Host‐associated bacterial community succession during amphibian development
Host‐associated bacterial community succession during amphibian development
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DOI：
10.1111/mec.14507
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发表时间：
2018-04
影响因子：
4.9
通讯作者：
T. Prest;Abigail K. Kimball;Jordan G. Kueneman;V. McKenzie
中科院分区：
文献类型：
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作者：
T. Prest;Abigail K. Kimball;Jordan G. Kueneman;V. McKenzie
两栖动物在其生命周期中经历了重大的发育变化，因为它们通常从主要是水生环境迁移到更多的陆地环境。两栖动物皮肤是一种粘膜组织，它聚集了共生微生物群的群落。然而，关于两栖动物在哪里获得皮肤共生体，以及微生物共生体的来源是否在整个发育过程中发生变化，目前还不是很清楚。在这项研究中，我们利用了从四个野生北方蟾蜍种群(Anaxyus Boreas)收集的数据；具体地说，我们采集了蟾蜍发育过程中的皮肤细菌群落，包括卵、蝌蚪、亚成虫和成体以及环境细菌的来源(水、水沉积物和土壤)。利用16S rRNA标记基因图谱和SourceTracker相结合的方法，我们发现在整个生命周期中，初级环境来源保持不变，而北方蟾蜍共生体的次要来源随着发育而发生显著变化。我们发现，蟾蜍皮肤群落在发育过程中发生了可预测的变化，并且两种发育障碍事件(卵孵化和变态)决定了主要的变化。在每一种发育障碍之后，蟾蜍皮肤群落聚集到另一种稳定状态。使用预测的每个生命阶段群落的平均rRNA操纵子拷贝数，我们展示了皮肤细菌群落如何经历一种演替模式，即“快速生长”(共养)通用细菌首先占主导地位，然后“慢生长”(寡养)专门细菌占据主导地位。我们的研究强调了与宿主相关的细菌群落组装如何与宿主发育紧密耦合，以及与宿主相关的群落表现出的演替模式类似于在自由生活的细菌以及大型动物群落中观察到的模式。
Amphibians undergo significant developmental changes during their life cycle, as they typically move from a primarily aquatic environment to a more terrestrial one. Amphibian skin is a mucosal tissue that assembles communities of symbiotic microbiota. However, it is currently not well understood as to where amphibians acquire their skin symbionts, and whether the sources of microbial symbionts change throughout development. In this study, we utilized data collected from four wild boreal toad populations (Anaxyrus boreas); specifically, we sampled the skin bacterial communities during toad development, including eggs, tadpoles, subadults and adults as well as environmental sources of bacteria (water, aquatic sediment and soil). Using 16S rRNA marker gene profiling coupled with SourceTracker, we show that while primary environmental sources remained constant throughout the life cycle, secondary sources of boreal toad symbionts significantly changed with development. We found that toad skin communities changed predictably across development and that two developmental disturbance events (egg hatching and metamorphosis) dictated major changes. Toad skin communities assembled to alternative stable states following each of these developmental disturbances. Using the predicted average rRNA operon copy number of the communities at each life stage, we showed how the skin bacterial communities undergo a successional pattern whereby “fast‐growing” (copiotroph) generalist bacteria dominate first before “slow‐growing” (oligotroph) specialized bacteria take over. Our study highlights how host‐associated bacterial community assembly is tightly coupled to host development and that host‐associated communities demonstrate successional patterns akin to those observed in free‐living bacteria as well as macrofaunal communities.