CAREER: Assessing local adaptation in the chemosynthetic symbionts of hydrothermal vent animals

深海温泉，被称为热液喷口，是由动物主导的，它们必须依靠细菌共生体在食物有限的深海中获得营养。这些动物在它们的组织中或组织上培养细菌，这些细菌利用排出液体中的化学能作为能量来制造糖，这个过程被称为化学合成。虽然它们需要共生体来生存，但大多数共生喷口动物在其发育的某个阶段从环境池中获得共生体。特别是对于长期分散的海洋动物，很可能会遇到新的栖息地条件时，他们解决，长期以来一直假设，收购当地最佳的共生菌株解决后可能具有生态和进化优势。为了验证这一想法，PI将评估与西太平洋深海热液喷口的一种基础蜗牛属Alviniconcha相关的细菌共生体的当地适应性。该项目将利用种群基因组学方法和高压生理实验，评估栖息地特异性共生体菌株对不同栖息地条件的适应是否存在差异。该项目调查了关于深海喷口适应的基本假设，并为我们了解Alviniconcha的生态提供了关键信息，Alviniconcha是一种重要的基础物种，由于迫在眉睫的深海采矿活动，已被自然保护联盟红色名录评为“濒危”或“脆弱”。除了支持本科生和研究生参与研究外，该项目还包括创建一个开放的，专家撰写和同行评审的深海生物学数字教科书，该教科书整合了深海媒体，为公众使用提供了重要资源，以及培训PI作为一种资源，并倡导开放教育资源。尽管它对了解热液中优势动物群的生态学具有重要意义，在喷口生态系统中，化学合成共生体的当地适应问题仍然没有得到很好的解决。该项目将利用种群基因组学和类似普通花园的实验，评估与西太平洋深海热液喷口的一个基螺属Alviniconcha相关的细菌共生体的当地适应情况。首先，将对Alviniconcha进行高分辨率地球化学调查，并结合共生体种群基因组学，以调查当地适应的基因组证据。这将有助于确定可能在适应当地地球化学方面发挥作用的基因座。第二，高压，普通花园般的实验将进行直接评估当地适应的潜力，并调查与观察到的表型相关的共生体基因组特征。最后，将对西太平洋Alviniconcha共生体种群进行种群基因组学研究，以确定在多个地理尺度、宿主种群连通性水平和生境差异强度上可能对当地共生体适应性做出贡献的基因组特征。该奖项反映了NSF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。

Deep-sea hot springs, called hydrothermal vents, are dominated by animals that obligately rely on bacterial symbionts for nutrition in the otherwise food-limited deep-sea. These animals farm bacteria in or on their tissues that use the chemical energy in venting fluid as energy to make sugar, in a process known as chemosynthesis. Though they require their symbionts for survival, most symbiotic vent animals acquire their symbionts from an environmental pool at some point in their development. Especially for long-dispersing marine animals that are likely to encounter new habitat conditions when they settle, it has long been hypothesized that acquisition of a locally optimal symbiont strain after settlement may have ecological and evolutionary advantages. To test this idea, the PI will evaluate local adaptation in the bacterial symbionts associated with a foundation snail genus, Alviniconcha, at deep-sea hydrothermal vents in the western Pacific. Using population genomics methods and high-pressure physiological experiments, this project will assess whether habitat-specific symbiont strains differ in their adaptation to different habitat conditions. The project investigates a fundamental hypothesis regarding adaptation at deep-sea vents, as well as provides key information in our understanding of the ecology of Alviniconcha, a genus of important foundation species that has been assessed as “Endangered” or “Vulnerable” on the IUCN Red List due to looming deep-sea mining activity. In addition to supporting undergraduates and graduate students to participate in research, this project includes the creation of an open, expert-authored and peer-reviewed Deep-Sea Biology digital textbook that integrates deep-sea media, providing a vital resource for public use, as well as training the PI as a resource and advocate for open educational resources.Despite its significance for understanding the ecology of the dominant fauna at hydrothermal vent ecosystems, local adaptation in chemosynthetic symbionts is still poorly addressed. This project will use population genomics and common-garden-like experiments to assess local adaptation in the bacterial symbionts associated with a foundation snail genus, Alviniconcha, at deep-sea hydrothermal vents in the western Pacific. First, high-resolution geochemical surveys of Alviniconcha will be coupled with symbiont population genomics to investigate genomic evidence for local adaptation. This will allow for the identification of loci that may play a role in adaptation to local geochemistry. Second, high-pressure, common-garden-like experiments will be performed to directly assess the potential for local adaptation and investigate underlying symbiont genomic traits associated with observed phenotypes. Finally, Alviniconcha symbiont populations across the western Pacific will be characterized with population genomics to identify the genomic traits potentially contributing to local symbiont adaptation across multiple geographical scales, levels of host population connectivity, and intensities of site-to-site habitat differences.This project is jointly funded by the Biological Oceanography Program, the Established Program to Stimulate Competitive Research (EPSCoR), the Evolutionary Processes Program, and the Ocean Education Program.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.