Role of microRNA-related Polymorphisms in Regulating Heterotic Gene Expression

派：雷丽(弗吉尼亚大学)杂种优势是指不同自交系的后代表现出优于双亲之一的性状的现象。这一现象已被广泛应用于植物育种和作物改良中。虽然一些遗传概念早已被用来解释杂种优势，但它们还没有与分子原理相联系，因此提供的机制洞察力有限。该项目的目的是研究微RNA介导的基因回路在水稻杂种优势中的作用，该回路调节许多植物的发育过程。这项工作将利用水稻基因组序列、高通量实验技术、生物信息学工具和分子技术来研究1)两个亲本水稻品系之间与microRNA相关的多态如何影响其杂交后代的差异基因表达，以及2)操纵关键microRNA基因的表达水平是否影响杂种表型。通过这项计划，将确定一组与杂种优势有关的microRNA基因及其靶基因。从这项研究中获得的知识应该为理解microRNA介导的分子事件在杂种优势表达中的作用提供必要的框架，从而为进一步设计作物改良中的这一现象奠定基础。该项目的更广泛影响部分源于杂交作物生产的产量优势和其他优势特征。了解微RNA调控的基因回路在模式植物水稻杂种优势中的作用对世界范围内的粮食安全具有重要意义。将通过已建立的微型RNA数据库(http://microrna.sanger.ac.uk/)和水稻注释数据库(http://rice.plantbiology.msu.edu/).))向公众提供一套全面的经过实验测试的水稻微型RNA基因这些信息将为我们对microRNA介导的基因调控提供新的见解，并增加我们对植物基因组表达和调控的一般知识。鉴于水稻是草本植物的典范，从这个项目中获得的信息应该有助于进行比较基因组学研究，目的是追踪其他粮食、饲料和能源作物中由microRNA调节的基因电路的进化。该项目的更广泛影响还包括在植物基因组学和生物信息学的跨学科领域提供极好的培训机会。通过将课堂讲课与计算实验相结合，这个项目产生的信息将对鼓励本科生积极参与独立研究特别有用。

PI: Lei Li (University of Virginia)Heterosis (hybrid vigor) refers to the phenomenon that progeny of diverse inbred parent exhibits superior traits to either of the two parents. This phenomenon has been extensively exploited in plant breeding and crop improvement. Although several genetic concepts have long been used to explain heterosis, they are not yet connected with molecular principles and thus offer limited mechanistic insight. The goal of this project is to investigate the role of microRNA-mediated gene circuits, which regulate many plant developmental processes, in heterosis in the rice plant. This work will utilize the rice genome sequences, high throughput experimental techniques, bioinformatic tools, and molecular techniques to examine 1) how microRNA-related polymorphisms between two parental rice strains contribute to differential gene expression in their hybrids, and 2) whether manipulation the expression levels of key microRNA genes impacts heterotic phenotypes. Through this project, a set of microRNA genes and their target genes involved in heterosis will be identified. Knowledge gained from this research should provide a framework necessary to understand the role of microRNA-mediated molecular events in the expression of heterosis and thus a foundation for further engineering the phenomenon in crop improvement. The broader impacts of this project stem in part from the yield advantage and other superior traits of hybrid-based crop production. Understanding the contribution of microRNA-regulated gene circuits to heterosis in the model plant rice is of great importance to food security worldwide. A comprehensive set of experimentally tested microRNA genes in rice will be made available to the public through established microRNA databases (http://microrna.sanger.ac.uk/) and rice annotation databases (http://rice.plantbiology.msu.edu/). Such information will provide new insights into microRNA-mediated gene regulation and add to our general knowledge of plant genome expression and regulation. Given that rice is a model for the grass species, information obtained from this project should facilitate comparative genomics studies aimed at tracing evolution of microRNA-regulated gene circuits in other food, feed and energy crops. The broader impacts of this project also include excellent training opportunities in the interdisciplinary field of plant genomics and bioinformatics. By blending classroom lectures with computational experimentation, information generated from this project will be particularly useful to encourage undergraduate students to actively participate in independent research.