DISSERTATION RESEARCH: A case study of evolution of epigenetic regulators post-gene duplication: Understanding EMBRYONIC FLOWER2-mediated gene regulation in a moss

基因复制是进化可以作用的新遗传物质的重要来源。新功能可以部分包括原功能，也可以完全是新功能。以苔藓中的胚胎花2 （EMF2）蛋白为例，新复制的基因可能针对新的基因进行抑制，或者它们可能针对原始目标的一个子集。这项研究具有重要的科学意义，因为它将作为一个模型来了解基因复制事件后调控基因的功能如何变化。此外，EMF2蛋白是控制陆地植物生命周期的重要蛋白质复合体的一部分。因此，了解emf2介导的基因调控的进化将有助于更好地理解陆生植物的发育进化。然而，EMF2基因不仅在植物进化中很重要——它们在动物发育中也是必需的。携带突变的EMF2基因或携带错误数量的EMF2蛋白的人通常会患上癌症。虽然人类和植物是远亲，但发现EMF2基因调控背后的保守机制将有助于我们对人类疾病的理解。其他影响包括指导和培训本科生，以及向K-12学校和公众推广。基因复制很重要，因为它是新蛋白质功能产生的主要机制。本研究旨在了解基因复制在基因调控进化中所起的作用。EMF2基因是重要的基因调节因子，确保基因在发育过程中的适当时间关闭和保持关闭。在许多植物谱系的进化过程中，EMF2基因经历了重复。一组复制事件在小立壶菌中产生了三个EMF2基因拷贝，小立壶菌是一种具有强大遗传和基因组资源的模式苔藓物种。本项目的目标是：1)通过基因复制事件的系统发育分析，了解苔藓谱系中EMF2基因的进化；2)通过分析三个小壶菌EMF2基因的突变体，了解它们各自的功能；3)通过确定每个EMF2拷贝靶向哪些基因以及EMF2靶向是否导致基因激活或抑制，了解小壶菌基因复制是如何改变EMF2基因调控机制的。总的来说，这项研究将提供基因复制后基因调控的进化的理解。

Gene duplication is an important source of novel genetic material on which evolution can act. The novel functions may partially include the original function or may be entirely novel. In the case of the EMBRYONIC FLOWER2 (EMF2) proteins in mosses, the newly duplicated genes may target new genes for repression or they may each target a subset of the original targets. This study is of scientific importance because it will serve as a model to understand how the function of regulatory genes change after a gene duplication event. Moreover, the EMF2 proteins are part of a protein complex that is important in controlling the life cycles of land plants. Thus, understanding the evolution of EMF2-mediated gene regulation will provide a better understanding of the developmental evolution of terrestrial plant life. The EMF2 genes, however, are not only important in plant evolution- they are necessary in animal development. Humans with mutated EMF2 genes or with the wrong amount of EMF2 protein will often develop cancer. Although humans and plants are distantly related, uncovering the conserved mechanisms behind EMF2 gene regulation will contribute to our understanding of human disease. Additional impacts include mentoring and training of undergraduates, along with outreach to K-12 schools and the general public. Gene duplication is important because it is the primary mechanism through which novel protein functions arise. This study aims to understand the role gene duplication has played in the evolution of gene regulation. The EMF2 genes are important gene regulators, ensuring that genes are turned off and remain off at the appropriate time during development. The EMF2 genes have undergone duplications during the evolution of many plant lineages. One set of duplication events has produced three copies of the EMF2 genes in Physcomitrella, a model moss species for which powerful genetic and genomic resources are available. The goals of this project are: 1) To understand the evolution of the EMF2 genes in the moss lineage by phylogenetic analysis of gene duplication events; 2) To understand the function of each of the three Physcomitrella EMF2 genes by analyzing mutants in these genes; and 3) To understand how the Physcomitrella gene duplications have modified the EMF2 gene regulation mechanism by determining which genes are targeted by each EMF2 copy and by determining whether this EMF2 targeting results in gene activation or repression. Overall, this study will provide an understanding of the evolution of gene regulation post-gene duplication.