Diversity in the Toll-like receptor genes of the Tasmanian devil (Sarcophilus harrisii)

The Tasmanian devil is an endangered marsupial species that has survived several historical bottlenecks and now has low genetic diversity. Here we characterize the Toll-like receptor (TLR) genes and their diversity in the Tasmanian devil. TLRs are a key innate immune gene family found in all animals. Ten TLR genes were identified in the Tasmanian devil genome. Unusually low levels of diversity were found in 25 devils from across Tasmania. We found two alleles at TLR2, TLR3 and TLR6. The other seven genes were monomorphic. The insurance population, which safeguards the species from extinction, has successfully managed to capture all of these TLR alleles, but concerns remain for the long-term survival of this species.The wild devil samples used in this study were kindly provided by Menna Jones and Rodrigo Hamede from the School of Zoology at the University of Tasmania and the Save the Tasmanian Devil Program. We thank Carolyn Hogg from the Zoo and Aquarium Association for providing captive samples from the Save the Tasmanian Devil Insurance Program. This work was funded by an Australian Research Council grant to KB. KB is supported by an ARC Future Fellowship