Dimensions: Collaborative Research: Processes that generate and maintain phylogenetic, genetic, and functional diversity of the freshwater mussel holobiont across multiple scales

术语“全生物体”用于指作为宿主和与它们相关的微生物（“微生物组”）之间相互作用的总和的生物体。然而，宿主和微生物群落中不同生物组织水平的多样性在多大程度上影响生态系统内的功能多样性，这在我们对全球生物多样性的理解中存在相当大的差距。该项目将成为理解河流生态系统中生物多样性产生和维持的一个里程碑。淡水贻贝是一种高度危险的，物种丰富的动物群体，通过它们的滤食和营养循环在河流中发挥着关键作用。虽然淡水贻贝的生态价值得到了广泛的认可，但人们对个体物种的遗传多样性，贻贝群落的物种组成和多样性，或贻贝群落与肠道微生物之间的相互作用等因素如何在环境和地理尺度上构建这些生态过程知之甚少。同样，关于宿主-微生物组相互作用如何随着时间的推移构建这两个群体的进化也知之甚少。如果能够确定这些动物生物多样性模式的过程和机制，管理人员将能够更好地为保护和恢复工作做出明智的决定，最终使整个生态系统受益。使用从个体到种群到物种水平及以上的方法，该项目旨在了解当代分类群和祖先谱系中宿主和微生物组的环境，遗传多样性，功能特征和社区组装之间的生态和进化关联。这项研究将整合分析（1）种内遗传多样性在一套淡水贻贝物种，（2）贻贝物种的群落系统发育多样性以及它们相关的微生物组，和（3）功能多样性的贻贝微生物组holobiont。整合生物多样性的这三个方面将使我们能够理解淡水贻贝在生态系统中发挥作用的机制，并了解在空间和时间上构建生物多样性的基本生态和进化过程。此外，这项工作将广泛填充公共数据库的新数据，物种分布，丰度，微生境环境特征，和DNA序列变异，这将对基本的进化和生态学研究产生影响，同时也为保护和管理一个高度危险和生态上重要的群体提供信息。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的学术价值和更广泛的影响评审标准。

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.