Genetic structure of raccoons in eastern North America based on mtDNA: implications for subspecies designation and rabies disease dynamics

摘要

Subspecific designations are useful for wildlife management when they represent real barriers to gene flow. In this study, we assess genetic partitioning of mitochondrial DNA control region variation to determine if the structuring is congruent with morphologically defined subspecies of the common raccoon (Procyon lotor (L., 1758)). Mitochondrial control region sequences were analyzed within and among four subspecies (Procyon lotor elucus Bangs, 1898, Procyon lotor lotor (L., 1758), Procyon lotor hirtus Nelson and Goldman, 1930, and Procyon lotor varius Nelson and Goldman, 1930) that occur along the eastern seaboard of North America through to the central United States. This identified 76 haplotypes, 59 of which were specific to one of the four ranges, while only 1 haplotype was wide-spread. Phylogenetic analysis revealed three distinct lineages: one found primarily in Florida, one along the eastern seaboard, and the third predominantly to the west of the Mississippi River. These lineages likely diverged during the Pleistocene, as a result of rising sea levels creating barriers to gene flow. The range of P. l. elucus is still primarily one lineage supporting the subspecific designation; however, there is considerable lineage mixing across the ranges of P. l. hirtus, P. l. lotor, and P. l. varius, suggesting that they be synonymized to P. l. lotor. While some of these subspecies designations are not supported, we have found that landscape attributes affect gene flow, which can be of use in informing rabies management.