Functional Genomics of Physiological Plasticity

在自然界中，生物体会遇到各种各样的环境应激源，如温度、氧气供应或污染物。生物体使用不同的策略来应对和补偿这些应激源的影响，一些生物体比其他生物体有更好的补偿能力。表型可塑性是指具有相同基因组成的生物在不同环境条件下具有不同特征(表型)的能力。可以容忍更广泛环境极端的个体被认为比耐受范围更窄的生物更具表型可塑性。该项目研究了实现可塑性的基本机制，并将尝试确定塑料生物与敏感生物的特征，从而使它们能够耐受广泛的环境。基因表达(基因的开启和关闭)是生物体对环境变化做出反应的一个基本水平，因此，物种特定基因表达的差异可能是解释为什么一些物种比其他物种更具可塑性的重要原因。由于对环境盐度胁迫的补偿对所有水生生物来说都是必不可少的，该项目将重点放在千年鱼(Fundulus)物种内和物种之间对盐度挑战的基因表达反应和生理反应。这些鱼类为解决这些问题提供了一个强大的比较系统，因为Fundulus的种群和物种在补偿盐分胁迫的能力方面存在差异。一些物种完全生活在淡水中，对盐分几乎没有耐受性(低塑性)，另一些物种专门生活在海洋环境中，不能容忍淡水(低塑性)，还有一些物种生活在河口，可以容忍从淡水到海水四倍强度的整个连续体的盐度(高塑性)。这项研究设计的可比性将允许使用进化工具来区分与生理相关性不大的基因表达差异，以及那些似乎在功能上与生理补偿和可塑性相关的差异。最终，这些研究可能会洞察为什么一些生物可以忍受动态的环境，并有助于解释为什么一些物种比其他物种更有可能在快速的环境变化中生存下来。这个项目将包括对研究生和本科生进行现代基因组工具的培训。实验数据将被用作一门名为生态基因组学的新研究生课程的教学工具。动手培训将加强学生的学习，并使年轻的研究人员做好准备，以便利用基因组工具和方法进行自己的研究。该项目将促进对研究生和本科生的跨学科培训，并促进科学界代表性不足的群体的参与。

In nature organisms encounter a wide variety of environmental stressors, such as temperature, or oxygen availability, or pollutants. Organisms use diverse strategies to cope and compensate for the impact of these stressors, and some organisms are better able to compensate than others. Phenotypic plasticity is the ability of organisms with the same genetic makeup to have different characteristics (phenotypes) under different environmental conditions. Individuals that can tolerate wider environmental extremes are considered to be more phenotypically plastic than organisms that have more narrow tolerance ranges. This project examines fundamental mechanisms that enable plasticity, and will attempt to determine the characteristics of plastic organisms compared to sensitive organisms, which enables their tolerance of wide range of environments. Gene expression (the turning on and off of genes) is a fundamental level at which organisms respond to changes in the environment, thus species-specific differences in gene expression may be important for explaining why some species are more plastic than others. Because compensation for environmental salinity stress is essential for all aquatic organisms, this project will focus on gene expression responses and physiological responses to salinity challenges within and among species of the killifish, Fundulus. These fish provide a powerful comparative system for addressing these questions as populations and species of Fundulus vary in their ability to compensate for salinity stress. Some species live exclusively in freshwater have little tolerance for salt (low plasticity), others live exclusively in marine environments and cannot tolerate fresh water (low plasticity), and yet others live in estuaries and can tolerate salinities across the entire continuum from freshwater to four-times the strength of seawater (high plasticity). The comparative nature of this study design will allow the use of evolutionary tools to distinguish gene expression differences that have little physiological relevance from those that appear functionally related to physiological compensation and plasticity. Ultimately, these studies may yield insight into why some organisms can tolerate dynamic environments, and help explain why some species are more likely to survive rapid environmental change than others.This project will include the training of graduate and undergraduate students in modern genomic tools. Data from experiments will be used as a teaching device for a new graduate course entitled Ecological Genomics. Hands-on training will enhance student learning and prepare young investigators to take advantage of genomic tools and approaches for their own research. This project will promote interdisciplinary training for graduate and undergraduate students and promote participation of groups under-represented in science.