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.

热带美洲的一群蚂蚁，被称为Attines，在5000-6000万年前进化出了农业。这些蚂蚁收集植物材料，并将其带回巢中，在那里它们将其咀嚼，并将其喂给一种只能生活在蚂蚁巢中的特殊真菌。进化程度最高的鸟类被称为切叶者，因为它们会主动从雨林树冠上的高处砍下树叶，然后把它们带回家，作为真菌的食物。作为住房和食物的回报，这种真菌产生了富含脂肪和糖的结构，被称为贡利迪亚，蚂蚁收获这些结构作为食物。科学家将这种相互依赖称为互惠互利，因为蚂蚁和真菌是互惠互利的。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，这些微生物最终会吞噬花园。蚂蚁还会使用抗生素来杀死外来微生物。他们从另一个互助者那里获得抗生素，这是一组特殊的丝状细菌，称为放线菌，它们以制造多种抗生素而闻名(在生物学家中)。放线菌是蚂蚁和真菌花园的互惠共生者，因为细菌抗击疾病，作为回报，细菌生活在蚂蚁身上，那里专门的腺体似乎喂养细菌。通过之前的NERC资助，我们已经证明了不同的放线菌细菌生活在蚂蚁身上，并提供了一种抗生素的混合物，可能是为了减缓入侵真菌花园的疾病中抗生素耐药性的进化。生物学家将寄主生物体上的细菌群落称为微生物群。在这种微生物群中，有一组放线菌，称为假球虫，已经代代相传(垂直传播)，并适应了它们的蚂蚁宿主。其他放线菌，大多数属于链霉菌，似乎是在每一代中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，但不知何故，蚂蚁能够有选择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伴侣选择？我们已经证明，要入侵一只覆盖着假单胞菌的蚂蚁，另一种细菌菌株必须制造抗生素，这样它才能在一段时间内与假单胞菌作战，而且它还必须对假单胞菌制造的抗生素具有抗药性，这样它才不会被杀死。我们称之为筛查，结果是产生了一个由产生抗生素和耐药细菌主导的微生物群，当然，这是蚂蚁想要的结果，因为它可以使用抗生素的混合物。在这个新项目中，我们想要在更深的层面上了解这一系统，分解假单胞菌互助者，以了解它们产生的抗生素及其如何影响‘伴侣选择’，并测试蚂蚁是否真的为细菌提供食物，这是假单胞菌的私人食物还是公共食物，即所有细菌都可以使用。我们还计划进行实验，以找出这些切叶蚂蚁的角质层上到底存在哪些细菌，以及它们在每只蚂蚁身上的确切位置。通过这种方式，我们将建立第一个动物宿主的3D微生物组地图，并在其上覆盖最大量生产的抗生素的地图。使用蚂蚁对这些微生物群进行研究和建模的好处是，它们很容易保存，而且它们的微生物群在外面，这意味着我们可以用它做实验。这给了我们希望，我们可以制定出一般原则，管理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群。

项目成果

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

• DOI: 10.3389/fmicb.2016.02073
• 发表时间: 2016
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Holmes NA;Innocent TM;Heine D;Bassam MA;Worsley SF;Trottmann F;Patrick EH;Yu DW;Murrell JC;Schiøtt M;Wilkinson B;Boomsma JJ;Hutchings MI
• 通讯作者: Hutchings MI

Chemical warfare between fungus-growing ants and their pathogens.

• DOI: 10.1016/j.cbpa.2020.08.001
• 发表时间: 2020-12
• 期刊: Current opinion in chemical biology
• 影响因子: 7.8
• 作者: Batey SFD;Greco C;Hutchings MI;Wilkinson B
• 通讯作者: Wilkinson B

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

• DOI: 10.1039/c6sc04265a
• 发表时间: 2017-04-01
• 期刊: Chemical science
• 影响因子: 8.4
• 作者: Qin Z;Munnoch JT;Devine R;Holmes NA;Seipke RF;Wilkinson KA;Wilkinson B;Hutchings MI
• 通讯作者: Hutchings MI

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

• DOI: 10.1099/mic.0.000524
• 发表时间: 2017-10
• 期刊: Microbiology (Reading, England)
• 作者: Som NF;Heine D;Holmes N;Knowles F;Chandra G;Seipke RF;Hoskisson PA;Wilkinson B;Hutchings MI
• 通讯作者: Hutchings MI

The Conserved Actinobacterial Two-Component System MtrAB Coordinates Chloramphenicol Production with Sporulation in Streptomyces venezuelae NRRL B-65442.

• DOI: 10.3389/fmicb.2017.01145
• 发表时间: 2017
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Som NF;Heine D;Holmes NA;Munnoch JT;Chandra G;Seipke RF;Hoskisson PA;Wilkinson B;Hutchings MI
• 通讯作者: Hutchings MI