宿主相关微生物群落,像其他生态社区一样,可能会通过优先效应受到分类群定殖顺序的影响。发育中的胚胎及其相关的微生物在细菌定殖期间受到随机性的影响。对于两栖动物胚胎,通常在细菌丰富的环境中外部发育,这种随机性可能特别有影响。例如,两栖动物微生物组可以减轻疾病对其宿主的致命后果;然而,这可能取决于微生物组的组成。这里,我们检查了春季窥视器(Pseudacriscrusifer)胚胎和t中细菌群落的组装。首先,我们在实验室或野外环境中从确定的交配对中饲养胚胎,以检查环境和亲子关系对胚胎和t细菌群落的相对影响。第二,我们通过实验接种胚胎,以确定优先效应(i)是否可用于增加Janthinobacteriumlividum的相对丰度,一种能够预防真菌感染的两栖动物相关细菌,和(ii)将导致观察到的来自假单胞菌属的两种密切相关的细菌的相对丰度的差异。使用16SrRNA基因扩增子测序,我们观察到基于胚胎和t的饲养位置和亲子关系的群落组成差异。在接种实验中,我们发现,优先接种可以增加鱼腥草的相对丰度,但是没有发现,当给予优先权时,任何一种假单胞菌分离株都能够防止另一种的定植。这些结果突出了环境源库和亲子关系在确定微生物组组成方面的重要性。同时还提供了用于施用已知的两栖动物益生菌的新方法。
目的:利用宿主相关细菌的功能是管理不同宿主物种疾病结局的一种有前景的机制。在两栖动物的情况下,某些与青蛙相关的细菌可以减轻真菌病原体Batrachochytriumdendrobatidis感染的致死性结果。成功的益生菌应用需要了解群落组装的知识以及对构建这些共生细菌群落的生态机制的理解。在我们的研究中,我们显示了环境和亲子关系在确定细菌群落组成方面的重要性,并且群落组成可以受到优先效应的影响。Further,我们为使用细菌优先效应作为增加发育中宿主中目标益生菌分类群相对丰度的机制提供了支持。虽然我们的结果表明,优先效应并非对所有宿主相关细菌都普遍有效,我们增加特定益生菌类群的相对丰度的能力可能会增强依赖于濒危脊椎动物圈养的保护策略。
Host-associated microbial communities, like other ecological communities, may be impacted by the colonization order of taxa through priority effects. Developing embryos and their associated microbiomes are subject to stochasticity during colonization by bacteria. For amphibian embryos, often developing externally in bacteria-rich environments, this stochasticity may be particularly impactful. For example, the amphibian microbiome can mitigate lethal outcomes from disease for their hosts; however, this may depend on microbiome composition. Here, we examined the assembly of the bacterial community in spring peeper (Pseudacris crucifer) embryos and tadpoles. First, we reared embryos from identified mating pairs in either lab or field environments to examine the relative impact of environment and parentage on embryo and tadpole bacterial communities. Second, we experimentally inoculated embryos to determine if priority effects (i) could be used to increase the relative abundance of Janthinobacterium lividum, an amphibian-associated bacteria capable of preventing fungal infection, and (ii) would lead to observed differences in the relative abundances of two closely related bacteria from the genus Pseudomonas. Using 16S rRNA gene amplicon sequencing, we observed differences in community composition based on rearing location and parentage in embryos and tadpoles. In the inoculation experiment, we found that priority inoculation could increase the relative abundance of J. lividum, but did not find that either Pseudomonas isolate was able to prevent colonization by the other when given priority. These results highlight the importance of environmental source pools and parentage in determining microbiome composition, while also providing novel methods for the administration of a known amphibian probiotic.
OBJECTIVE: Harnessing the functions of host-associated bacteria is a promising mechanism for managing disease outcomes across different host species. In the case of amphibians, certain frog-associated bacteria can mitigate lethal outcomes of infection by the fungal pathogen Batrachochytrium dendrobatidis. Successful probiotic applications require knowledge of community assembly and an understanding of the ecological mechanisms that structure these symbiotic bacterial communities. In our study, we show the importance of environment and parentage in determining bacterial community composition and that community composition can be influenced by priority effects. Further, we provide support for the use of bacterial priority effects as a mechanism to increase the relative abundance of target probiotic taxa in a developing host. While our results show that priority effects are not universally effective across all host-associated bacteria, our ability to increase the relative abundance of specific probiotic taxa may enhance conservation strategies that rely on captive rearing of endangered vertebrates.