Evolution of organismal composition and architecture in self-assembling fungal symbioses

自组装真菌共生中生物体组成和结构的进化

• 批准号: RGPIN-2019-04892
• 负责人: Spribille, Toby
• 金额: $ 2.77万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744833
• 关键词: Evolution; organismal; composition; architecture; self

Most forms of multicellular, multi-domain symbiosis recognized today involve large, structurally defining hosts dependent on microbial partners. Some symbioses, by contrast, possess body plans that are only achieved with all-microscopic symbionts. This is the case with lichens, symbiotic architectures based on interplay between a fungal and a photosynthesizing partner, usually single-celled algae or cyanobacteria. The partners are the microscopic equivalent of string (fungal hyphae) and balls (unicellular algae), and unable to form lichens on their own. The macroscopic architecture is effected by the gluing together of partner cells by extracellular polymers in specific motifs, essentially 3D biofilms. However, the cells along the "string" have interconnected cytoplasms and the "balls" are ostensibly autonomous. How they form a macroscopic lichen with conserved patterns and dimensions is unknown. My research uses modern tools to stress-test some of the most basic assumptions of lichen biology, assumptions that have been essentially unchallenged for 150 years. Application of shotgun DNA-, RNA- and protein sequencing has revealed that the core organismal assemblage found in a single lichen is invariably more than the twosome presented in textbooks. Additional fungi as well as bacteria appear to be constant components. However, identifying the functions of the previously overlooked microbes in turn requires revisiting our basic understanding of the lichen body plan and the glue that holds it together. My DG is dedicated to three main goal areas that aim to significantly close these knowledge gaps: How do core symbionts change across lichen architectures? I will use metagenomics to map changes in core symbionts over the evolution of an architecturally diverse group of lichens. I will compare individual genomes to understand how gene families changed along with the lichen in which the symbiont occurs. Finally, I will use confocal laser microscopy to visualize the symbionts in situ. What is the extracellular matrix that holds lichen symbionts in place? I will investigate extracellular polymer composition using specific staining approaches used in study biofilms, as well as targeted sampling of the matrix proteome and glycome. Which core symbionts contribute to this forming this layer? I will leverage our knowledge of biosynthetic pathways for lichen secondary metabolites to visualize which players are engaged in incorporating isotope-labeled precursors and producing these metabolites. Together with my parallel goal areas, this will be a powerful method of directly tying genomes to the goods and services pool of the total symbiont assemblage. The methods and approaches I am developing are at directly relevant to understanding complex eukaryote-prokaryote biofilm systems. My focus on cracking the give and take in this complex system will provide inroads for understanding other symbiotic systems that interact in biofilm-like contexts.

当今认识到的大多数形式的多细胞多域共生，涉及大型，结构上定义依赖微生物伴侣的宿主。相比之下，有些共生的身体计划只能通过全晶状体共生体来实现。地衣，共生体系结构是这种情况，基于真菌和光合作用伴侣（通常是单细胞藻类或蓝细菌）之间的相互作用。伴侣是弦乐（真菌菌丝）和球（单细胞藻类）的显微镜，无法自行形成地衣。宏观结构是由特定基序中的细胞外聚合物（基本上是3D生物膜）粘合在一起的。但是，沿着“弦”的细胞具有相互关联的细胞肿瘤，“球”表面上是自主的。它们如何形成具有保守模式和尺寸的宏观地衣是未知的。我的研究使用现代工具来强调地衣生物学的一些最基本的假设，这些假设本质上是没有挑战的150年。 shot弹枪DNA，RNA和蛋白质测序的应用表明，在单个地衣中发现的核心组合物总是比教科书中提出的两个sosemem均多。其他真菌和细菌似乎是恒定的成分。但是，确定先前被忽视的微生物的功能又需要重新审视我们对地衣身体计划和将其粘合在一起的胶水的基本理解。我的DG专门针对三个主要目标领域，旨在显着缩小这些知识差距：核心共生体如何在地衣体系结构中发生变化？我将使用宏基因组学来绘制核心共生体的变化，而构建多样的地衣群体的演变。我将比较单个基因组，以了解基因家族与共生体发生的地衣的变化。最后，我将使用共聚焦激光显微镜原位可视化共生体。什么是将地衣共生的细胞外基质？我将使用研究生物膜中使用的特定染色方法以及基质蛋白质组和糖的靶向采样研究细胞外聚合物组成。哪个核心共生体有助于这一层？我将利用我们对地衣次级代谢产物生物合成途径的知识来可视化哪些玩家参与合并同位素标记的前体并产生这些代谢物。与我的平行目标区域一起，这将是将基因组直接与共生组合总组合的商品和服务库直接绑定的强大方法。我正在开发的方法和方法与理解复杂的真核生物 - 概要生物膜系统直接相关。我对破解这个复杂系统的付出和采取的重点将为理解在类似生物膜的环境中相互作用的其他共生系统提供侵入。