Several sites along the Elizabeth River (VA, USA) have been contaminated
with creosote, a complex mixture made from coal tar. Surprisingly, populations of Atlantic
killifish, a common intertidal minnow, can be found living in these highly contaminated estuaries.
After years of study, we now know that these fish have actually evolved a tolerance to the primary
components of creosote, a class of chemicals known as polycyclic aromatic hydrocarbons (PAHs).
More specifically, this adaptation protects killifish embryos from developing severe deformities
and other negative effects of PAHs, even after exposures to typically lethal concentrations. Recent
studies have shown that there are mutations in the genome of these killifish that likely explain how
they can survive in such extreme conditions. However, we still do not understand how these
changes impact the response of adapted killifish to PAH exposures or other natural, but stressful
changes in their environment. This project aims to 1) identify baseline differences in gene
expression between adapted and naïve populations of killifish throughout development, 2) monitor
genes suspected of a role in tolerance to PAHs for their activity during exposures, and 3) assess
how adaptations protective against PAH toxicity alter an organism’s response to other fluctuations
in their environment.
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