Genetic Mechanisms Underlying Quantitative Traits in Maize - Dosage Effects & Loss of Function Mutations

玉米数量性状的遗传机制——剂量效应

• 批准号: RGPIN-2014-05673
• 负责人: Lee, Elizabeth
• 金额: $ 1.89万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657010
• 关键词: Genetic; Mechanisms; Underlying; Quantitative; Traits

Loss of gene function is a mechanism by which quantitatively inherited traits respond to selection is the underlying premise of this DG research proposal. This premise was built on observations made while working with a maize Zea mays L.) population under long-term selection, builds upon my group's previous research, and continues the examination of genetic architecture underlying quantitative traits in maize.**Three distinct yet interconnected hypotheses will be examined in this proposal. They are distinct in that they involve very different traits - starch synthesis, ear development, leaf number and flowering time. They are connected in that they involve single-gene loss of function alleles and are potentially involved in altering meristem development. Specifically: (1) The short-ear phenotype was achieved by accumulating & maintaining a set of LOF alleles for genes involved in ear development in a heterozygous state thus effectively reducing the level of expression of these genes (i.e., gene dosage) and resulting in a short-ear phenotype. (2) Modifier of amylose extender 1 (mae1) is a LOF mutation that confers a moderately higher level of amylose. (3) Selection for an altered shoot apical meristem (SAM) based relationship between leaf number and flowering time will be achieved through the accumulation of LOF mutations.**Impact of this research is both in the applied and basic knowledge arenas. It will serve as a training ground for 2 M.Sc. students, 1 Ph.D. student, and 5 undergraduate students. And it will lead to the development of novel intellectual property in the form of maize germplasm exhibiting altered SAM based relationship between leaf number and flowering time.

基因功能丧失是数量遗传性状对选择做出反应的一种机制，是本 DG 研究提案的基本前提。这个前提是建立在对长期选择下的玉米（Zea mays L.）群体进行研究时进行的观察的基础上的，建立在我的小组之前的研究基础上，并继续对玉米数量性状背后的遗传结构进行检查。**本提案将检查三个不同但相互关联的假设。 它们的独特之处在于它们涉及非常不同的性状——淀粉合成、穗发育、叶子数量和开花时间。 它们之间的联系在于它们涉及单基因功能丧失等位基因，并可能参与改变分生组织的发育。 具体来说：（1）短耳表型是通过以杂合状态积累和维持一组参与耳发育的基因的LOF等位基因来实现的，从而有效降低这些基因的表达水平（即基因剂量），从而形成短耳表型。 (2) 直链淀粉延伸剂 1 (mae1) 的修饰物是一种 LOF 突变，可赋予适度较高水平的直链淀粉。 (3) 通过 LOF 突变的积累，将实现基于叶数和开花时间之间关系的改变的茎尖分生组织 (SAM) 的选择。**这项研究的影响是在应用和基础知识领域。 它将作为 2 名理学硕士的培训基地。在读学生，博士1名学生 5 名，本科生 5 名。 它将导致玉米种质形式的新型知识产权的开发，该种质显示出改变的基于 SAM 的叶数和开花时间之间的关系。