Conservation implications of limited genetic diversity and population structure in Tasmanian devils (Sarcophilus harrisii)

Abstract

Tasmanian devils face a combination of threats to persistence, including devil facial tumor disease (DFTD), an epidemic transmissible cancer. We used RAD sequencing to investigate genome-wide patterns of genetic diversity and geographic population structure. Consistent with previous results, we found very low genetic diversity in the species as a whole, and we detected two broad genetic clusters occupying the northwestern portion of the range, and the central and eastern portions. However, these two groups overlap across a broad geographic area, and differentiation between them is modest (\({{F}_{\text{ST}}}\) = 0.1081). Our results refine the geographic extent of the zone of mixed ancestry and substructure within it, potentially informing management of genetic variation that existed in pre-diseased populations of the species. DFTD has spread across both genetic clusters, but recent evidence points to a genomic response to selection imposed by DFTD. Any allelic variation for resistance to DFTD may be able to spread across the devil population under selection by DFTD, and/or be present as standing variation in both genetic regions.

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Acknowledgements

Funding for our work was provided by NSF grant DEB-1316549, NIH grant P30GM03324, and an Australian Research Council Future Fellowship to MJ (FT100100250). We thank the University of Idaho Institute for Bioinformatics and Evolutionary Studies for technical support and resources in the Genomics and Computational Resources Cores; Tamara Max, Mike Miller, Sean O’Rourke, Daryl Trumbo, and Doug Turnbull for assistance with sequencing. We are grateful to Amanda Stalhke, Lisette Waits, and three anonymous reviewers for comments on the manuscript.

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Correspondence to Paul Hohenlohe.

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Hendricks, S., Epstein, B., Schönfeld, B. et al. Conservation implications of limited genetic diversity and population structure in Tasmanian devils (Sarcophilus harrisii). Conserv Genet 18, 977–982 (2017). https://doi.org/10.1007/s10592-017-0939-5

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Keywords

  • Conservation genomics
  • Devil facial tumor disease
  • Gene flow
  • Population bottlenecks
  • RAD sequencing
  • Transmissible cancer