Whole-genome resequencing data support a single introduction of the invasive white pine sawfly, Diprion similis
Whole-genome resequencing data support a single introduction of the invasive white pine sawfly, Diprion similis
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DOI：
10.1093/jhered/esad012
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发表时间：
2023-04-22
影响因子：
3.1
通讯作者：
Linnen，Catherine R.
中科院分区：
文献类型：
--
作者：
Davis，Jeremy S.;Sim，Sheina;Linnen，Catherine R.
生物学的引入是一种无意的“自然实验”，它为进化过程提供了独特的见解。入侵植食性昆虫对研究适应的进化生物学家特别感兴趣，因为引入通常需要快速适应新的寄主植物。然而，入侵种群的适应潜力可能会受到遗传多样性减少的限制--这一问题被称为“入侵的遗传悖论”。这一悖论的一个潜在解决方案是，如果存在支持入侵种群遗传变异的多个入侵浪潮。评估这一假设需要描述入侵范围内的遗传变异和种群结构。为此，我们组装了一个参考基因组，并描述了引进的白松叶蜂Diprion similis的遗传变异模式。该物种于1914年被引入北美，在那里它迅速地在细针东方白松(Pinus Strobus)上定居，使其成为研究对新环境的适应的理想入侵系统。为了评估多重导入的证据，我们生成了64D的全基因组重测序数据。在北美范围内对相似的雌性动物进行了抽样。基于模型和无模型的聚类分析都支持北美的单一群体D。相似之处。在这个群体中，我们发现了按距离隔离的证据，以及随着距离假设的引入地点的距离而杂合度下降的模式。总而言之，这些结果支持一次单一介绍活动。我们考虑了这些发现对侵袭的基因悖论的影响，并讨论了未来研究的优先事项。SIMIIS，一个很有前途的入侵生物学模式系统。
Biological introductions are unintended “natural experiments” that provide unique insights into evolutionary processes. Invasive phytophagous insects are of particular interest to evolutionary biologists studying adaptation, as introductions often require rapid adaptation to novel host plants. However, adaptive potential of invasive populations may be limited by reduced genetic diversity—a problem known as the “genetic paradox of invasions.” One potential solution to this paradox is if there are multiple invasive waves that bolster genetic variation in invasive populations. Evaluating this hypothesis requires characterizing genetic variation and population structure in the invaded range. To this end, we assemble a reference genome and describe patterns of genetic variation in the introduced white pine sawfly,Diprion similis. This species was introduced to North America in 1914, where it has rapidly colonized the thin-needled eastern white pine (Pinus strobus), making it an ideal invasion system for studying adaptation to novel environments. To evaluate evidence of multiple introductions, we generated whole-genome resequencing data for 64D. similisfemales sampled across the North American range. Both model-based and model-free clustering analyses supported a single population for North AmericanD. similis. Within this population, we found evidence of isolation-by-distance and a pattern of declining heterozygosity with distance from the hypothesized introduction site. Together, these results support a single-introduction event. We consider implications of these findings for the genetic paradox of invasion and discuss priorities for future research inD. similis, a promising model system for invasion biology.