Molecular Probes for Nutrient Stress in Phytoplankton: Emiliania Huxleyi as a Model

Palenik 9818543浮游植物营养胁迫的分子探针：Emiliania huxleyi作为模式。存在许多例子，浮游植物的类型和生理状态影响海洋中的主要过程，如碳固定，钙化，硫气体排放和有毒水华形成。然而，我们理解单个浮游植物物种或单个细胞的生理状态的能力是有限的。目前，大多数生物学领域的测量（碳固定，C：N比，Fv/Fm，例如）集成在整个浮游植物群落。从长远来看，对单个“关键”浮游植物物种的生理生态学的理解将提供一个更机械的，预测性的理解生态系统processes.Emiliania huxleyi是一个丰富的，世界性的浮游植物物种，这是重要的全球碳和硫的地球化学循环，因为它的生产在水柱中的方解石（cocoliths）和硫气体DMS。它存在于贫营养和浅海环境中，已知在某些地方会形成卫星图像中可见的大规模水华。到目前为止，我们对这种生物生态学的理解主要集中在这些水华现象上。浮游植物生态学领域的研究目标之一是发展不依赖于培养的浮游植物营养状况探测器。从以前的工作，抗体的细胞表面蛋白，NRP 1，这是目前在氮应激，但不硝酸盐-充满或氨-充满E。赫胥黎被开发了。在这项研究中，抗体将用于开发一种表征天然E. huxleyi种群。将优化全细胞测定，并表征其效率和灵敏度，以检查低至贫营养环境中存在的细胞数量。荧光显微镜和图像分析将用于定量表达NRP 1的细胞数量，理想情况下是相对表达水平。将开发完整细胞的抗体，以计数样品中氮应激细胞的总数和百分比。一些以前从加州电流和挪威海岸获得的样品将进行初步测试，在该领域的氮应力细胞的存在。演示特定浮游植物群体的生理状态将是新颖的。这项工作将包括训练一名研究生和一名或多名本科生掌握将免疫学探针应用于海洋生态问题的新兴技术。

Palenik 9818543Molecular Probes for Nutrient Stress in Phytoplankton: Emiliania huxleyi as a model.Numerous examples exist where both the type and physiological status of the phytoplankton influence major processes in the oceans such as carbon fixation, calcification, sulfur gas emission, and toxic bloom formation. Our ability to understand the physiological status in the field of individual phytoplankton species or individual cells is limited, however. Most biological field measurements (carbon fixation, C:N ratio, Fv/Fm, for example) currently integrate over the whole phytoplankton community. In the long term, an understanding of the physiological ecology of individual "keystone" phytoplankton species will provide a more mechanistic, predictive understanding of ecosystem processes.Emiliania huxleyi is an abundant, cosmopolitan phytoplankton species which is important in the global biogeochemical cycles of carbon and sulfur because of its production in the water column of calcite (coccoliths) and the sulfur gas DMS. It is present in both oligotrophic and neritic environments and in some locations is known to form massive blooms visible in satellite images. To date our understanding of the ecology of this organism has focused on these bloom phenomena.One of the research goals of the field of phytoplankton ecology is the development of incubation-independent probes of phytoplankton nutrient status. From previous work an antibody to a cell surface protein, NRP1, that is present in nitrogen-stressed, but not nitrate--replete or ammonia-replete E. huxley has been developed. In this study the antibody will be used to develop a field method for characterizing the physiological state of natural E. huxleyi populations. A whole cell assay will be optimized and its efficiency and sensitivity characterized for examining cell numbers down to those present in oligotrophic environments. Fluorescence microscopy and image analysis will be used to quantify the number of cells expressing NRP1 and ideally the relative level of expression.An antibody to intact whole cells will be developed to count the total and percent nitrogen-stressed cells in samples. A few previously obtained samples from the California current and the coast of Norway will be tested initially for the presence of nitrogen-stressed cells in the field. The demonstration of the physiological state of a specific phytoplankton group would be novel. This work will involve the training of one graduate student and one or more undergraduates in emerging techniques for applying immunological probes to marine ecological questions.