BACKGROUND The eco-evolutionary processes ruling post-disturbance microbial assembly remain poorly studied, particularly in host-microbiome systems. The community recovery depends not only on the type, duration, intensity, and gradient of disturbance, but also on the initial community structure, phylogenetic composition, legacy, and habitat (soil, water, host). In this study, yellow perch (Perca flavescens) juveniles were exposed over 90 days to constant and gradual sublethal doses of cadmium chloride. Afterward, the exposure of aquaria tank system to cadmium was ceased for 60 days. The skin, gut and water tank microbiomes in control and treatment groups, were characterized before, during and after the cadmium exposure using 16s rDNA libraries and high throughput sequencing technology (Illumina, Miseq). RESULTS Our data exhibited long-term bioaccumulation of cadmium salts in the liver even after two months since ceasing the exposure. The gradient of cadmium disturbance had differential effects on the perch microbiota recovery, including increases in evenness, taxonomic composition shifts, as well as functional and phylogenetic divergence. The perch microbiome reached an alternative stable state in the skin and nearly complete recovery trajectories in the gut communities. The recovery of skin communities showed a significant proliferation of opportunistic fish pathogens (i.e., Flavobacterium). Our findings provide evidence that neutral processes were a much more significant contributor to microbial community turnover in control treatments than in those treated with cadmium, suggesting the role of selective processes in driving community recovery. CONCLUSIONS The short-term metallic disturbance of fish development has important long-term implications for host health. The recovery of microbial communities after metallic exposure depends on the magnitude of exposure (constant, gradual), and the nature of the ecological niche (water, skin, and gut). The skin and gut microbiota of fish exposed to constant concentrations of cadmium (CC) were closer to the control negative than those exposed to the gradual concentrations (CV). Overall, our results show that the microbial assembly during the community recovery were both orchestrated by neutral and deterministic processes. Video Abtract.

中文翻译：

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逐渐和持续的金属扰动后，黄色鲈鱼微生物组的群落恢复动态。

背景技术关于扰动后微生物组装的生态进化过程仍然缺乏研究，特别是在宿主微生物组系统中。群落恢复不仅取决于扰动的类型，持续时间，强度和梯度，还取决于初始群落结构，系统发育组成，遗产和栖息地（土壤，水，宿主）。在这项研究中，黄色鲈鱼（Perca flavescens）的幼虫在90天内暴露于恒定和渐进亚致死剂量的氯化镉中。此后，停止将水族箱系统暴露于镉中60天。使用16s rDNA文库和高通量测序技术（Illumina，Miseq）对对照组和治疗组中的皮肤，肠道和水箱微生物组进行了特征分析，包括镉暴露之前，期间和之后。结果我们的数据显示，即使停止暴露后两个月，肝脏中镉盐的长期生物蓄积也是如此。镉干扰的梯度对鲈鱼微生物群的恢复具有不同的影响，包括均匀度的增加，生物分类组成的变化以及功能和系统发育的差异。高位微生物群在皮肤中达到了一种替代的稳定状态，在肠道群落中达到了几乎完整的恢复轨迹。皮肤群落的恢复表明机会鱼病原体（即黄杆菌）大量繁殖。我们的发现提供了证据，表明中性过程在控制处理中比微生物处理对微生物群落更新的影响更大，表明选择性过程在推动社区恢复中的作用。结论鱼类发育的短期金属干扰对寄主健康具有重要的长期影响。金属暴露后微生物群落的恢复取决于暴露的程度（恒定，渐进）和生态位的性质（水，皮肤和肠道）。暴露于恒定浓度的镉（CC）的鱼的皮肤和肠道菌群比暴露于逐渐浓度（CV）的鱼类的皮肤和肠道菌群更接近于对照阴性。总体而言，我们的结果表明，社区恢复过程中的微生物组装都是由中性和确定性过程精心策划的。视频摘要。金属暴露后微生物群落的恢复取决于暴露的程度（恒定，渐进）和生态位的性质（水，皮肤和肠道）。暴露于恒定浓度的镉（CC）的鱼的皮肤和肠道菌群比暴露于逐渐浓度（CV）的鱼类的皮肤和肠道菌群更接近对照阴性。总体而言，我们的结果表明，社区恢复过程中的微生物组装都是由中性和确定性过程精心策划的。视频摘要。金属暴露后微生物群落的恢复取决于暴露的程度（恒定，渐进）和生态位的性质（水，皮肤和肠道）。暴露于恒定浓度的镉（CC）的鱼的皮肤和肠道菌群比暴露于逐渐浓度（CV）的鱼类的皮肤和肠道菌群更接近于对照阴性。总体而言，我们的结果表明，社区恢复过程中的微生物组装都是由中性和确定性过程精心策划的。视频摘要。我们的结果表明，社区恢复过程中的微生物组装都是由中性和确定性过程精心安排的。视频摘要。我们的结果表明，社区恢复过程中的微生物组装都是由中性和确定性过程精心安排的。视频摘要。