Data from: Biogeographic barriers drive co-diversification within associated eukaryotes of the Sarracenia alata pitcher plant system

Understanding if the members of an ecological community have co-diversified is a central concern of evolutionary biology, as co-diversification suggests prolonged association and possible coevolution. By sampling associated species from an ecosystem, researchers can better understand how abiotic and biotic factors influence diversification in a region. In particular, studies of co-distributed species that interact ecologically can allow us to disentangle the effect of how historical processes have helped shape community level structure and interactions. Here we investigate the Sarracenia alata pitcher plant system, an ecological community where many species from disparate taxonomic groups live inside the fluid-filled pitcher leaves. Direct sequencing of the eukaryotes present in the pitcher plant fluid enables us to better understand how a host plant can shape and contribute to the genetic structure of its associated inquilines, and to ask whether genetic variation in the taxa are structured in a similar manner to the host plant. We used 454 amplicon-based metagenomics to demonstrate that the pattern of genetic diversity in many, but not all, of the eukaryotic community is similar to that of S. alata, providing evidence that associated eukaryotes share an evolutionary history with the host pitcher plant. Our work provides further evidence that a host plant can influence the evolution of its associated commensals.

解析生态群落内各物种是否发生共分化（co-diversification），是进化生物学的核心议题之一，因为共分化意味着类群间存在长期的共生关联，且可能伴随协同进化（coevolution）过程。通过对生态系统中的关联物种进行采样，研究者能够更深入地解析非生物因子（abiotic factors）与生物因子（biotic factors）如何影响区域内的物种分化进程。尤为关键的是，针对生态位相互作用且同域分布的物种开展研究，可帮助我们厘清历史演化过程如何塑造群落级结构与物种间互作关系。本研究聚焦于黄花瓶子草（Sarracenia alata）捕虫囊生态系统——这一生态群落中，诸多隶属于不同分类类群的物种栖息于充满液体的捕虫叶内腔中。对捕虫囊液体中的真核生物进行直接测序，有助于我们深入解析宿主植物如何塑造并调控其伴生内栖类群（inquilines）的遗传结构，同时可探究这些类群的遗传变异结构是否与宿主植物呈现相似的分布模式。本研究采用基于454测序平台的扩增子宏基因组学（amplicon-based metagenomics）技术，证实了该生态群落中多数（而非全部）真核类群的遗传多样性模式与黄花瓶子草高度相似，为伴生真核生物与宿主瓶子草共享演化历史提供了直接证据。本研究进一步证实，宿主植物可对其伴生共生物（commensals）的演化进程产生显著影响。