Development and use of microsatellite DNA loci for genetic ecotoxicological studies of the fathead minnow (Pimephales promelas).

The development of new DNA technologies has increased the opportunities to study the effect of genetic variation as a factor in selection, resistance, and fitness of individuals and populations. Genetic composition affects the evolutionary potential of an organism; however, whether genetic variation has a role in adaptation and survival due to chemical stress is still under debate. The strategy of measuring such variation should be based on the desired number of loci needed and degree of polymorphism at each locus. Microsatellite DNA loci (also known as Simple Tandem Repeats, STRs) have among the highest levels of variation within most eukaryotic genomes. Methods to determine the high levels of variation in individuals and populations have become more refined, making DNA-based studies in ecotoxicology more feasible. Herein, we describe the general characteristics of microsatellite DNA loci, their isolation, and their applications to toxicological studies using the fathead minnow (Pimephales promelas) as a focal species.