Collaborative Research: Ontogenic change in Cnidarian-algal symbioses: A genomic and ecologic perspective

珊瑚(Cnidaria：Hex orallia：Sholactinia)和光合甲藻共生体(Alveolata：Dinophycea：Symbioddium)之间的共生为珊瑚礁生态系统的基础和结构提供了基础和结构，并对全球碳和生物地球化学循环作出了重大贡献。鉴于这种共生对珊瑚-藻类和珊瑚礁生态系统的重要性，了解管理这种共生的建立和长期维持的机制是至关重要的。该项目的总体目标是确定导致成虫寄主藏匿的共生体最终聚集的机制和选择性过程。这个问题将从生态和基因组两个角度来探讨，具体目的是确定(1)不同的共生菌菌株是否在成年珊瑚进入成熟的共生体时对珊瑚的适合性产生不同的影响；(2)共生体之间的竞争或环境条件是否有助于最终的宿主-共生体配对；(3)随着宿主内的共生体群落的筛选，宿主/共生体的转录本如何变化到在成年宿主中发现的最终组合。直接影响珊瑚适合性的特征(即生长、存活、能量产生)将在不同环境条件下对实验上感染不同类型共生线虫的珊瑚新兵的个体发育进行测量。同时，将使用高通量基因表达谱来跟踪宿主和共生体之间基因表达的变化。总之，这些数据将被用来验证或证伪在成年宿主中发现的最终共生菌组合取决于(A)宿主选择(B)共生菌之间的竞争和/或(C)环境条件的假设。这项研究汇集了两个实验室的专业知识，这两个实验室专注于共生的这些方面。Coffroth实验室开创了共生和共生生物多样性早期个体发育研究的先河，并将继续在生态学研究中处于领先地位。麦地那实验室在开发和利用基因组技术研究共生建立和破坏期间转录变化方面走在了前列。此外，麦地那实验室拥有将在这项研究中使用的珊瑚微阵列，并将在2009年根据454个EST数据获得两种共生生物的寡核苷酸阵列。虽然有几个小组对寄主转录组进行了初步研究，但没有一个小组在单一实验中结合了检查寄主和共生体的方法。这将是一种强有力的方法，因为它将使研究人员能够追踪寄主和共生体之间基因表达的互补变化，并将这些变化与共生体群落中的更替联系起来。这项研究产生的数据将弥合我们对珊瑚-共生体共生的建立和维持的理解上的一个重要差距。了解(S)调节共生建立的机制将拓宽我们的知识，并有助于预测这种共生对未来气候条件的反应。与过去一样，基因组工具(阵列、EST)将通过阵列成本分配、微阵列分析培训或序列数据随时提供给研究人员，为继续探索这些系统提供宝贵的资源。科夫罗斯将与尼亚加拉水族馆一起开发教育和推广计划，向当地教师和普通公众培训和传播有关珊瑚礁的信息。麦地那实验室将继续与加州大学默塞德分校的本科生一起制作多种语言(英语、西班牙语和苗语)的科学和环境播客，并将继续与加州科学院(CAS)合作推广珊瑚礁。此外，这项工作将对一名博士后研究员、至少一名研究生和至少两名本科生进行培训和指导。通过这个项目，这些学生将有机会在实验室和野外环境中参与研究，学习一系列生态、分子和藻类养殖技术。布法罗大学收藏的大量培养物是全世界研究人员可以获得的重要资源，拟议的资金将有助于维持这一资源。我们的科技成果注解通过我们的科技数据库(http://sequoia.ucmerced.edu/SymBioSys/).)公开提供

PROJECT SUMMARYThe symbiosis between corals (Cnidaria:Hexacorallia:Scleractinia) and photosynthetic dinoflagellate symbionts (Alveolata: Dinophycea: Symbiodinium) provides the foundation and structure of the coral reef ecosystem, as well as significant contributions to global carbon and biogeochemical cycles. Given the importance of this symbiosis to the coral-algal holobiont and the reef ecosystem, understanding the mechanisms governing the establishment and long term maintenance of this symbiosis is essential. The overall aim of this project is to identify the mechanisms and selective processes that lead to thefinal assemblage of symbionts harbored by adult hosts. This question will be approached from two perspectives, ecologic and genomic, with the specific aims of determining (1) if different Symbiodinium strains differentially affect fitness of corals as the adult settles into a mature symbiosis (2) if competition among symbionts or environmental conditions contribute to the final host-symbiont pairing and (3) how host/symbiont transcriptomes varying as the symbiont community within a host is winnowed to the final assemblage found in the adult host. Traits that directly affect coral fitness (i.e. growth, survivorship, energy production) will be measured under different environmental conditions over the ontogeny of coral recruits that are experimentally infected with different types of Symbiodinium. Concurrently, high throughput gene expression profiling will be used to follow changes in gene expression between host and symbiont. Together, these data will be used to validate or falsify the hypotheses that the final symbiont assemblage found in the adult host is determined by (a) host selection (b) competition among symbionts and/or (c) environmental condition.This study pools the expertise of two labs that have focused on these aspects of the symbiosis. The Coffroth lab pioneered the studies on early ontogeny of the symbiosis and symbiont diversity and will continue to take the lead in the ecological studies. The Medina lab is at the forefront in the development and utilization of genomic technology to study transcriptomic changes during the establishment and breakdown of the symbiosis. Furthermore, the Medina lab has the coral microarrays to be used in this study and in 2009 will also have oligo arrays for two Symbiodinium species based on 454 EST data. Although several groups have initial studies of the host transcriptome, none have combined an approach that examines the host and the symbiont in a single experiment. This will be a powerful approach as it will allow the investigators to track complementary changes in gene expression between host and symbiont and relate those to turnover in the symbiont community as the final symbiont complement is established.The data resulting form the study will bridge an important gap in our understanding of the establishment and maintenance of coral-Symbiodinium symbiosis. Understanding the mechanism(s) regulating the establishment of the symbiosis will broaden our knowledge and help to predict the response of this symbiosis to future climate conditions. As in the past, the genomic tools (arrays, ESTs) will be made readily available to researchers via array distribution at cost, microarray analysis training, or sequence data, providing valuable resources to continue exploring these systems.In conjunction the Aquarium of Niagara, Coffroth will develop educational and outreach programs to train and disseminate information on coral reefs to local area teachers and the general public. The Medina lab will continue to produce science and environment podcasts in multiple languages (English, Spanish and Hmong) with undergraduate students at UC Merced and will continue to collaborate with the California Academy of Sciences (CAS) in their coral reef outreach efforts. Additionally, this work will result in the training and mentoring of a postdoctoral fellow, at least one graduate student and at least 2 undergraduates. Through this project these students will have the opportunity to participate in research in both a lab and field setting, learning a range of ecological, molecular and algal culturing techniques. The extensive culture collection housed at the University at Buffalo is an important resource that is available to researchers worldwide which the proposed funding will help to maintain. Our EST annotations are publicly available through our EST database (http://sequoia.ucmerced.edu/SymBioSys/).