFCs in aquatic ecosystems, gene expression patterns in largemouth bass were quantified across a PFC exposure gradient in lakes throughout the Twin Cities Metro Area (TCMA) in Minnesota using a 15,000 gene cDNA microarray.  Gene expression patterns in largemouth bass corresponded closely with PFC concentrations. Similarly, largemouth bass with high PFC tissue concentrations consistently exhibited changes in the expression of genes related to lipid metabolism, energy production, RNA processing, protein production/degradation and contaminant detoxification—all of which are consistent with responses observed in previous laboratory studies with PFCs.  Taken together, these results suggest that PFCs are potentially influencing the physiological condition of largemouth bass in several lakes throughout the TCMA and that cDNA microarrays may provide a valuable tool to assess the relative contribution of different stressors in aquatic ecosystems. However, given the wide range of genes that were differentially expressed across TCMA lakes, it is unlikely that PFCs are the only stressors affecting largemouth bass in these systems.