Genomic Analysis of Seed Quality Traits in Corn

美国约85%的玉米收成被用作动物饲料，因此发展高能饲料与美国经济高度相关。脂肪是细胞中最集中的能量来源。伊利诺伊大学进行的长期努力已经产生了含油量约为20%的管线(伊利诺伊州高油或IHO)以及含油量低于2%的管线(伊利诺伊州低油或IHO)。这些品系保留了很高水平的遗传多样性，初步的作图研究表明，大量基因与这一重要性状有关。这项研究的目标是确定参与这一遗传轨迹的所有基因。这项研究计划将使用一种“候选基因方法”来确定可能在玉米脂肪沉积中发挥重要作用的基因。这种方法的第一步是使用平行基因表达分析作为一种工具来识别在IHO和LIO玉米中表达水平发生变化的基因。通过利用大量具有胚胎和胚乳发育缺陷的玉米突变体，应该可以鉴定出大量共享共同发育表达程序的基因。一些玉米品系也被发现可以“改变”IHO性状的幅度(即含有IHO基因修饰基因的玉米品系)。这些玉米品系也可能有助于寻找与高油组分相关的候选基因。前述方法将识别许多候选基因。为了将候选基因的数量减少到较少的“极有可能”的候选基因，将使用一些策略来定位与高油价性状相关的单基因突变。这些将依赖于尖端的突变检测技术。两种策略将被用来将单核苷酸突变与高油性状的组成部分联系起来：第一种策略是单核苷酸突变与高油性状成分之间的“直接关联”；第二种策略是单核苷酸突变与IHO基因之间的“间接关联”。这两种策略都将利用伊利诺伊大学开发的植物遗传资源，以高分辨率绘制IHO x iLO杂交的DNA多态图谱。除了研究目标外，该研究计划还旨在培训基因组学方面的研究生和博士后研究员。学生将获得每人两名论文导师的好处，每名PI将担任至少两名学生的联合导师。

About 85% of the U.S. corn harvest is used as animal feed, therefore the development of "high energy feeds" is highly relevant to the economy of the United States. Fats are the most concentrated source of energy in the cell. The long term effort conducted at the University of Illinois has resulted in lines with about 20% oil (Illinois High Oil or IHO) as well as lines with less than 2% oil (Illinois Low-Oil or IHO). These lines have retained a very high level of genetic diversity and preliminary mapping studies suggest that a large number of genes are involved in this important trait. The goal of the research is to identify all of the genes that are involved in this genetic trait.This research program will use a "candidate gene approach" to identify genes that may play a significant role in oil deposition in corn. The first step of this approach consists of using parallel gene expression analysis as a tool to identify genes whose expression levels are altered in IHO vs ILO maize. By using the large collection of maize mutants with defects in embryo and endosperm development it should be possible to identify a large number of genes that share common developmental expression programs. A number of maize lines have also been found that can "modify" the amplitude of the IHO trait (i.e., lines of corn that contain modifier genes for the IHO genes). These lines of maize could also be useful in finding candidate genes associated with components of the high oil traits.The aforementioned approach will identify many candidate genes. To reduce this number of candidates to a smaller number of "highly probable" candidates genes, a number of strategies will be used to map single gene mutations relative to the high oil trait. These will rely on cutting edge mutation detection technologies. Two strategies will be used to associate single nucleotide mutations and components of the high oil trait:The first will consist of a "direct association" between single nucleotide mutations and components of the high oil trait.The second will consist of an "indirect association" between single nucleotide mutations and IHO genes.Both of these strategies will exploit the plant genetic resources developed by the University of Illinois for high resolution mapping of DNA polymorphisms in IHO x ILO crosses.In addition to the research goal, this research program is designed to train graduate students and post-doctoral fellows in the science of genomics. The students will have the benefit of having two thesis advisors each and each PI will serve as a co-advisor to a minimum of 2 students.