Collaborative Research: Molecular profiling of the ecophysiology of dormancy induction in calanid copepods of the Northern Gulf of Alaska LTER site

亚北极太平洋维持着主要的渔业，几乎所有商业上重要的物种都直接或间接地依赖于富含脂肪的桡足类动物（Neocalanus flemingeri, Neocalanus plumchrus， Neocalanus cristatus和Calanus marshallae）。反过来，这些物种依赖于短暂的春季藻华生长和脂质储存的积累，以完成包括一段休眠期在内的年度生命周期。这个项目的知识主旨是通过实地和实验观察相结合来测量藻华的时间和大小如何影响冬眠的准备。阿拉斯加北部海湾有四种calanid，它们经历休眠，陡峭的环境梯度，描述良好的浮游植物繁殖动态，以及同时进行的NSF-LTER计划，为确定影响休眠准备的因素提供了一个不寻常的机会。教育和推广计划与研究相结合。教育工作的重点是为本科生、研究生和博士后学员提供跨学科的机会。该项目将为现有的研究生和本科生课程生成内容。阿拉斯加大学费尔班克斯分校和夏威夷大学马诺阿分校是阿拉斯加原住民和夏威夷原住民服务机构，这些团体的学生将被招募参加该项目。由于渔业是阿拉斯加湾的一项主要产业，外联活动将利用与生产周期相关的动态食物网的概念，宣传桡足类动物在海洋生态系统中的作用。桡足类动物滞育（休眠）和伴随的脂质积累已被确定为高纬度生态系统的关键驱动因素，这些生态系统支持经济上重要的渔业，包括阿拉斯加湾的渔业。虽然富含脂肪的桡足类动物的消失与鱼类资源的严重减少有关，但人们对桡足类动物成功完成生命周期所需的环境条件知之甚少。测量相对基因表达的生理分析方法将用于测试两种可供选择的假设：脂质积累窗口假说，该假说认为个体只有在积累了足够的脂质储存后才进入滞育，以及发育程序假说，该假说认为一旦滞育程序被激活，发育过程就独立于脂质积累而发生。具体目的是：1)利用多种生理和发育标志物确定不同食物水平对桡足奈米虫滞育进程的影响；2)研究了不同环境梯度和不同年份下黑穗草生理特征的季节变化特征；3)比较共生Calanus物种（N. flemingeri, Neocalanus plumchrus， Neocalanus cristatus和Calanus marshallae）的生理特征；4)估算了越冬种群的繁殖潜力。更广泛的科学意义包括获取新的基因组数据和分子资源，这些数据和分子资源将通过已建立的数据库公开提供，以及开发用于常规获取桡足类生理特征的新工具。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The sub-arctic Pacific sustains major fisheries with nearly all commercially important species depending either directly or indirectly on lipid-rich copepods (Neocalanus flemingeri, Neocalanus plumchrus, Neocalanus cristatus and Calanus marshallae). In turn, these species depend on a short-lived spring algal bloom for growth and the accumulation of lipid stores in order to complete an annual life cycle that includes a period of dormancy. The intellectual thrust of this project measures how the timing and magnitude of algal blooms affect preparation for dormancy using a combination of field and experimental observations. The Northern Gulf of Alaska - with four calanid species that experience dormancy, steep environmental gradients, well-described phytoplankton bloom dynamics, and a concurrent NSF-LTER program - provides an unusual opportunity to identify the factors that affect dormancy preparation. Education and outreach plans are integrated with the research. Educational efforts focus on interdisciplinary opportunities for undergraduate, graduate and post-doctoral trainees. The project will generate content for existing graduate and undergraduate courses. U. of Alaska Fairbanks and U. Hawaii at Manoa are Alaska Native and Native Hawaiian Serving Institutions, and students from these groups will be recruited to participate in the project. Because fishing is a major industry in the Gulf of Alaska, outreach will communicate the role copepods play in marine ecosystems using the concept of a dynamic food web tied to production cycles.Diapause (dormancy) and the accompanying accumulation of lipids in copepods have been identified as key drivers in high latitude ecosystems that support economically important fisheries, including those of the Gulf of Alaska. While the disappearance of lipid-rich copepods has been linked to severe declines in fish stocks, little is known about the environmental conditions that are required for the successful completion of the copepod's life cycle. A physiological profiling approach that measures relative gene expression will be used to test two alternative hypotheses: the lipid accumulation window hypothesis, which holds that individuals enter diapause only after they have accumulated sufficient lipid stores, and the developmental program hypothesis, which holds that once the diapause program is activated, progression occurs independent of lipid accumulation. The specific objectives are: 1) determine the effect of food levels during N. flemingeri copepodite stages on progression towards diapause using multiple physiological and developmental markers; 2) characterize the seasonal changes in the physiological profile of N. flemingeri across environmental gradients and across years; 3) compare physiological profiles across co-occurring calanid species (N. flemingeri, Neocalanus plumchrus, Neocalanus cristatus and Calanus marshallae); and 4) estimate the reproductive potential of the overwintering populations of N. flemingeri. The broader scientific significance includes the acquisition of new genomic data and molecular resources that will be made publicly available through established data repositories, and the development of new tools for routinely obtaining physiological profiles of copepods.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.