ANT LIA: Do Molecular Data Support High Endemism and Divergent Evolution of Antarctic Marine Nematodes and their Host-associated Microbiomes?

摘要：南大洋的长期隔离和独特的生物多样性是了解种群进化和生态的重要案例研究区域。本研究利用现代组学方法对南极海洋线虫及其宿主相关微生物群落的生物多样性、进化和生态学进行了研究。研究结果正在产生一个重要的南极动物多样性基线数据集。在这个项目中产生的所有基因组资源将作为开源数据集公开访问，具有长期科学重用的潜力。该项目支持来自代表性不足背景的不同研究人员，并制作了一套以南极为重点的数字公共宣传产品。技术摘要：线虫在世界范围内的海洋沉积物生境中数量丰富，普遍存在，在养分循环和沉积物稳定等方面发挥着重要作用。然而，对这一门的研究一直存在严重的分类缺陷，正式描述的海洋物种不到5000种。由于采样有限和南极底栖动物一般难以接近，南大洋的动物群研究得特别少。本研究首次对南极东部大陆架的海洋线虫进行了大规模的分子研究，为现有的历史（形态）分类研究提供了重要的比较数据集。该项目结合了经典分类学（显微镜）和现代组学工具，以实现三个总体目标：1)确定分子数据是否支持南极底栖生态系统中底栖动物的高生物多样性和地方性；2)确定了南极陆架上具有深海与浅水进化起源的海洋线虫物种比例，并评估了南大洋的隐物种形成模式；3)确定南极海洋线虫宿主相关微生物组的最重要驱动因素。该项目旨在快速推进对南极微型动物进化起源的认识，提供对关键指标属种群水平格局的见解，并阐明可能影响微生物组格局的潜在生态和环境因素。更广泛的影响活动包括一项密集的邮轮和陆地推广计划，重点关注社交媒体参与和数字推广产品，提高对南极海洋生态系统和未被充分研究的微生物-动物关系的认识。包括女科学家、第一代大学生、拉丁裔研修生在内的多元化研究团队。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。

Non-technical Abstract:The long isolation and unique biodiversity of the Southern Ocean represents an important case study region for understanding the evolution and ecology of populations. This study uses modern -omics approaches to evaluate the biodiversity, evolution, and ecology of Antarctic marine nematodes and their host-associated microbiomes from a variety of habitats collected at different depths. The results are producing an important baseline dataset of Antarctic meiofaunal diversity. All genomic resources generated in this project will be publicly accessible as open-source datasets with the potential for long-term scientific reuse. This project supports diverse researchers from underrepresented backgrounds and produces a suite of Antarctic-focused digital public outreach products.Technical Abstract:Nematode worms are abundant and ubiquitous in marine sediment habitats worldwide, performing key functions such as nutrient cycling and sediment stability. However, study of this phylum suffers from a perpetual and severe taxonomic deficit, with less than 5,000 formally described marine species. Fauna from the Southern Ocean are especially poorly studied due to limited sampling and the general inaccessibility of the Antarctic benthos. This study is providing the first large-scale molecular-based investigation from marine nematodes in the Eastern Antarctic continental shelf, providing an important comparative dataset for the existing body of historical (morphological) taxonomic studies. This project uses a combination of classical taxonomy (microscopy) and modern -omics tools to achieve three overarching aims: 1) determine if molecular data supports high biodiversity and endemism of benthic meiofauna in Antarctic benthic ecosystems; 2) determine the proportion of marine nematode species that have a deep-sea versus shallow-water evolutionary origin on the Antarctic shelf, and assess patterns of cryptic speciation in the Southern Ocean; and 3) determine the most important drivers of the host-associated microbiome in Antarctic marine nematodes. This project is designed to rapidly advance knowledge of the evolutionary origins of Antarctic meiofauna, provide insight on population-level patterns within key indicator genera, and elucidate the potential ecological and environmental factors which may influence microbiome patterns. Broader Impacts activities include an intensive cruise- and land-based outreach program focusing on social media engagement and digital outreach products, raising awareness of Antarctic marine ecosystems and understudied microbial-animal relationships. The diverse research team includes female scientists, first-generation college students, and Latinx trainees.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.