Partner choice: How does a host select and control its microbiome?

合作伙伴选择：宿主如何选择和控制其微生物组？

• 批准号: NE/M015033/1
• 负责人: Matthew Hutchings
• 金额: $ 58.01万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FM015033%2F1
• 关键词: Partner; choice; How; does; host

A group of ants in tropical America, known as the attines, evolved agriculture 50-60 million years ago. These ants collect plant material and take it back to their nests, where they chew it up and feed it to a special fungus that is only able to live in attine ant nests. The most highly evolved attines are known as leafcutters because they actively cut leaves from high up in the rainforest canopy and carry them back as food for their fungus. In return for housing and food, the fungus produces fat- and sugar-rich structures, called gongylidia that the ants harvest as food. Scientists call this co-dependence a mutualism because the ants and the fungus mutually benefit each other. The ants protect their valuable fungal gardens by weeding out unwanted microbes (fungi and bacteria), which, if not controlled, would eventually consume the garden. The ants also apply antibiotics to kill the foreign microbes. They get the antibiotics from another mutualist, a special set of filamentous bacteria, called actinomycetes, which are famous (amongst biologists) for making many kinds of antibiotics. The actinomycetes are mutualists with the ant and the fungus garden, because the bacteria fight disease, and in return, live on the ant bodies, where specialised glands appear to feed the bacteria.With previous NERC funding we have shown that different actinomycete bacteria live on the ants and provide a mixture of antibiotics, probably to slow down the evolution of antibiotic resistance in the diseases that invade the fungus gardens. Biologists call the bacterial communities that live on a host organism its microbiome. In the attine microbiome, one group of actinomycetes, known as Pseudonocardia, have been handed down over generations (vertically transmitted), and have adapted to their ant hosts. Other actinomycetes, mostly in a group called Streptomyces, appear to be acquired anew from the soil in each generation (horizontal transmission). This is surprising, because the soil is full of bacteria, most of which are not Streptomyces, but somehow the ant is able to selectively take up useful, antibiotic-producing bacteria from their environment, and not harmful or useless bacteria. How does the ant make the right Partner Choice? We have shown that to invade an ant covered in Pseudonocardia another bacterial strain must make antibiotics so it can fight the Pseudonocardia for some space and it must also be resistant to antibiotics made by the Pseudonocardia so it doesn't get killed. We call this SCREENING and it results in a microbiome dominated by antibiotic-producing and -resistant bacteria, which, of course, is the desired outcome for the ant because it gets a mixture of antibiotics to use. In this new project we want to understand this system at an even deeper level, taking apart both the Pseudonocardia mutualists to understand the antibiotics they produce and how they influence 'Partner Choice' and to test whether the ants really do provide food to the bacteria and whether this is private to Pseudonocardia or public, that is, available to all bacteria. We also plan experiments to find out exactly which bacteria are present on these leafcutter ant cuticles and exactly where they are on individual ants. In this way we will build the first 3D microbiome maps of an animal host and overlay it with maps of the most abundantly produced antibiotics. The advantage of using attine ants to study and model these microbiomes is that they are easy to keep and their microbiome is on the outside, which means we can do experiments with it. This gives us hope that we can work out general principles governing how to create and manage protective microbiomes in free-living marine and terrestrial systems, including all land plants.

生活在热带美洲的一群蚂蚁，被称为“阿汀蚂蚁”，在 50-6000 万年前就进化出了农业。这些蚂蚁收集植物材料并将其带回巢穴，在那里它们将其咀嚼并将其喂给一种只能生活在蚂蚁巢穴中的特殊真菌。进化程度最高的阿汀被称为切叶者，因为它们主动从雨林树冠的高处切下叶子，并将它们带回来作为真菌的食物。作为住房和食物的回报，真菌会产生富含脂肪和糖的结构，称为“gongylidia”，蚂蚁将其收获作为食物。科学家将这种相互依赖称为互利共生，因为蚂蚁和真菌互惠互利。蚂蚁通过清除不需要的微生物（真菌和细菌）来保护它们宝贵的真菌花园，如果不加以控制，这些微生物最终将吞噬花园。蚂蚁还使用抗生素来杀死外来微生物。它们从另一种共生菌中获得抗生素，这是一种特殊的丝状细菌，称为放线菌，它们因制造多种抗生素而闻名（在生物学家中）。放线菌与蚂蚁和真菌花园是互利共生的，因为细菌可以对抗疾病，作为回报，它们生活在蚂蚁身上，蚂蚁身上有专门的腺体来喂养细菌。通过之前的 NERC 资助，我们已经证明不同的放线菌可以生活在蚂蚁身上。蚂蚁并提供抗生素混合物，可能是为了减缓入侵真菌花园的疾病的抗生素耐药性的演变。生物学家将寄主生物体上生活的细菌群落称为微生物组。在蚂蚁微生物组中，一组被称为假诺卡氏菌的放线菌已经世代相传（垂直传播），并且已经适应了它们的蚂蚁宿主。其他放线菌，主要属​​于链霉菌属，似乎在每一代中都是从土壤中重新获得的（水平传播）。这是令人惊讶的，因为土壤中充满了细菌，其中大多数不是链霉菌，但蚂蚁能够以某种方式选择性地从环境中吸收有用的、产生抗生素的细菌，而不是有害或无用的细菌。蚂蚁如何做出正确的合作伙伴选择？我们已经证明，要入侵一只被假诺卡氏菌覆盖的蚂蚁，另一种细菌菌株必须产生抗生素，这样它才能与假诺卡氏菌争夺一些空间，而且它还必须对假诺卡氏菌产生的抗生素有抵抗力，这样它就不会被杀死。我们称之为筛选，它会产生以产生抗生素和耐药细菌为主的微生物组，这当然是蚂蚁所期望的结果，因为它可以使用抗生素的混合物。在这个新项目中，我们希望更深入地了解这个系统，将假诺卡氏菌互利共生体拆开，了解它们产生的抗生素以及它们如何影响“伙伴选择”，并测试蚂蚁是否真的为细菌提供食物，无论这是假诺卡氏菌私有的还是公共的，即所有细菌都可以使用的。我们还计划进行实验，以找出这些切叶蚁角质层上到底存在哪些细菌，以及它们在单个蚂蚁身上的确切位置。通过这种方式，我们将构建第一个动物宿主的 3D 微生物组图，并将其与最丰富的抗生素图覆盖。使用蚂蚁来研究和建模这些微生物组的优点是它们很容易饲养，而且它们的微生物组在外面，这意味着我们可以用它来做实验。这让我们希望能够制定出一般原则，指导如何在自由生活的海洋和陆地系统（包括所有陆地植物）中创建和管理保护性微生物组。

项目成果

Chemical warfare between fungus-growing ants and their pathogens.

真菌生长的蚂蚁与其病原体之间的化学战。

• DOI: http://dx.10.1016/j.cbpa.2020.08.001
• 发表时间: 2020
• 期刊: Current opinion in chemical biology
• 影响因子: 7.8
• 作者: Batey SFD

ActinoBase: tools and protocols for researchers working on Streptomyces and other filamentous actinobacteria.

ActinoBase：为研究链霉菌和其他丝状放线菌的研究人员提供的工具和协议。

• DOI: http://dx.10.1099/mgen.0.000824
• 发表时间: 2022
• 期刊: Microbial genomics
• 影响因子: 3.9
• 作者: Feeney MA

Genome Analysis of Two Pseudonocardia Phylotypes Associated with Acromyrmex Leafcutter Ants Reveals Their Biosynthetic Potential.

与顶切叶蚁相关的两种假诺卡氏菌系统型的基因组分析揭示了它们的生物合成潜力。

• DOI: http://dx.10.3389/fmicb.2016.02073
• 发表时间: 2016
• 期刊: Frontiers in microbiology
• 作者: Holmes NA

The MtrAB two-component system controls antibiotic production in Streptomyces coelicolor A3(2).

MtrAB 双组分系统控制天蓝色链霉菌 A3(2) 中抗生素的产生。

• DOI: http://dx.10.1099/mic.0.000524
• 发表时间: 2017
• 期刊: Microbiology (Reading, England)
• 作者: Som NF

Formicamycins, antibacterial polyketides produced by Streptomyces formicae isolated from African Tetraponera plant-ants.

福米卡霉素，由从非洲 Tetraponera 植物蚂蚁中分离出来的福米卡链霉菌 (Streptomyces formicae) 产生的抗菌聚酮化合物。

• DOI: http://dx.10.1039/c6sc04265a
• 发表时间: 2017
• 期刊: Chemical science
• 影响因子: 8.4
• 作者: Qin Z