Meeting Abstract
Heavy metal pollution stemming from mining activities has profound biological effects, causing reproductive damage, behavioral changes, and increased mortality on an individual level, with cascading consequences for populations and ecosystems. The Tar Creek Superfund site in the Tri-State Mining District of Kansas, Missouri, and Oklahoma was declared due to heavy metal pollution from acidic mine runoff in the Tar Creek watershed. Resident populations of Western mosquitofish (Gambusia affinis) provide an opportunity to study organismal and evolutionary responses to heavy metal pollution at all levels of organization. Mosquitofish are the dominant species in polluted sections of Tar Creek and also occur in numerous proximate, uncontaminated watersheds, facilitating comparative analyses. We used high-throughput elemental profiling and RNA-sequencing in gill, liver, and brain tissues to address basic questions about organismal responses to heavy metal stress: 1) how does the extent of metal accumulation vary across tissues in G. affinis?; 2) how does metal accumulation differ between contaminated and uncontaminated populations of G. affinis?; and 3) what genes are differentially expressed between contaminated and uncontaminated populations? Future work will discern whether these observed gene expression differences are due to evolution or plasticity, which will allow us to investigate how heavy metal pollution might impact rapid evolutionary responses and understand the mechanisms that have allowed G. affinis to inhabit extreme environments.
