Genomic diversity of a nectar yeast clusters into metabolically, but not geographically, distinct lineages
Genomic diversity of a nectar yeast clusters into metabolically, but not geographically, distinct lineages
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DOI：
10.1111/mec.14535
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发表时间：
2018-04-01
影响因子：
4.9
通讯作者：
Fukami, Tadashi
中科院分区：
文献类型：
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作者：
Dhami, Manpreet K.;Hartwig, Thomas;Fukami, Tadashi
扩散限制和环境分类都会影响种群的遗传变异，但它们的贡献仍不清楚，特别是在微生物中。我们试图确定地理距离（作为扩散限制的代表）和表型性状（作为环境分选的代表），包括形态、代谢能力和种间竞争力，对花蜜酵母物种 Metschnikowia reukaufii 的基因型多样性的贡献。为了测量基因型多样性，我们对从加州 200 公里海岸线沿线的蜂鸟授粉灌木 Mimulus aurantiacus 的花蜜中分离出的 102 个 M. reukaufii 菌株的基因组进行了测序。种内遗传变异与地理距离没有可检测的关系，但可以分为与代谢能力和种间竞争力相关的三个不同的谱系。尽管有充足的证据表明花蜜酵母内部和之间存在强烈的竞争性相互作用，但在 200 公里的海岸线上观察到的全谱基因型和表型多样性甚至在小至 200 m 的尺度上也得到了体现。此外，更具竞争力的菌株并不一定更丰富。这些结果表明，扩散限制和环境分类可能无法完全解释这种微生物的种内多样性，并强调还需要考虑其他生态因素，例如权衡、源库动态和生态位修改。
Both dispersal limitation and environmental sorting can affect genetic variation in populations, but their contribution remains unclear, particularly in microbes. We sought to determine the contribution of geographic distance (as a proxy for dispersal limitation) and phenotypic traits (as a proxy for environmental sorting), including morphology, metabolic ability and interspecific competitiveness, to the genotypic diversity in a nectar yeast species, Metschnikowia reukaufii. To measure genotypic diversity, we sequenced the genomes of 102 strains of M. reukaufii isolated from the floral nectar of hummingbird-pollinated shrub, Mimulus aurantiacus, along a 200-km coastline in California. Intraspecific genetic variation showed no detectable relationship with geographic distance, but could be grouped into three distinct lineages that correlated with metabolic ability and interspecific competitiveness. Despite ample evidence for strong competitive interactions within and among nectar yeasts, a full spectrum of the genotypic and phenotypic diversity observed across the 200-km coastline was represented even at a scale as small as 200 m. Further, more competitive strains were not necessarily more abundant. These results suggest that dispersal limitation and environmental sorting might not fully explain intraspecific diversity in this microbe and highlight the need to also consider other ecological factors such as trade-offs, source-sink dynamics and niche modification.