Gut Microbiota as a Trigger of Accelerated Directional Adaptive Evolution: Acquisition of Herbivory in the Context of Extracellular Vesicles, MicroRNAs and Inter-Kingdom Crosstalk.
Gut Microbiota as a Trigger of Accelerated Directional Adaptive Evolution: Acquisition of Herbivory in the Context of Extracellular Vesicles, MicroRNAs and Inter-Kingdom Crosstalk.
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DOI：
10.3389/fmicb.2017.00721
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发表时间：
2017
影响因子：
5.2
通讯作者：
Romano M
中科院分区：
文献类型：
--
作者：
Romano M
根据传统观点，脊椎动物的特定饮食是构成肠道微生物区系的关键因素之一。在这种解释中，微生物区系处于从属地位，较大的宿主通过进化及其适合性形成宿主微生物区系的分类组成。目前的贡献表明，在Holobion这一新概念的框架内，食草动物的进化、跨王国串扰的可能性及其表观遗传效应如何可以为完全相反的解释铺平道路：微生物区系可以塑造和塑造一般的宿主结构，以增加其适应性，而不是被动地塑造。在这种情况下，需要考虑的核心因素是跨王国串扰、通过粪便中的纳米囊将RNA从父母传递给后代的可能性，以及表观遗传过程的激活，这些过程垂直地代代相传。新的假设是，肠道微生物区系可能在草食性脊椎动物的宏观进化动力学中发挥重要作用，直接通过表观遗传性质的宿主-微生物区系对话(即甲基化、组蛋白乙酰化等)，导致生物表型的重大变化。同样的微生物群落从父母到后代的垂直交换，这些具有相当一致基因型别的微生物之间的相互作用，以及发生这些过程的社会限制群体，都可以解释为什么食草动物在脊椎动物的进化过程中多次(且独立地)出现。新的解释也可能代表着一个关键因素，可以理解在非常遥远的谱系中相似的身体结构的趋同进化。
According to a traditional view, the specific diet in vertebrates is one of the key factors structuring the composition of the gut microbiota. In this interpretation, the microbiota assumes a subordinate position, where the larger host shapes, through evolution and its fitness, the taxonomical composition of the hosted microbiota. The present contribution shows how the evolution of herbivory, framed within the new concept of holobiont, the possibility of inter-kingdom crosstalk and its epigenetic effects, could pave the way to a completely reversed interpretation: instead of being passively shaped, the microbiota can mold and shape the general host body structure to increase its fitness. Central elements to consider in this context are the inter-kingdom crosstalk, the possibility of transporting RNAs through nanovesicles in feces from parents to offspring, and the activation of epigenetic processes passed on vertically from generation to generation. The new hypothesis is that the gut microbiota could play a great role in the macroevolutionary dynamics of herbivorous vertebrates, causing directly through host-microbiota dialog of epigenetic nature (i.e., methylation, histone acetylation, etc.), major changes in the organisms phenotype. The vertical exchange of the same microbial communities from parents to offspring, the interaction of these microbes with fairly uniform genotypes, and the socially restricted groups where these processes take place, could all explain the reasons why herbivory has appeared several time (and independently) during the evolution of vertebrates. The new interpretation could also represent a key factor in understanding the convergent evolution of analogous body structures in very distant lineages.