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Dr. Mark Jordan
Department of Biology
Indiana University – Purdue University Fort Wayne
Geographic analysis of genetic lineages within species has proven to be a powerful approach for understanding patterns of evolutionary diversification and can guide the conservation and management of imperiled species. The Blanding’s turtle (Emys blandingii) is an interesting subject for this type of analysis due to its wide geographic distribution and current status as threatened and endangered throughout most of its range. Previous studies have suggested that there may be subpopulations within the species that are associated with both the Appalachian Mountains and recent glacial history. To date, there has been no range-wide genetic analysis of the species based on mitochondrial DNA. I analyzed DNA sequence variation in two mitochondrial loci [control region (DES) and NADH dehydrogenase 4 (ND4)]. The polymerase chain reaction was used to amplify the loci prior to sequence analysis. Sequencing the segment yielded a divergence of 0.46% in 659 bases of control region (n = 30) and no divergence in 760 bases of ND4 (n = 15) from turtles sampled between Nebraska and Nova Scotia. By comparison, in only seven E. marmorata, sequence divergences were 1.7% and 3.1% for these loci, respectively (Spinks and Shaffer 2005, Molecular Ecology 14:2047-2064). Overall, the sequence variability observed may result from a combination of low mutation rates within the mitochondrial genome and a bottleneck at some point prior to post-glacial range expansion. While preliminary analyses suggest that there may be two broadly distributed subpopulations based on the minimal polymorphisms within DES further characterization of mitochondrial sequences is needed to support this interpretation.
Biology | Life Sciences
Millspaw, Natalie, "Low Genetic Variability Across the Geographic Range of the Blanding’s Turtle (Emys blandingii)" (2014). 2014 IPFW Student Research and Creative Endeavor Symposium. 27.