Populations of the Atlantic killifish (Fundulus heteroclitus) inhabiting urban estuaries have rapidly and repeatedly evolved tolerance to extreme pollution stress, yet the genetic changes that enabled this adaptive tolerance are unknown. This grant will facilitate sequencing the full killifish genome, and re-sequencing of genomes from many sensitive and tolerant populations, to enable discovery of the genetic changes that facilitated tolerance to human pollutants, and address whether there are a few or many genetic variants that confer tolerance or sensitivity to pollution among the many different populations inhabiting polluted sites.
A major ambition of both evolutionary biology and medical genetics is to identify the genetic variants within and among populations that contribute to an individual's tolerance to stress or disease. For example, human individuals vary in their sensitivity to disease and environmental pollutants, and a portion of this variation has a genetic basis. Studies of the genomic changes in killifish exposed to pollutants provide an excellent opportunity to discover the genetic basis of individual sensitivity to common environmental pollutants in a vertebrate animal that shares many traits with humans. This research could identify genetic variants that contribute to human sensitivity to environmental pollutant exposures and also offer detailed insight into fundamental mechanisms of the evolutionary process.