Bovine SNP array-based genetic assessment of American plains bison at American Prairie

Abstract American plains bison (Bison bison bison, bison hereafter) experienced an extreme demographic bottleneck in the late 1800s. The species has since rebounded but is primarily managed as small and isolated herds due to habitat and sociopolitical limitations. Thus, reintroducing bison and allowing herds to achieve as much of their natural dynamics as possible is a major conservation goal. Concerns about genetic diversity loss in small, isolated herds and the persistence of cattle-origin variants from historical crossbreeding efforts have made genetic analysis an important part of bison conservation. The limitations of the current conservation genetic tools which are based on traditional markers such as microsatellites and mitochondrial DNA sequences, may be overcome with genome-wide genotyping panels commonly developed for agricultural species. Bison reintroduction in the grasslands at American Prairie began in 2005. Genetic analysis on these herds has yet to be conducted. We used the Illumina 777K Bovine genotyping panel to obtain data from 197 bison and 179 domestic cows to understand the current population genetic state of bison at American Prairie and gain insight on cattle (Bos taurus) introgression. Overall, bison at American Prairie currently have relatively high genetic diversity, low inbreeding, and no obvious signs of cattle introgression. A more comprehensive evaluation of introgression, likely including whole-genome sequence data, would clarify this finding. These results can serve as a baseline for future comparison as part of a genetic monitoring framework.