Ion-transport mechanisms in adaptation to extreme salinities

这个项目研究了仅有的两种在内陆盐湖(如大盐湖)繁衍生息的动物物种，它们如何感知和应对环境含盐量的剧烈变化。卤虫幼虫和卤虾必须保持比它们的环境低得多的盐分含量，这是一个耗费精力的过程。然而，人们对它们实现这一独特壮举的细胞机制知之甚少。该项目的工作将推断这两种生物如何适应细胞机制，在强烈有利于相反的环境中保留水分和排出盐。能够比较和对比这些本质上不同的物种用来对抗这种环境压力的机制，将为它们的适应提供关键的见解。这项合作研究将德克萨斯理工大学健康科学中心和伊利诺伊州立大学的研究和教学联系在一起，将使研究生和本科生沉浸在严谨和跨学科的教育环境中，为本科生提供1)基于项目研究的课程和2)继续实验室研究的机会，从而为招收本科生进入生物研究领域创造了一条途径。除了他们在研究方法方面的标准培训之外。参与研究工作的研究生还将接受关于如何(在课程内)授课和(在实验室内)成为导师的独特培训。因此，这个项目完成了一个多层次的培训经验，既加强了本科生和研究生的科学技能，又为研究生提供了作为未来导师和教员的培训。该项目的结果将通过同行评议的出版物、受邀的演讲和科学会议上的演讲来传播。使卤虾和卤蝇幼虫适应极端盐度的离子传输机制在很大程度上仍不清楚。该项目利用生物信息学、生物化学和电生理学的新集成，来识别这种离子转运体，研究它们的功能特性，并揭示它们的作用和合作，使这些动物能够在所有其他动物都死亡的环境中茁壮成长。将检验三个独立研究目标中的几个假设：1)确定盐度较高的咸虾生存所需的离子转运体；2)确定盐度较高的盐度下卤虫生存所需的离子转运体；3)阐明与盐度适应有关的氨基酸取代的分子机制。对于AIMS 1和Amp；2，将通过转录组学在每个生物体中鉴定目标离子转运蛋白，并通过药物存活分析和siRNA方法以及已鉴定的转运蛋白在异源表达系统中的表达来评估它们的功能作用。在所有渗透调节动物的适应过程中，Na，K-ATPase起着至关重要的作用。大多数适应极端盐度光谱两端的动物在对运输的离子与这种蛋白质的相互作用至关重要的区域出现了激进的结构改变。为了测试这些修饰是否以及如何为携带它们的极端盐度适应动物提供适应优势，该项目的第三个目标专门评估具有与在适应动物中观察到的相同结构特征的Na，K-ATPase的化学计量和功能特性。研究生和本科生实习生将在这两个机构得到支持。这两个公益机构都有出色的记录，涉及本科生和研究生在科学发现方面，同时在高影响力的期刊上撰写文章。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。

This project studies how the only two animal species that flourish in inland salt lakes, like the Great Salt Lake, sense and respond to harsh changes in environmental salt content. Brine fly larvae and brine shrimp must maintain a much lower salt content than their environment, which is an energetically costly process. However, the cellular mechanisms by which they achieve this unique feat are poorly understood. The work in this project will deduce how these two organisms adapt cellular mechanisms to retain water and expel salt within environments that strongly favor the opposite. The ability to compare and contrast the mechanisms utilized by these substantially different species to combat this environmental stress will provide critical insights into their adaptation. This collaborative study links research and teaching at Texas Tech University Health Sciences Center and Illinois State University and will immerse graduate and undergraduate students in a rigorous and interdisciplinary educational setting, providing 1) a project-research-based course and 2) continuing laboratory research opportunities for undergraduates, thus creating a pathway to recruit undergraduate students into biological research. in addition to their standard training in research methods. The graduate students involved in the research efforts will also be provided with unique training on how to teach (within a course) and to become a mentor (within the laboratory). Thus, this project accomplishes a multilevel training experience that reinforces scientific skills at both the undergraduate and graduate levels, while providing training to graduate students as future mentors and faculty members. The results from this project will be disseminated by peer-reviewed publications, invited lectures, and presentations at scientific meetings.The ion-transport mechanisms that allow brine shrimp and brine fly larvae adaptation to extreme salinities remain largely unknown. This project utilizes novel integration of bioinformatics, biochemistry, and electrophysiology, to identify such ion- transporters, study their functional properties, and uncover their role and cooperation to allow these animals to thrive in an environment where all other animals die. Several hypotheses organized in three independent research aims will be tested: 1) Identify the ion transporters required for brine shrimp survival in high salinity 2) Identify the ion-transporters required for brine fly survival in high salinity 3) Elucidate the molecular mechanisms of amino acid substitutions linked to salinity adaptation. For aims 1 & 2, target ion-transport proteins will be identified in each organism by transcriptomics, and their functional role evaluated by pharmacological survival assays and siRNA methods and by expression of the identified transporters in heterologous expression systems. An essential player in the adaptation of all osmoregulating animals is the Na,K-ATPase. Most animals that adapt to both ends of the extreme salinity spectrum present radical structural modifications in regions that are critical for the interaction of the transported ions with this protein. To test if and how these modifications may provide an adaptive advantage to the extreme salinity-adapting animals that carry them, the third aim of this project specifically evaluates the stoichiometry and functional properties of Na,K-ATPases with the same structural specialties as those observed in adapting animals. Graduate and undergraduate student trainees will be supported at both institutions. Both PIs have outstanding track records involving undergraduate and graduate students in scientific discovery while authoring articles in high-impact journals.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.