Epigenetic stability and its evolutionary potential

这项研究将研究环境条件如何改变基因表达模式并传递给后代，从而影响进化过程。环境条件可以引起个体特征的变化，包括其形态、生理、发育和行为。这种环境影响可能是短暂的，也可能持续整个生命周期，甚至超过一代人。研究这种影响对于我们理解进化过程至关重要，特别是因为它可能受到气候变化的影响。表观遗传学是指改变遗传序列如何翻译成功能性基因产物的机制，某些表观遗传机制与环境对个体特征的影响有关。有人认为，跨代稳定的表观遗传修饰可能是自然选择可以发挥作用的遗传变异的重要来源，而且这种变异甚至可能在环境背景和适应价值方面是非随机的。这一假设提出了一些令人信服的问题。首先，哪些表观遗传变化是环境诱导的，环境依赖性变化与独立性变化在遗传稳定性方面是否不同？第二，表观遗传变异的稳定性本身是可遗传的吗？第三，表观遗传修饰的稳定性是适应性的吗？如果是，在什么条件下？此外，该项目将培训从高中到研究生院的学生，并促进研究生和博士后学者的国际参与。该研究计划将使用拟南芥来测试全基因组甲基化状态稳定性的自然变异，以测试这种稳定性是否取决于环境条件，并测试环境诱导的甲基化状态变化是否比不响应环境条件的甲基化更稳定或更不稳定。因此，它测试的预测，环境引起的表观遗传变化可能是一个重要的来源，可遗传的表型变异，可以有助于适应性进化。其次，甲基化状态、其稳定性和其环境可逆性的QTL分析将测试甲基化稳定性是否具有遗传基础。它还将提供关于由给定QTL调节的甲基化状态的数量的信息，并且它将测试在代内和跨代调节甲基化稳定性的基因座是否与调节其环境可逆性/稳定性的基因座遗传相关。最后，该研究将测试调节甲基化状态及其稳定性的基因座是否也与适应性显著的表型以及恒定和可变环境下的适应性本身相关。这项研究的目标是表观遗传变化的稳定性作为一个关键的表型，通过测试表观遗传稳定性是否具有遗传基础，以及它是否适应稳定和可变的环境。

This study will examine how environmental conditions that alter patterns of gene expression and are passed to offspring can influence the process of evolution. Environmental conditions can cause changes in the characteristics of individuals, including their morphology, physiology, development, and behavior. Such environmental effects can be ephemeral, or they can persist for whole lifespans or even beyond a single generation. Studying such effects is central to our understanding of the process of evolution, especially as it might be affected by climate change. Epigenetics refers to mechanisms that alter how genetic sequences are translated into functional gene products, and certain epigenetic mechanisms have been implicated in environmental effects on the characteristics of individuals. It has been argued that epigenetic modifications that are stable across generations can be an important source of genetic variation upon which natural selection can act, and that such variation may even be non-random with respect to environmental context and adaptive value. This hypothesis raises a number of compelling questions. First, which epigenetic changes are environmentally induced, and do environment-dependent versus independent changes differ in their stability of inheritance? Second, is the stability of epigenetic alterations itself heritable? Third, is the stability of epigenetic modifications adaptive, and if so, under what conditions? Additionally, this project will train students from high school to graduate school and promote international engagement by graduate students and post-doctoral scholars. The research program will use Arabidopsis thaliana to test for natural variation in the stability of genome-wide methylation states within and across generations, to test whether such stability depends on environmental conditions, and to test whether environmentally induced changes in methylation state are more or less stable than methylation that does not respond to environmental conditions. As such, it tests the prediction that environmentally-induced epigenetic changes can be an important source of heritable phenotypic variation that can contribute to adaptive evolution. Second, a QTL analysis of methylation states, their stability, and their environmental reversibility will test whether methylation stability has a genetic basis. It will also provide information on the number of methylation states that are regulated by a given QTL, and it will test whether loci that regulate methylation stability within and across generations are genetically associated with loci that regulate their environmental reversibility/stability. Finally, the research will test whether loci that regulate methylation states and their stability are also associated with adaptively significant phenotypes and with fitness itself under constant and variable environments. This research targets the stability of epigenetic changes as a key phenotype by testing whether epigenetic stability has a heritable genetic basis and whether it is adaptive under stable and variable environments.