Genetic variation and leprosy distribution in nine-banded armadillos

Genetic, ecological, and environmental variation within and among populations of hosts and pathogens can influence local susceptibility of hosts and transmission rates of pathogens. These complex interactions can lead to geographic variation in the prevalence of pathogens. The interaction between leprosy and nine-banded armadillos in the southeastern U.S. provides an opportunity to examine the genetic, ecological, and environmental factors contributing to the variation in pathogen prevalence on a large geographic scale. Using genotypic data for loci associated with the immune response to leprosy and for anonymous loci, we have assessed the population structure of armadillo populations across the southern U.S. Additional statistical tests were used to assess any significant differences between functional and anonymous loci that indicate selection. Our results suggest that local adaptation does not influence the geographic distribution of leprosy in armadillo populations and that very little genetic variation can be attributed to differences among host populations