En-Gen: Genome-Enabled Environmental Functional Genomics and Expression Profiling of Diatoms in the Ocean

硅藻贡献了高达25%的海洋总生产力，是世界上最大的渔业的基础。它们的基因组似乎经过了精细的调整，能够在现代世界的环境条件下取得成功。它们迅速生长，并将环境中的二氧化碳吸收到非常低的水平，并在获得硝酸盐和铁等基本营养物质时迅速做出反应。即使在不开花的条件下，它们也可以像小而丰富的蓝藻一样快速生长。然而，与蓝藻不同的是，直到现在才有可能从功能基因组学和比较基因组学来洞察它们的成功。这个项目将利用新获得的硅藻基因组来发现环境中的自然组合高度表达哪些基因，以便直接从生物体那里了解它们对不同环境条件做出反应的性质和时间框架。这个项目中的方法建立在这些研究人员之前的结果基础上，使用单基因研究和来自铁和氮胁迫条件下培养的基因序列的库中的数据。研究人员已经确定了一组候选基因来研究，这些基因涉及碳和氮代谢，以及对营养限制的压力反应。这些基因将被部署在诊断微阵列上，以发现在水华和营养限制条件下，哪些基因在天然海水中高度表达。这些方法将使研究人员能够确定硅藻功能基因组学研究的关键基因靶点，以调查海洋硅藻对环境因素的反应，包括温度升高和大气二氧化碳增加导致的pH值下降造成的变化，并预测对营养胁迫的生理反应和可能的群落反应。硅藻是现代世界中相对较新的生物，它们在与氧合光合作用时代初期截然不同的环境条件下进化。鉴于硅藻在现代世界中取得了巨大的生态成功，重要的是了解它们成功的遗传基础，从而了解它们对未来不断变化的条件可能做出的反应。研究人员、他们的博士后研究员和研究生将参加一个暑期项目，培训科学教师，并为他们提供课程支持，介绍硅藻在世界海洋中的重要性，以及研究这些浮游植物群落重要成员的现代基因组学方法。该项目还将通过从当地专科学校和调查人员所在机构招聘暑期实习生来支持和赞助本科生研究。

Diatoms contribute up to 25 % of total ocean productivity and are the basis of the world's greatest fisheries. Their genomes appear to be finely tuned to succeed under the environmental conditions of the modern world. They grow rapidly into blooms and draw down the ambient carbon dioxide to very low levels, and respond rapidly to essential nutrients such as nitrate and iron when they become available. Even in non-bloom conditions, they can grow as rapidly as the small and abundant cyanobacteria. Unlike the cyanobacteria, however, insights into their success from functional and comparative genomics have not been possible until now. This project will use newly available diatom genomes to discover which genes are highly expressed by natural assemblages in the environment in order to learn directly from the organisms about the nature and time frame of their response to different environmental conditions. The approach in this project builds on previous results from these investigators using single gene studies and data from libraries of gene sequences derived from cultures under conditions of iron and nitrogen stress. The investigators have identified a suite of candidate genes to study that are involved in carbon and nitrogen metabolism, and the stress response to nutrient limitation. These genes will be deployed on a diagnostic microarray to discover which genes are highly expressed in natural seawater under bloom and nutrient limiting conditions. These approaches will allow the investigators to identify critical gene targets for functional genomics research in diatoms in order to investigate the response of marine diatoms to environmental factors, including changes resulting from elevated temperatures and decreasing pH as a result of increasing atmospheric carbon dioxide, and to predict physiological and possibly community responses to nutrient stress. Diatoms are relative newcomers to the modern world, having evolved under dramatically different environmental conditions than those present at the beginning of the era of oxygenic photosynthesis. Given the great ecological success of diatoms in the modern world, it is important to understand the genetic basis of their success, and thus their possible responses to changing conditions in the future. The investigators, their postdoctoral fellows, and graduate students will participate in a summer program to train science teachers and provide them with curriculum support on the importance of diatoms in the worlds oceans and the modern genomic approaches to studying these important members of the phytoplankton community. The project will also support and sponsor undergraduate research by recruiting summer intern students from the local junior colleges as well as from the home institution of the investigators.