Mechanisms of Animal Desiccation Tolerance

含水量的波动是所有动物面临的普遍问题，影响动物细胞中含水量的环境压力对生命构成威胁。 对水分胁迫的耐受性很可能由几种不同的机制控制，这些机制在失水期间保护细胞和组织，以及在补液后修复损伤。 然而，对这些机制的科学理解是不完整的。 本项目将研究某些类型的天然蛋白质[晚期胚胎发育丰富（莱亚）蛋白质]与小的糖样化合物结合时，是否能够在失水和随后的恢复过程中保护细胞成分、分离的细胞和完整的动物。 预计这些莱亚蛋白质和糖可以保存 生物结构，因为它们在对水分流失具有极端耐受性的物种（脱水生物动物）中被反复发现。 这些蛋白质和糖可以稳定细胞组分的结构和功能的机制（例如，酶、膜、线粒体）将使用生物化学、生理学和遗传学方法进行研究。 预期的结果是，不具有对干燥胁迫耐受性的细胞和组织将受到莱亚蛋白和糖的保护，免受通常在失水期间引起的损害。 该项目的成功完成有可能提供重要的实际应用。 例如，生物成分和细胞在干燥状态下的储存将延长其保质期，这可以为基础和应用领域的科学研究人员节省大量时间、精力和金钱。 研究人员使用果蝇（Drosophila melanogaster）等模式物种进行遗传研究，将极大地受益于将早期发育阶段储存在干燥（休眠）状态的能力，从而降低了维持该物种遗传变异的成本。 最后，该项目将为来自生物化学，生理学和分子遗传学领域广泛背景的本科生和研究生的培训和教育提供令人兴奋的机会。

Fluctuation in water content is a universal problem confronting all animals, and environmental stresses that impact the amount of water present in the cells of animals pose a threat to life. Tolerance to water stress is most likely governed by several different mechanisms that are in place to protect cells and tissues during water loss, as well as to repair injuries after rehydration. However, scientific understanding of these mechanisms is incomplete. This project will investigate whether or not certain types of naturally-occurring proteins [Late Embryogenesis Abundant (LEA) proteins], when combined with small sugar-like compounds, are able to protect cellular components, isolated cells, and intact animals during water loss and subsequent recovery. These LEA proteins and sugars are predicted to preserve biological structures because they have been repeatedly found in species that possess extreme tolerance to water loss (anhydrobiotic animals). The mechanisms by which these proteins and sugars may stabilize the structure and function of cellular components (e.g., enzymes, membranes, mitochondria) will be investigated using biochemical, physiological and genetic approaches. The anticipated result is that cells and tissues that do not possess tolerance to desiccation stress will be protected by LEA proteins and sugars against damage normally incurred during water loss. Successful completion of this project has the potential to offer important practical applications. For example, storage of biological components and cells in the dried state will extend their shelf-life, which could represent enormous savings of time, effort and money for scientific researchers in both basic and applied fields. Investigators using model species like Drosophila melanogaster (fruit fly) for genetic studies would benefit immensely from the ability to store early developmental stages in a dried (dormant) state, thereby reducing the costs of maintaining genetic variants of this species. Finally, this project will provide exciting opportunities for the training and education of undergraduate and graduate students from a wide diversity of backgrounds in the fields of biochemistry, physiology and molecular genetics.