Mechanisms of stress adaptation in fish: the role of changes in gene expression

压力是所有生物体生活的一个重要方面。对压力的研究在具有社会、美学或经济重要性的鱼类等水生物种中尤为重要。应激可由外部物理或生物环境或有机体进行的某些过程(例如，捕获猎物、进食、交配等)施加。虽然按照现代人类生活的标准，压力一词已经有了负面的内涵，但并不是所有的压力都是坏的。当有机体能够通过激活一系列适应来消除或减轻压力时，压力可以被视为积极的(所谓的“正应激”)。只有当这些应对机制被超过时，压力才会变成一种负面的(痛苦)。这项建议描述了旨在更好地从机制上理解几种鱼类(蟾鱼及其近亲、角鲨和彩虹鲑鱼)压力的比较实验。直到最近，生物学家还不得不通过一次检查一个基因或基因家族来研究鱼类对压力的反应。然而，通过广泛的DNA测序和微阵列(芯片)实验，我们现在能够一次研究单个有机体中数千个基因的反应。因此，这项研究将扩展我们过去研究单基因(主要是氮废物产生和排泄的基因)的方法，利用基于微阵列的方法来研究多个基因对胁迫的反应。我们将检查的压力/过程是拥挤压力、暴露在空气中、暴露在氨中、摄入大量零星食物、缺氧和锻炼。通过对大量基因、多种物种和多种应激源的研究，我们希望获得对所有应激共有的基因、只针对某些应激的基因的更广泛的理解，以及更广泛的应激是如何作用于改变鱼类基因表达模式的。

Stress is an important aspect of life for all organisms. The study of stress is especially important in aquatic species such as fish that are of societal, aesthetic or economic importance. Stress can be imposed by the external physical or biological environment, or some process that an organism undertakes (e.g., prey capture, feeding, mating, etc.). While the term stress has come to have a negative connotation by the standards of modern human life, not all stress is bad. Stress can be viewed as a positive when an organism is capable of coping with stress by activating a series of adaptations to remove itself from or mitigate the stress (so-called 'eustress'). It is only when these coping mechanisms are exceeded that stress becomes a negative (distress). This proposal describes comparative experiments aimed at a better mechanistic understanding of stress in several species of fish (toadfish and its relatives, dogfish sharks, and rainbow trout). Until recently, biologists have had to study reactions of fish to stress by examining one gene or gene family at a time. However, through extensive DNA sequencing and microarray (chip) experiments, we are now able to study the responses of  literally thousands of genes in a single organism at a time. Therefore, this research will extend our past approach of examining single genes (primarily those of nitrogen waste production and excretion) with the microarray-based approaches to study multiple gene responses to stress. The stresses/processes we will examine are crowding stress, air-exposure, ammonia exposure, ingestion of large sporadic meals, hypoxia and exercise. Through studies of large numbers of genes, multiple species and multiple stressors, we hope to gain a broader appreciation of the genes that are common to all stresses, the genes that are specific to only some stresses, and more generally how stress acts to change patterns of gene expression in fish.