Population genetics and invasion history of the European Starling across Aotearoa, New Zealand: whole genome resequencing of New Zealand starlings

The samples uploaded in this project is the whole genome resequencing data that was generated for some New Zealand caught individuals.The expansion of human settlements over the past few centuries is responsible for an unprecedented number of invasive species introductions globally. An important component of biological invasion management is understanding how introduction history and post-introduction processes have jointly shaped present-day distributions and patterns of population structure, diversity, and adaptation. One example of a successful invader is the European starling (Sturnus vulgaris), which was intentionally introduced to numerous countries in the 19th century, including Aotearoa New Zealand, where it has become firmly established. We used reduced-representation sequencing to characterise the genetic population structure of the European starling in New Zealand, and compare the population structure to that present in sampling locations in the native range and invasive Australian range. We found that population structure and genetic diversity patterns suggested restricted gene flow from the majority of New Zealand to the northmost sampling location (Auckland). We also profiled genetic bottlenecks and shared outlier genomic regions, which supported historical accounts of translocations between both Australian subpopulations and New Zealand, and provided evidence of which translocation events were more likely to have been successful. Using these results as well as historic demographic patterns, we demonstrate how genomic analysis complements even well-documented invasion histories to better understand invasion processes, with direct implication for understanding contemporary gene flow and informing invasion management.

本项目上传的样本为针对部分新西兰捕获个体生成的全基因组重测序数据（whole genome resequencing data）。近几个世纪以来人类定居点的扩张，在全球范围内引发了史无前例的外来物种引入事件。生物入侵管理的一项核心内容，便是解析引入历史与引入后过程如何共同塑造了物种种群结构、多样性与适应性的现今分布模式。成功入侵物种的典型案例之一为欧洲椋鸟（Sturnus vulgaris），该物种于19世纪被人为引入诸多国家，包括新西兰（Aotearoa New Zealand），目前已在当地稳固定居。本研究采用简化基因组测序（reduced-representation sequencing）技术，解析了新西兰境内欧洲椋鸟的遗传种群结构，并将其与该物种原生分布区以及入侵性澳大利亚分布区的采样位点种群结构进行对比。研究结果显示，种群结构与遗传多样性模式表明，新西兰大部分区域至最北端采样点奥克兰（Auckland）之间的基因流受到限制。本研究同时对遗传瓶颈与共有基因组异常区域进行了分析，结果佐证了澳大利亚亚种群与新西兰之间曾发生种群转移事件的历史记载，并为哪些转移事件更易获得成功提供了证据支持。结合上述研究结果与历史种群动态模式，本研究阐明了基因组分析如何能够补充甚至完善已有详实记录的入侵历史，从而更深入地解析入侵过程，这对于理解当代基因流以及为入侵管理提供决策参考均具有直接的实践意义。