Ion-transport mechanisms in adaptation to extreme salinities

该项目研究了在内陆盐湖（如大盐湖）中蓬勃发展的仅有的两种动物物种如何感知和应对环境盐含量的剧烈变化。盐水蝇幼虫和盐水虾必须保持比它们的环境低得多的盐含量，这是一个能量昂贵的过程。然而，它们实现这一独特壮举的细胞机制却知之甚少。该项目的工作将推断出这两种生物体如何适应细胞机制，以在强烈倾向于相反的环境中保持水分并排出盐。比较和对比这些基本上不同的物种对抗这种环境压力的机制的能力将为它们的适应提供重要的见解。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起来，并将使研究生和本科生沉浸在严格的跨学科教育环境中，提供1）基于项目研究的课程和2）继续实验室研究机会为本科生，从而创造了一条招收本科生进入生物学研究的途径。除了他们在研究方法方面的标准训练之外。 参与研究工作的研究生还将获得关于如何教学（课程内）和成为导师（实验室内）的独特培训。因此，该项目完成了一个多层次的培训经验，加强了本科和研究生水平的科学技能，同时为研究生提供培训，作为未来的导师和教师。该项目的成果将通过同行评议的出版物、特邀讲座和科学会议上的演讲进行传播。使卤虫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然未知。该项目利用生物信息学，生物化学和电生理学的新整合，以识别此类离子转运蛋白，研究其功能特性，并揭示其作用和合作，使这些动物能够在所有其他动物死亡的环境中茁壮成长。将测试三个独立研究目标中的几个假设：1）确定盐水虾在高盐度下生存所需的离子转运蛋白2）确定盐水蝇在高盐度下生存所需的离子转运蛋白3）阐明与盐度适应相关的氨基酸取代的分子机制。对于目标1和2，目标离子转运蛋白将在每种生物体中通过转录组学鉴定，并通过药理学存活测定和siRNA方法以及通过在异源表达系统中表达所鉴定的转运蛋白来评价其功能作用。Na，K-ATP酶是所有调节神经递质的动物适应环境的一个重要因素。大多数动物，适应极端盐度光谱的两端目前激进的结构修改的区域，这是关键的相互作用的运输离子与这种蛋白质。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性优势，本项目的第三个目的是专门评估Na，K-ATP酶的化学计量和功能特性，其具有与适应动物中观察到的相同的结构特征。研究生和本科生实习生将在这两个机构的支持。这两个PI都有出色的记录，涉及本科生和研究生的科学发现，同时在高影响力的期刊上撰写文章。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响力审查标准进行评估的支持。

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.