Nutritional, environmental, and genetic regulation of toxicity and growth in Dinophysis

甲藻属从生态、进化和公共卫生的角度来看是重要的。在前一类中，本属的一些成员通过一个独特的、多阶段的过程获得营养，需要隐藻和纤毛虫的猎物。在进化上，隐藻叶绿体在取食过程中的修饰及其随后的光合作用的利用为质体的获得和进化的研究提供了一个模型系统。从公共卫生的角度来看，甲藻物种是绝大多数贝类中毒（DSP）病例的原因。DSP是一种综合征，主要与食用积累了甲藻毒素的贝类有关。这是一个重大的健康和经济问题，对许多国家，是其中最重要的和广泛的有害藻华（HAB）相关的中毒综合征。几十年来，许多方面的甲藻生理，毒性和遗传学仍然是棘手的，由于我们无法在实验室培养和维护这些生物。然而，由于最近的一项突破，这一障碍不再存在，现在可以进行一系列重要的实验和测量。在多个方面取得重大进展的机会是巨大的。研究人员将进行一项全面的研究，以调查营养，环境和遗传调控的毒性和生长的甲藻。他们的总体假设是，甲藻毒素的变异性不仅受甲藻物种和菌株之间的遗传差异，而且还受纤毛虫和隐藻食物可用性和质量的差异以及环境影响的影响。他们将建立一个地理上多样化的文化收藏，包括各种分离的甲藻，多囊藻和其他纤毛虫，和隐藻的遗传特征。这些文化收藏品中的大部分已经在本次提交之前收集完毕。文化组合，然后将被用来调查甲藻和纤毛虫的摄食选择性，放牧率和增长。下一个主要目标是探索甲藻毒素变异的机制。这将包括分析地理上分散的甲藻分离物喂养的一系列纤毛虫和隐藻，以及环境因素，如温度，光照和营养物质在毒素生产中的作用的检查。该研究项目将依赖于一个经过验证的系统和方法-在PI实验室中以高速度生长了数月的Dinophysis培养物，建立的实验方案以及使用最先进仪器和技术的复杂毒素化学。该项目将开始回答甲藻生理学、生态学、毒性和进化方面的长期问题，同时提供有关重大公共卫生和经济问题的有价值信息。该项目适合本科生，研究生和博士后培训。PI安德森将支持博士生在这个项目上，并将在研究中涉及几个本科实习生以及。安德森通常支持几个东北大学实习生谁在实验室工作6个月，以获得经验，以指导教育和职业选择。博士后学者朱丽叶·史密斯将参加毒素分析，在WHOI奖学金。由此产生的培养物收集将与该领域的其他工作人员分享，以加速科学进步。项目成果将通过科学论文、在讲习班、会议和研讨会上的介绍以及与媒体的讨论广泛传播。此外，由于正在研究的生物体是影响世界各国的一种主要贝类中毒形式的原因，该项目具有重大的实际意义，可以满足促进发现与其服务社会之间联系的标准。

The dinoflagellate genus Dinophysis is important from ecological, evolutionary, and public health perspectives. In the former category, some members of this genus derive their nutrition through a unique, multi-stage process requiring cryptophyte and ciliate prey. Evolutionarily, the modification of cryptophyte chloroplasts during feeding and their subsequent utilization for photosynthesis provides a model system for investigations of plastid acquisition and evolution. From the public health perspective, Dinophysis species are responsible for the vast majority of diarrhetic shellfish poisoning (DSP) cases. DSP is a syndrome predominantly associated with consumption of shellfish that have accumulated Dinophysis toxins. It is a major health and economic problem for many countries and is among the most important and widespread of the harmful algal bloom (HAB)-associated poisoning syndromes.For decades, many aspects of Dinophysis physiology, toxicity, and genetics have remained intractable due to our inability to grow and maintain these organisms in laboratory cultures. As a result of a recent breakthrough, however, this obstacle no longer exists and an array of important experiments and measurements are now possible. The opportunities for major advances on multiple fronts are significant. The investigators will conduct a comprehensive study to investigate nutritional, environmental, and genetic regulation of toxicity and growth in Dinophysis. Their overall hypothesis is that toxin variability in Dinophysis is regulated not only by genetic differences among Dinophysis species and strains, but also by differences in ciliate and cryptophyte food availability and quality, and by environmental influences as well. They will establish and genetically characterize a geographically diverse culture collection that will include a variety of isolates of Dinophysis, Myrionecta and other ciliates, and cryptophytes. Much of this culture collection has already been assembled in advance of this submission. The culture assemblage will then be used to investigate Dinophysis and ciliate feeding selectivity, grazing rates, and growth. The next major objective is to explore mechanisms underlying toxin variability in Dinophysis. This will include analysis of geographically dispersed Dinophysis isolates fed with an array of ciliates and cryptophytes, as well as an examination of the role of environmental factors such as temperature, light, and nutrients in toxin production. The research project will rely on a proven system and methods - cultures of Dinophysis that have been growing at high rates in the PI's laboratory many months, established experimental protocols, and sophisticated toxin chemistry using state-of-the-art instruments and techniques. This project will begin to answer longstanding questions in dinoflagellate physiology, ecology, toxicity, and evolution while providing valuable information on a significant public health and economic problem.Broader Impacts. This project lends itself to undergraduate, graduate, and postdoctoral training. PI Anderson will support a PhD student on this project and will involve several undergraduate interns in the study as well. Anderson typically supports several Northeastern University interns who work in the laboratory for 6 months to obtain experience to guide education and career options. Postdoctoral Scholar Juliette Smith will participate in the toxin analysis, on a WHOI fellowship. The resulting culture collection will be shared with others working in this field to accelerate scientific progress. Project results will be broadly disseminated through scientific papers, presentations at workshops, conferences, and seminars, and discussions with the media. Furthermore, since the organisms being studied are responsible for a major form of shellfish poisoning that affects countries throughout the world, this project has significant practical implications that readily satisfy the criterion fostering connections between discoveries and their use in the service of society.