Population genomic diversity and structure in the golden bandicoot: a history of isolation, extirpation, and conservation

Kate Rick; Margaret Byrne; Skye Cameron; Steve J B Cooper; Judy Dunlop; Brydie Hill; Cheryl Lohr; Nicola J Mitchell; Craig Moritz; Kenny J Travouillon; Brenton von Takach; Kym Ottewell

doi:10.1038/s41437-023-00653-2

Population genomic diversity and structure in the golden bandicoot: a history of isolation, extirpation, and conservation

Heredity (Edinb). 2023 Dec;131(5-6):374-386. doi: 10.1038/s41437-023-00653-2. Epub 2023 Oct 8.

Authors

Kate Rick¹, Margaret Byrne², Skye Cameron³, Steve J B Cooper^{4

5}, Judy Dunlop⁶, Brydie Hill⁷, Cheryl Lohr², Nicola J Mitchell⁸, Craig Moritz⁹, Kenny J Travouillon¹⁰, Brenton von Takach¹¹, Kym Ottewell^{8

2}

Affiliations

¹ School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia. Kate.Rick@research.uwa.edu.au.
² Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Kensington, WA, 6152, Australia.
³ Australian Wildlife Conservancy, Level 2 322 Hay Street, Subiaco, WA, 6008, Australia.
⁴ South Australian Museum, North Terrace, Adelaide, SA, 5000, Australia.
⁵ Department of Ecology and Evolutionary Biology, Environment Institute, School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia.
⁶ School of Agriculture and Environment, The University of Western Australia, Crawley, WA, 6009, Australia.
⁷ Flora and Fauna Division, Department of Environment, Parks and Water Security, Northern Territory Government, Darwin, NT, Australia.
⁸ School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.
⁹ Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia.
¹⁰ Collections and Research, Western Australian Museum, Welshpool, WA, 6106, Australia.
¹¹ School of Molecular and Life Sciences, Curtin University, Perth, WA, 6102, Australia.

Abstract

Using genetic information to develop and implement conservation programs is vital for maintaining biodiversity and ecosystem resilience. Evaluation of the genetic variability within and among remnant populations can inform management of both natural and translocated populations to maximise species' adaptive potential, mitigate negative impacts of inbreeding, and subsequently minimise risk of extinction. Here we use reduced representation sequencing to undertake a genetic assessment of the golden bandicoot (Isoodon auratus), a threatened marsupial endemic to Australia. The currently recognised taxon consists of three subspecies distributed among multiple natural and translocated populations. After confirming the genetic distinctiveness of I. auratus from two closely related taxa, I. fusciventer and I. macrourus, we identified four genetic clusters within I. auratus. These clusters exhibited substantial genetic differentiation (pairwise F_ST values ranging from 0.18 to 0.65, pairwise D_XY ranging from 0.1 to 0.168), reflecting long-term isolation of some populations on offshore islands and the influence of genetic drift. Mainland natural populations in the Kimberley region had the highest genetic diversity and the largest contribution to overall allelic and gene diversity compared to both natural and translocated island populations. A population translocated to Guluwuru Island in the Northern Territory had the lowest genetic diversity. Our data suggest that island populations can appear genetically unique due to genetic drift and this needs to be taken into account when considering genetic diversity in conservation efforts to maintain overall genetic diversity of the species. We effectively demonstrate how genomic information can guide practical conservation planning, especially when declining species are represented by multiple isolated populations.

MeSH terms

Conservation of Natural Resources
Ecosystem
Genetic Drift
Genetic Variation*
Genetics, Population*
Metagenomics