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

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 be used to 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 FST values ranging from 0.1804 to 0.65, pairwise DXY 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 west 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. Overall, our data suggest that considering genetically diverged 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 as ‘unique’ units without evidence of adaptive differentiation could be problematic for their conservation. We effectively demonstrate how genomic information can guide practical encourage managers to incorporate genomic information into conservation planning, especially when declining species are represented by multiple isolated populations.利用遗传信息制定并实施保护计划，对维持生物多样性与生态系统韧性至关重要。评估残存种群内部及种群间的遗传变异（genetic variability），可为自然种群与易地放归种群（translocated populations）的管理提供依据，以最大化物种的适应潜力、减轻近交的负面影响，进而降低灭绝风险。本研究利用简化基因组测序（reduced representation sequencing），对澳大利亚特有濒危有袋类——金袋狸（Isoodon auratus）开展遗传评估。目前公认的该物种类群包含3个亚种，分布于多个自然种群及易地放归种群中。在确认金袋狸与两个近缘类群——褐腹袋狸（I. fusciventer）和大袋狸（I. macrourus）的遗传分化性后，我们在金袋狸内部鉴定出4个遗传聚类群。这些聚类群间存在显著的遗传分化：两两固定指数（pairwise FST）取值范围为0.1804至0.65，两两核苷酸差异数（pairwise DXY）取值范围为0.1至0.168，这反映出部分近海岛屿种群的长期隔离以及遗传漂变（genetic drift）的影响。西金伯利地区的大陆自然种群，相较于自然岛屿种群与易地放归岛屿种群，拥有最高的遗传多样性，且对整体等位基因多样性与基因多样性的贡献最大。一个被易地放归至北领地（Northern Territory）古鲁武鲁岛（Guluwuru Island）的种群，其遗传多样性最低。总体而言，我们的研究结果表明：遗传分化显著的岛屿种群可能因遗传漂变而呈现遗传独特性，在保护工作中考虑遗传多样性时需重视这一点——若将缺乏适应分化证据的种群视为‘独特’保护单元，可能会对该物种的保护产生不利影响。本研究清晰展示了基因组信息如何为保护实践提供指导，并呼吁管理者将基因组信息纳入保护规划，尤其针对那些由多个孤立种群构成的衰退物种。