Dimensions: Collaborative Research: Processes that Generate and Maintain Phylogenetic, Genetic, and Functional Diversity of the Freshwater Mussel Holobiont across Multiple Scales

术语“全息生物”是指宿主和与其相关的微生物（“微生物组”）之间相互作用的总和。然而，宿主和微生物群落中不同生物组织水平的多样性对生态系统内功能多样性的影响程度表明，我们对全球生物多样性的理解存在相当大的差距。该项目将成为了解河流生态系统中产生和维持生物多样性的一个里程碑。淡水贻贝是一种高度濒危的物种丰富的动物，它们通过滤食和营养循环在河流中发挥着关键作用。尽管淡水贻贝的生态价值得到了广泛的认可，但人们对单个物种的遗传多样性、贻贝群落的物种组成和多样性，以及贻贝群落与肠道微生物群之间的相互作用等因素如何跨环境和地理尺度构建这些生态过程知之甚少。同样，人们对宿主-微生物群的相互作用是如何随着时间的推移构建这两个群体的进化知之甚少。如果能够确定这些动物生物多样性模式的过程和机制，管理人员将更好地为保护和恢复工作做出明智的决定，最终将有利于整个生态系统。该项目采用从个体到种群到物种及以上水平的方法，旨在了解当代分类群和祖先谱系中宿主和微生物组系统发育过程中环境、遗传多样性、功能性状和群落组装之间的生态和进化联系。本研究将整合分析(1)一组淡水贻贝物种种内遗传多样性，(2)贻贝物种群落及其相关微生物组的系统发育多样性，以及(3)贻贝-微生物组整体生物的功能多样性。整合生物多样性的这三个维度将使我们能够理解支撑淡水贻贝在生态系统中扮演的角色的机制，并理解构成空间和时间上生物多样性的基本生态和进化过程。此外，这项工作将广泛地为公共数据库提供关于物种分布、丰度、微生境环境特征和DNA序列变化的新数据，这些数据将对基础的进化和生态学研究产生影响，同时也为高度濒危和生态重要群体的保护和管理提供信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The term 'holobiont' is used to refer to an organism as the sum of the interactions between the host and the microbes associated with them (the 'microbiome'). Yet, the extent to which diversity at different levels of biological organization in host and microbiome communities influence functional diversity within ecosystems represents a considerable gap in our understanding of global biodiversity. This project will represent a landmark in understanding what generates and maintains biodiversity in river ecosystems. Freshwater mussels are a highly imperiled, species-rich group of animals that play critical roles in rivers through their filter-feeding and cycling of nutrients. Although the ecological value of freshwater mussels is widely appreciated, little is known about how factors like genetic diversity of individual species, species composition and diversity of mussel communities, or interactions between mussel communities and their gut microbiomes structure these ecological processes across environments and geographic scales. Similarly, little is known about how host-microbiome interactions have structured the evolution of both groups over time. If the processes and mechanisms underlying patterns of biodiversity in these animals can be identified, managers will be better armed to make informed decisions for conservation and restoration efforts that will ultimately benefit the entire ecosystem. Using approaches that scale from individual-to-population-to-species levels and above, this project seeks to understand ecological and evolutionary associations among the environment, genetic diversity, functional traits, and community assembly across both host and microbiome phylogenies in contemporary taxa and ancestral lineages. This research will integrate analyses of (1) intraspecific genetic diversity in a suite of freshwater mussel species, (2) phylogenetic diversity of communities of mussel species as well as their associated microbiomes, and (3) functional diversity of the mussel-microbiome holobiont. Integrating these three dimensions of biodiversity will allow us to comprehend the mechanisms that underpin the roles that freshwater mussels play in ecosystems, and to understand the fundamental ecological and evolutionary processes that structure biodiversity in space and over time. Furthermore, this work will extensively populate public databases with new data on species distributions, abundances, microhabitat environmental characteristics, and DNA sequence variation that will have impacts on basic evolutionary and ecology research while also informing conservation and management of a highly imperiled and ecologically important group.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.