In recent years, there have been tens of thousands of waterfowl mortalities in Wisconsin and Minnesota. An invasive species of snail, Bithynia tentaculata, is a host for the trematode parasites (Cyathocotyle bushiensis and Sphaeridiotrema globulus) that have caused these deaths. A microsatellite-enriched genomic library was detected using DNA from a B. tentaculata specimen from Lake Onalaska (Pool 7 of the Upper Mississippi River). Seven polymorphic microsatellite loci were used to genotype snails collected from Lake Butte des Morts, Shawano Lake, and Lake Onalaska in Wisconsin, as well as Lake Winnibigoshish in Minnesota. The genetic diversity of each population was measured as the number of alleles detected at each locus (NA), observed and expected heterozygosity (HO and HE), and allelic richness (AR). Populations were then differentiated by pairwise FST values, and the number of genetically distinct populations (K) was estimated. A consensus tree showing the relationship between geographical populations was created using matrices of Nei's distance after repeatedly subsampling (bootstrapping) the data. Cluster analysis showed the genetic data from these snails was best explained by two groups, one containing the eastern Wisconsin populations and the other containing snails from Lake Onalaska and Lake Winnibigoshish. Furthermore, genetic distance and FST data suggests that the population of B. tentaculata in Shawano Lake likely founded the population in Lake Butte des Morts, which then contributed individuals to both Lake Onalaska and Lake Winnibigoshish.
Robert E. Sorensen
Bradley J. Cook
John D. Krenz
Date of Degree
Master of Science (MS)
Science, Engineering and Technology
Whalen, Sarah J., "Analysis of the Genetic Structure of Bithynia tentaculata Snail Populations in Wisconsin and Minnesota" (2011). All Theses, Dissertations, and Other Capstone Projects. 18.
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