Evolutionary origins of genomic adaptations in an invasive copepod
Evolutionary origins of genomic adaptations in an invasive copepod
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DOI：
10.1038/s41559-020-1201-y
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发表时间：
2020-06-22
影响因子：
16.8
通讯作者：
Lee, Carol Eunmi
中科院分区：
文献类型：
--
作者：
Ben Stern, David;Lee, Carol Eunmi
种群扩大其地理范围的能力，无论是作为入侵者、农业品系还是气候移民，都是目前最严重的全球问题之一。然而，对于使某些种群（如生物入侵者）能够迅速过渡到新栖息地的因素，基本机制仍然知之甚少。根据一种假设，原生地的环境波动可以通过对关键性状施加平衡选择并维持使其能够快速适应新栖息地的遗传变异来促进成功的入侵。在这里，我们测试的基因组预测这一假设进行全基因组测序的多个独立的入侵淡水和原生盐水人口的桡足类Eurytemora affiniscomplex。我们发现，入侵种群通过平行使用相同的单核苷酸多态性和基因组位点，在比预期更大的程度上重复响应选择。这些相同的基因座在天然范围内富集了长期平衡选择的特征，其中15-47%的基因座表现出显著的平衡选择特征。入侵区的平行进化与原生区的平衡选择之间的强关联支持了这样一种假设，即波动的生境可以促进入侵的成功，平衡选择可能是一种广泛而重要的机制，使自然界能够快速适应。对多个独立入侵的桡足类淡水和原生盐水种群的基因组测序揭示了平衡选择与入侵之间的正关联。入侵种群的原生分布区和平行定向选择。
The ability of populations to expand their geographical ranges, whether as invaders, agricultural strains or climate migrants, is currently one of the most serious global problems. However, fundamental mechanisms remain poorly understood regarding factors that enable certain populations, such as biological invaders, to rapidly transition to novel habitats. According to one hypothesis, environmental fluctuations in the native range could promote successful invasions by imposing balancing selection on key traits and maintaining the genetic variation that enables rapid adaptation in novel habitats. Here we test the genomic predictions of this hypothesis by performing whole-genome sequencing of multiple independent invasive freshwater and native saline populations of the copepodEurytemora affiniscomplex. We found that invasive populations have repeatedly responded to selection through the parallel use of the same single-nucleotide polymorphisms and genomic loci, to a much greater degree than expected. These same loci were enriched for signatures of long-term balancing selection in the native ranges, with 15-47% of loci exhibiting significant signatures of balancing selection. The strong association between parallel evolution in the invaded range and balancing selection in the native range supports the hypothesis that fluctuating habitats can promote invasive success and that balancing selection might serve as a widespread and important mechanism that enables rapid adaptation in nature.Genome sequencing of multiple independent invading freshwater and native saline populations of a copepod reveals a positive association between balancing selection in the native range and parallel directional selection in the invading populations.