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，几乎所有具有重要商业价值的物种都直接或间接依赖于富含脂肪的桡足类(长足类、尾足类、尾足类和沼虾)。反过来，这些物种依靠短暂的春季藻类水华生长和积累脂肪储备，以完成包括休眠期在内的年度生命周期。该项目的主要目的是通过实地观察和实验观察相结合的方法，衡量藻类水华的时间和大小对休眠准备的影响。阿拉斯加州北部海湾有四种金枪鱼，它们经历了休眠，环境梯度陡峭，浮游植物水华动态得到了很好的描述，同时还有一个NSF-LTER计划--为确定影响休眠准备的因素提供了一个不同寻常的机会。教育和外展计划与研究相结合。教育工作的重点是为本科生、研究生和博士后实习生提供跨学科的机会。该项目将为现有的研究生和本科课程提供内容。阿拉斯加州大学费尔班克斯分校和马诺阿的夏威夷分校都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与该项目。由于捕捞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挂钩的动态食物网的概念，宣传桡足类在海洋生态系统中发挥的作用。滞育(休眠)和随之而来的桡足类中脂肪的积累已被确定为高纬度生态系统中支持重要经济渔业的关键驱动因素，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种群的严重减少有关，但人们对成功完成桡足类动物生命周期所需的环境条件知之甚少。一种测量相对基因表达的生理图谱方法将被用来检验两种替代假说：脂肪积累窗口假说和发育程序假说，前者认为个体只有在积累了足够的脂肪储存后才进入滞育状态，后者认为一旦滞育程序被激活，进展发生时不依赖于脂类积累。具体目标是：1)利用多种生理和发育标记，确定不同食物水平对滞育进程的影响；2)描述不同环境梯度和不同年龄段的不同季节弗氏原甲鱼生理分布的变化；3)比较不同共生种类(弗莱明鱼、长尾新银鱼、新银鱼和马尾鱼)之间的生理变化；4)估计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现有的数据库公开提供，以及开发新的工具来常规获取桡足类的生理特征。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.