Collaborative Research: RUI: Evaluating the Molecular Genetic Pathways Responsible for Stable Host: Symbiont Interactions in Sponge:Algal Associations

动物宿主和藻类共生体之间的细胞内关联支持着珊瑚礁等重要的生态系统。尽管这些关联很重要，但对宿主和藻类伙伴之间如何实现稳定相互作用的基本方面的了解有限。 这限制了我们就脆弱生态系统的管理做出明智决策的能力。例如，珊瑚礁会经历周期性的白化事件，涉及共生关系的崩溃并危及珊瑚礁的健康，但人们对白化过程和宿主随后的恢复知之甚少。为了保护我们宝贵的珊瑚礁资源，需要更好地了解共生伙伴之间的细胞和遗传相互作用。该项目将阐明在宿主：共生体交换中重要的保守基因调控途径的关键组成部分。随着海洋环境发生变化（例如，平均海水温度升高），必须充分了解宿主如何在细胞和遗传水平上支持共生体种群的细节。该项目计划产生一系列更广泛的影响，包括培训 STEM 本科生、参与大学前暑期桥梁计划以增加 STEM 的多样性、与国家领导人合作将本科生研究纳入社区学院，以及基于社区的高影响力学习机会。该研究将通过识别主效应共生基因和遗传途径来加深对宿主：共生体相互作用的理解。拟议的工作利用海洋和淡水海绵宿主及其藻类伙伴的独特特性来识别发生的分子、遗传、细胞和生理相互作用。这些特性允许控制共生体感染的时间，以便基因表达谱可以与共生体接触、吞噬、识别、细胞内迁移和重新增殖相关的事件相关联。该研究将以一种方法上新颖的方式创建宿主和藻类伙伴的不同组合，以探索为什么特定宿主成为特定共生体的合适栖息地而其他宿主无法支持这些共生体的原因。该项目将探索下调基因表达如何改变宿主：共生体相互作用的动态，并结合现场实验、RNAseq以及先进的生理、微观和分子工具，该研究将确定这些相互作用的共同调控特征。结果将增加对共生体栖息地要求以及宿主与不同伙伴互动的能力的了解。研究结果还将有助于确定共生伙伴身份的变化范围。除了以出版物和演示形式提供智力贡献外，该项目还将扩大大学预科生、社区学院和本科生的教育和研究机会，特别是那些来自贫困家庭的学生。该提案将支持本科课程背景下的高影响力实践，例如基于课程的研究和基于社区的学习，以及通过多学科教师学习社区和公民参与的讲座进行社区外展。

Intracellular associations between animal hosts and algal symbionts support important ecosystems like coral reefs. Despite the importance of these associations, there is limited understanding of basic aspects about how stable interactions between host and algal partners is achieved. This inhibits our ability to make informed decisions about the management of vulnerable ecosystems. For example, coral reefs experience periodic bleaching events that involve the breakdown of the symbiosis and jeopardize reef health, but the process of bleaching and subsequent recovery of the host are poorly understood. To protect our valuable reef resources, greater understanding of the cellular and genetic cross-talk between symbiotic partners is required. This project will elucidate key components of the conserved genetic regulatory pathways important in host:symbiont exchanges. As changes to ocean environments occur (e.g., increasing average seawater temperatures), it is imperative that details about how hosts support symbiont populations at the cellular and genetic level are fully understood. The project has a diverse suite of planned broader impacts including training of STEM undergraduates, involvement in a pre-college summer bridge program to increase diversity in STEM, partnerships with national leaders in incorporating undergraduate research in community colleges, and high impact community based learning opportunities.The research will refine understanding of host:symbiont interactions through identification of major-effect symbiosis genes and genetic pathways. The proposed work takes advantage of unique properties of marine and freshwater sponge hosts and their algal partners to identify the molecular, genetic, cellular, and physiological interactions that occur. These properties allow control over the timing of symbiont infection, so that gene expression profiles can be correlated with events involved with symbiont contact, engulfment, recognition, intracellular migration, and repopulation. In a methodologically novel way, the research will create different combinations of hosts and algal partners to explore reasons why particular hosts become suitable habitat for particular symbionts while other hosts cannot support those symbionts. The project will explore how down-regulating gene expression can change dynamics of host:symbiont interactions, and combining field-based experiments, RNAseq, and advanced physiological, microscopic, and molecular tools, the research will identify common regulatory features of those interactions. The results will increase understanding of the habitat requirements of the symbiont, and the ability of the hosts to interact with different partners. The results will also help define the scope of change in the identity of symbiotic partners. In addition to intellectual contributions in the form of publications and presentations, this project will expand educational and research opportunities for pre-college, community college, and undergraduate students, particularly those from underserved backgrounds. The proposal will support high impact practices like course-based research and community-based learning in the context of an undergraduate curriculum, as well as community outreach through a multi-disciplinary faculty learning community and civic-engaged talks.