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Wednesday, June 6, 2007 - 8:15 AM
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Genetic evidence for restricted gene flow between cutthroat trout spawning populations in Yellowstone Lake
David J. Janetski1, Dennis Shiozawa2, and R. Paul Evans2. (1) Department of Biological Sciences, University of Notre Dame, 292 Galvin, Notre Dame, IN 46556-0369, (2) Integrative Biology, Brigham Young University, 147-A WIDB, Provo, UT 84602
Patterns of gene flow and reproductive isolation have important implications for the development of local adaptations and ultimately species evolution. Local adaptation allows for increased reproductive success in populations; therefore, maintaining natural levels of gene flow and isolation are vital conservation priorities. A highly-valued population that has recently become at risk due to disease and invasive predators is the Yellowstone cutthroat trout of Yellowstone Lake, Yellowstone National Park. We investigated the potential for local adaptation between cutthroat trout spawning locations (i.e., tributaries) in Yellowstone Lake by quantifying population substructure and gene flow. Molecular methods were used to amplify two mitochondrial DNA genes and six microsatellite loci from 509 individuals covering 15 locations. These data were analyzed using a variety of traditional (e.g., F-statistics) and modern (e.g., nested clade analysis) techniques. Strong evidence for restricted gene flow was detected with nested clade analysis, indicating a degree of reproductive isolation at two spawning locations. This is the first reported molecular evidence for restricted gene flow between spawning populations in Yellowstone Lake. This finding may have important conservation implications for this imperiled population and we recommend current population dynamics be maintained in order to sustain the natural evolutionary processes of the fishery.