PECASE: Chemical Communication in Marine Ecosystems: Interactions Involving Harmful Algae and Zooplankton

提案题目：PECASE：海洋生态系统中的化学通信：涉及有害藻类和浮游动物的相互作用机构：佐治亚理工学院-佐治亚理工学院大多数生物使用化学信号来评估其环境并与其他生物进行通信。我们知道，用于防御、吸引配偶、选择栖息地和追踪食物的化学信号是至关重要的、广泛的和多样的。随着我们对受体-配体相互作用、生物合成途径、感觉生物学、流体动力学和生态系统功能的理解在过去十年中得到了极大的改善，解决海洋生物过程的化学问题的机会比以往任何时候都更有希望。该项目将重点研究海洋系统中化学通讯的生态效应，要求生物学和化学的显著结合，需要青年科学家积极参与假设的建立和检验，并训练学生的研究方法和通讯。在这项研究中，佛罗里达赤潮鞭毛藻短Karenia brevis （= Gymnodinium breve）将被用作一个模型系统，以了解浮游植物天然产物如何直接介导捕食等关键相互作用，从而影响种群和群落结构。浮游植物的化学反应也可能引起影响多个生态系统的食物网级联反应，并因藻华的远距离迁移而被放大。间接证据表明，一些有害藻类利用天然毒素来阻止浮游动物、贝类和以浮游生物为食的鱼类吃草，或者作为化感剂来对抗竞争的微藻，这可能有助于水华的增殖。这项研究将验证一种假设，即短凯伦氏菌产生的化合物可以保护它免受共生的桡足动物阿卡蒂亚·托萨的放牧。以桡足动物行为和生理摄食试验为指导的化学分馏将用于从短叶参提取物中分离出抗摄食化合物。生态活性化合物将通过波谱技术如核磁共振波谱和质谱（包括LC-MS）来鉴定。该研究将为研究食物网和单细胞生物与其敌人之间的竞争关系提供适应性方法，有效地将化学因素与形态和营养因素解耦。参与跨学科科学的学生需要培养强大的沟通能力，以跨越领域，在不牺牲科学严谨性和专业深度的情况下获得广泛的经验。为此目的，设计了两种新的教育机会。首先，计划为研究生和高年级本科生、研究人员和教师举办一个新的系列研讨会，讨论研究、政策和与非科学家交流的交叉点，以有害的藻华为例，作为公众感兴趣的科学例子。第二，将为研究生和本科生开设一门新的跨学科课程，讲授如何发现在水生生物中起线索作用的新型生物活性分子。该项目最初是作为职业奖资助的，并于2004年5月转换为工程师和科学家的总统早期职业奖（PECASE）奖。

Proposal Title: PECASE: Chemical communication in marine ecosystems: Interactions involving harmful algae and zooplanktonInstitution: Georgia Tech Research Corporation - GA Institute of TechnologyMost organisms use chemical signals to assess their environment and to communicate with other organisms. Chemical cues for the purposes of defense, mate attraction, habitat selection, and food tracking are known to be crucial, widespread, and diverse. As our understanding of receptor-ligand interactions, biosynthetic pathways, sensory biology, hydrodynamics, and ecosystem function has improved dramatically in the last decade, the opportunity to address the chemistry of marine biological processes has become more promising than ever before. This project will focus on the ecological effects of chemical communication in marine systems, demanding significant integration of biology and chemistry, involving active participation of young scientists in hypothesis building and testing, and training students in research methods and communication.In this study, the Florida red tide dinoflagellate Karenia brevis (= Gymnodinium breve) will be used as a model system for understanding how phytoplankton natural products directly mediate critical interactions such as predation, which affects population and community structure. Phytoplankton chemistry may also induce food-web cascades affecting multiple ecosystems, amplified by the movement of blooms over vast distances. Indirect evidence suggests that some harmful algae use natural toxins to deter grazing by zooplankters, shellfish, and planktivorous fish, or as allelopathic agents against competing microalgae, perhaps contributing to bloom proliferation. This study will test the hypothesis that chemical compounds produced by Karenia brevis defend it against grazing by the co-occurring copepod Acartia tonsa. Chemical fractionation guided by copepod behavioral and physiological feeding assays will be used to isolate antifeedant compounds from K. brevis extracts. Ecologically active compounds will be identified by spectroscopic techniques such NMR spectroscopy and mass spectrometry (including LC-MS). This research will provide adaptable methods for studying food-web and competitive relationships between unicellular organisms and their enemies, effectively decoupling chemical from morphological and nutritional factors. Students involved in interdisciplinary science need to develop strong communication skills for bridging fields and to acquire a breadth of experience without sacrificing scientific rigor and depth in their specialty. Towards these ends, two new educational opportunities have been designed. First, a new seminar series is planned for graduate and upper-undergraduate students, researchers, and faculty on the intersection of research, policy, and communication with non-scientists, using harmful algal blooms as an example of science that holds public interest. Second, a new interdisciplinary course will be developed for graduate and upper-undergraduate students on methodologies for the discovery of novel bioactive molecules that function as cues among aquatic organisms.This project was originally funded as a CAREER award, and was converted to a Presidential Early Career Award for Engineers and Scientists (PECASE) award in May 2004.