CAREER: Regulation and Function of Imprinted Gene Expression in Seeds

植物种子是人类饮食的重要组成部分，在植物繁殖中也起着至关重要的作用。然而，关于种子如何发育和生长的确切分子细节还没有被很好地理解。这个项目的目标是促进我们对种子发育的理解，这反过来可能对作为营养食物来源的种子的生产产生有益的结果。该项目还将为高中教师、本科生、研究生和博士后提供遗传学、基因组学、生物信息学和分子生物学方面的跨学科教育和培训。高中科学教师将在实验室度过两个暑假，直接参与研究活动，并开发与植物生物学研究相关的探究性学习模块，他们将把这些模块带回课堂。这种伙伴关系将与教师建立长期的联系，以提高他们的学生分析定量信息和从科学探索中产生知识的能力。开花植物的种子发育在一定程度上受到印记基因的调控。基因印迹是一种表观遗传现象，基因的等位基因的表达取决于它们是从父本遗传还是从母本遗传来的。为了理解和操纵种子生物学的有益效果，需要破译印记基因表达的调节和功能。最近的研究已经创建了不同植物物种的印记基因目录，并对印记的程度和受印记表达的基因类型产生了重要的见解。然而，目前尚不清楚是否所有的印记都是有功能的，或者印记的一些实例是否是由于全基因组表观遗传重新编程过程而发生的旁观者事件。本研究的主要目的是综合评价印记基因在种子发育中的功能，检验纯粹的表观遗传变异是否足以诱导印记变异，并了解利用印记表型的自然变异来调节印记的基因网络。这项研究将在进一步确定印记的功能后果以及理解调控印记表达的表观遗传机制、增加我们对种子生物学的理解以及自然变异在这些过程中的作用方面取得实质性成果。最后，将开发以序列特定的方式精确设计DNA甲基组的工具，允许直接测试特定的DNA甲基化模式是否对于印迹表达是必要的和充分的。这些工具有可能在其他动植物物种中发挥作用。

Plant seeds are an important part of the human diet, and they also play a vital role in plant reproduction. However, the precise molecular details of how seeds develop and grow are not well understood. The goal of this project is to advance our understanding of seed development, which in turn could have a beneficial outcome for production of seeds as a nutritious food source. The project will also provide interdisciplinary education and training in genetics, genomics, bioinformatics, and molecular biology for high school teachers, undergraduates, graduate students, and postdoctoral fellows. High school science teachers will spend two summers in the laboratory, participating directly in research activities and developing inquiry-based learning modules related to plant biology research, which they will bring back to their classrooms. This partnership will establish long-term connections to teachers to increase their students' ability to analyze quantitative information and generate knowledge from scientific exploration. Seed development in flowering plants is regulated, in part, by genes that are imprinted. Gene imprinting is an epigenetic phenomenon whereby alleles of genes are differentially expressed depending on whether they are inherited from the male or female parent. To understand and manipulate seed biology to beneficial effect requires deciphering the regulation and function of imprinted gene expression. Recent studies have created catalogues of imprinted genes in diverse plant species, and have yielded important insights about the extent of imprinting and the types of genes subject to imprinted expression. However, it remains unclear whether all imprinting is functional, or whether some instances of imprinting are bystander events due to genome-wide epigenetic reprogramming processes. The major aims of this research project are to comprehensively evaluate the function of imprinted genes in seed development, to test whether pure epigenetic variation is sufficient to induce imprinting variation, and to understand the gene networks that regulate imprinting by taking advantage of natural variation in imprinting phenotypes. This research will have substantial outcomes in further determining the functional consequences of imprinting and in understanding epigenetic mechanisms that regulate imprinted expression, increasing our understanding of seed biology and role of natural variation in these processes. Finally, tools to precisely engineer the DNA methylome in a sequence specific manner will be developed, allowing a direct test of whether specific DNA methylation patterns are necessary and sufficient for imprinted expression. These tools have the potential to be functional in other plant and animal species.