Let the right ones in: Testing microeconomic models of screening in an ant-bacteria microbiome

让合适的人进来：测试抗菌微生物组筛选的微观经济模型

• 批准号: NE/J01074X/1
• 负责人: Matthew Hutchings
• 金额: $ 54.45万
• 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: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FJ01074X%2F1
• 关键词: Let; right; ones; Testing; microeconomic

A group of ants in tropical America, known as the 'attines' or 'leafcutters,' evolved agriculture at least 50 million years ago. These ants collect plants and take them back to their nests, where they chew up the plants to feed a special fungus that is only able to live with leafcutter ants. Not surprisingly, in some parts of the New World, leafcutter ants are a pest, able to strip leaves off whole orange trees in one night, to feed enormous fungal gardens that fill underground ant nests as big as a two-story house (in London, not Las Vegas). 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 also protect their valuable fungal garden by weeding out moulds, which, if not controlled, would eventually consume the garden. The ants also apply antibiotics to kill the foreign moulds. They get the antibiotics from another mutualist, which also lives with the ants. These other mutualists are a special set of bacteria, called the actinomycetes, which are famous (amongst biologists) for making many kinds of antibiotics, some of which we use as medicine, like erythromycin. The actinomycetes are therefore also mutualists with the ant and the garden, because the bacteria fight disease, and in return, live on the ant bodies, where specialised glands appear to feed the bacteria.We have shown that many actinomycete species 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, are thought to have been handed down over generations, adapting to its ant hosts. Other actinomycetes, mostly in the group called Streptomyces, appear to be acquired anew from the soil in each generation. 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, and not harmful or useless bacteria. At a conceptual level, this problem is the same as the one faced by auto rescue companies wanting to sell coverage only to customers who own reliable cars. The characteristics of the soil bacteria and of potential customers are hidden, but everyone, good or bad, reliable or unreliable, wants to live on the ant or be rescued on the road.Economics has developed a solution to this problem of hidden characteristics, which is known as screening. Applied to ants, our hypothesis is that the ants provide the right mix of resources to promote fighting amongst bacteria. The winners are the ones that can release antibiotics, since the real purpose of antibiotics is to allow the producers to kill other bacteria. It happens that antibiotic-producing bacteria also have genes that make them resistant to their own antibiotics (and, because bacteria exchange genes, to many others), otherwise, they would commit suicide when they make antibiotics. The fighting produces a microbiome dominated by antibiotic-producing and -resistant bacteria, which, of course, is the desired outcome. One of our goals is to understand the mix of resources that promote the 'right kind of fighting' amongst bacteria. It appears now that every animal and every plant has a microbiome that provides important benefits, such as synthesising essential nutrients and defending against disease. An emerging idea in human medicine is that managing our own microbiome could cure some of our more recalcitrant diseases. The attine microbiome is just one of many, but its advantage is that we can do experiments with it, which gives us hope that we can work out general principles governing how to create and manage microbiomes.

生活在热带美洲的一群蚂蚁，被称为“attines”或“切叶蚁”，至少在 5000 万年前就进化出了农业。这些蚂蚁收集植物并将它们带回巢穴，在那里它们咀嚼植物来喂养一种只能与切叶蚁一起生活的特殊真菌。毫不奇怪，在新世界的某些地区，切叶蚁是一种害虫，它们能够在一夜之间把整棵橘子树上的叶子剥掉，为巨大的真菌花园提供食物，这些真菌花园充满了地下蚁巢，有两层楼那么大（在伦敦） ，不是拉斯维加斯）。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。蚂蚁还通过清除霉菌来保护它们宝贵的真菌花园，如果不加以控制，霉菌最终会吞噬花园。蚂蚁还会使用抗生素来杀死外来霉菌。它们从另一种共生生物那里获得抗生素，这种共生生物也与蚂蚁生活在一起。这些其他共生者是一组特殊的细菌，称为放线菌，它们因制造多种抗生素而闻名（在生物学家中），其中一些我们用作药物，例如红霉素。因此，放线菌与蚂蚁和花园也是互利共生的，因为细菌对抗疾病，作为回报，它们生活在蚂蚁身上，而蚂蚁身上有专门的腺体似乎为细菌提供食物。我们已经证明，许多放线菌物种生活在蚂蚁身上，并且提供抗生素混合物，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被认为是代代相传的，以适应其蚂蚁宿主。其他放线菌，主要属​​于链霉菌属，似乎每一代都是从土壤中重新获得的。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吸收有用的、产生抗生素的细菌，而不是有害或无用的细菌。从概念层面来看，这个问题与汽车救援公司所面临的问题相同，这些公司只想向拥有可靠汽车的客户出售保险。土壤细菌和潜在客户的特征是隐藏的，但每个人，无论好坏，可靠还是不可靠，都想靠蚂蚁为生，或者在路上被拯救。经济学已经为这个隐藏特征的问题找到了解决方案，即称为筛选。应用于蚂蚁，我们的假设是蚂蚁提供了正确的资源组合来促进细菌之间的战斗。胜利者是那些能够释放抗生素的人，因为抗生素的真正目的是让生产者杀死其他细菌。碰巧，产生抗生素的细菌也具有使它们对自己的抗生素产生抗药性的基因（而且，因为细菌与许多其他细菌交换基因），否则，它们在制造抗生素时就会自杀。战斗产生了以产生抗生素和耐药细菌为主的微生物组，这当然是期望的结果。我们的目标之一是了解促进细菌之间“正确战斗”的资源组合。现在看来，每一种动物和每一种植物都有一个微生物组，可以提供重要的益处，例如合成必需营养素和防御疾病。人类医学中的一个新兴想法是，管理我们自己的微生物组可以治愈一些更顽固的疾病。阿汀微生物组只是众多微生物组之一，但它的优势在于我们可以用它进行实验，这让我们希望能够制定出管理如何创建和管理微生物组的一般原则。

项目成果

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

Complete genome sequence of Streptomyces formicae KY5, the formicamycin producer.

福米霉素生产者福米卡链霉菌 KY5 的完整基因组序列。

• DOI: http://dx.10.1016/j.jbiotec.2017.11.011
• 发表时间: 2018
• 期刊: Journal of biotechnology
• 影响因子: 4.1
• 作者: Holmes NA

The regulation and biosynthesis of antimycins.

抗霉素的调控和生物合成。

• DOI: http://dx.10.3762/bjoc.9.290
• 发表时间: 2013
• 期刊: Beilstein journal of organic chemistry
• 作者: Seipke RF

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

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