Mutational variance of the transcriptome and the origins of phenotypic plasticity

这项研究旨在确定基因突变发生的频率，它们是否会改变基因活性水平对环境的反应，以及这些改变的反应是否对可观察的特征有影响。这项研究将深入了解生物之间的遗传差异是如何产生的，这是所有进化变化和生命多样性的基础。生物之间的差异部分是由它们基因的差异以及基因信息用于构建蛋白质和其他细胞结构的速度的差异，以及这些基因的活性所驱动的。遗传差异的产生是由于复制储存遗传信息的分子DNA时产生的错误。如果这些错误发生在导致个体后代的细胞分裂过程中，那么这些差异将被所有后代继承。一个并行的教育活动将开发一个基于计算机的应用程序，模拟音乐背景下的复制错误。当学生学习遗传学时，他们通常一开始就对突变有一些误解。然而，说明突变特性的现实实验很难在课堂设置中执行。因此，该项目包括“突变音乐”的开发，这是一个移动设备的应用程序，使用基于计算机的音乐来模拟自发突变，以及一个适合在介绍性遗传学实验室使用的教育程序。自发突变是遗传变异的最终来源；因此，了解它们的特征是生物学家的一个基本目标。现有的工作已经量化了自发突变的速率和影响，通常集中在突变的分子谱或适应度效应上。这些焦点是广泛分离的，并且将分子突变与适应度效应联系起来的过程受到的关注较少。该项目旨在弥合适应度和突变分子谱之间的差距，重点关注转录组的突变变化和关键生活史性状的表型可塑性。本研究对模式甲壳类水蚤进行了突变积累实验，并对不同资源环境下水蚤的基因表达和生活史性状进行了分析。这项工作将产生对每个基因表达的突变变异和遗传力的估计，包括识别等位基因特异性和剪接变异特异性的能力。此外，该工作将量化自发突变对生活史特征及其可塑性的影响分布。这些成分将被结合起来研究表达突变对表型可塑性起源的影响。

This research seeks to determine how often genetic mutations occur, whether they produce a change in how gene activity levels respond to the environment, and whether those altered responses have effects on observable traits. This study will provide insight into how genetic differences among organisms arise, the basis for all evolutionary change and the diversity of life. Differences among organisms are driven, in part, by differences in their genes and differences in the rate at which genetic information is used for the building of proteins and other cell structures, the activity of those genes. Genetic differences arise due to errors made when copying DNA, the molecule in which genetic information is stored. If these errors happen during cell divisions that lead to an individual's offspring, the differences will be inherited by all future generations. A parallel educational activity will develop a computer-based application that simulates copying errors in the context of music. When students learn genetics, they often begin with several misconceptions about mutations. However, realistic experiments illustrating properties of mutations are difficult to execute in class settings. Therefore, the project includes development of "Mutational Music", an application for mobile devices that uses computer-based music to simulate spontaneous mutations, along with an educational program appropriate for use in introductory genetics laboratories.Spontaneous mutations are the ultimate source of genetic variation; understanding their characteristics is therefore a fundamental goal of biologists. Existing work has quantified the rate and effects of spontaneous mutations, usually focusing on the molecular spectrum of mutations or on fitness effects. These foci are widely separated, and the processes that link molecular mutations to fitness effects have received less attention. This project is aimed at bridging the gap between fitness and the molecular spectrum of mutations, focusing on mutational changes in the transcriptome and in phenotypic plasticity of key life history traits. The research involves a mutation accumulation experiment in the model crustacean Daphnia pulex, coupled with analyses of gene expression and life history traits made in distinct resource environments. The work will generate estimates of the mutational variance and heritability of expression for each gene, including the ability to identify allele-specificity and splice variant-specificity. In addition, the work will quantify the distribution of effects spontaneous mutations have on life history traits and their plasticity. The components will be joined to investigate the potential that expression mutations contribute to the origin of phenotypic plasticity.