Refining Management Units through Genomics

Management unit delineation can help in the development of targeted strategies for species conservation.  Typically, neutral genetic data are used to group together genetically similar populations, under the assumption that those populations are headed down the same evolutionary pathway.  However, it is uncertain whether that assumption is correct.  Are we protecting true evolutionary lineages?  Genetic data from 28 spawning populations of lake sturgeon in the Hudson Bay, Great Lakes, and Mississippi River were collected at 12 microsatellite loci.  Ten population clusters were identified: three clusters in Hudson Bay, six clusters in the Great Lakes, and one cluster in the Mississippi River.  To test whether or not these clusters represent different evolutionary lineages, next-generation sequencing was conducted to compare individuals from each of the ten clusters.  Based on the mitochondrial genome, two clusters were identified.  One of those clusters likely corresponds to use of the Mississippian refugium during glaciation, while the other cluster likely used the Missourian refugium.  Further analyses of the 11,000+ SNPs that were identified will elucidate adaptive differences among the clusters.