Maize Gene Discovery, Sequencing and Phenotypic Analysis

将建立一个虚拟中心，由6所大学的10名研究人员组成(弗吉尼亚·沃尔伯特，斯坦福大学；维基·钱德勒，大卫·加尔布雷斯和布莱恩·拉金斯，亚利桑那大学；莎拉·哈克和迈克·弗里林，加州大学伯克利分校；罗伯特·施密特和劳里·史密斯，加州大学圣地亚哥分校；马丁·M·萨克斯，伊利诺伊大学；沃尔克·布伦德尔，爱荷华州立大学)。这些研究人员将对玉米中的每一个基因进行鉴定、测序并确定突变的效果。Walbot，即PI，多年来一直在研究一种可移动的遗传元件Mu转座子的调节。转座子是一段DNA，可以复制并插入到基因组中的其他位置。MU优先在基因内插入，这会导致突变。沃尔伯特博士开发了一个名为RescueMu的Mu版本，它将允许通过一个简单的一步过程来克隆插入位点两侧的DNA。这种方法为阐明基因序列和功能提供了一种非常有效的策略。将产生一个玉米植株群体，这些玉米植株在每个玉米基因中都包含RescueMu插入。这些植物将被筛选出形态异常。插入的RescueMu元件两侧的DNA将被分离和测序。总体而言，这种方法允许对玉米基因进行识别和测序，并对其功能中断的后果进行测试。作为鉴定在玉米中表达的基因的第二种方法，该项目将确定50,000多个cDNA的部分和完整序列；(cDNA是mRNAs的DNA拷贝)。研究人员将制造微阵列(固定DNA阵列)，用于调查每个基因在不同玉米品系和组织中的表达。最后，将开发一种简单的方法，将这些基因一步到位地定位到适当的玉米染色体上。在该项目期间开发的所有信息和生物材料将及时提供给玉米界。玉米是美国最重要的农作物，也是拟南芥的远亲。因此，在玉米中仍有许多新基因有待发现。很明显，通过这个项目发现的基因将影响重要的农艺性状。在项目过程中开发的信息和实验工具将对不仅研究玉米，而且研究水稻、高粱和其他作物的研究人员有价值。在该项目期间开发的RescueMu技术很可能会转移到其他重要的模式植物和农作物上。

A virtual center will be established, comprising 10 investigators at 6 universities (Virginia Walbot, Stanford University; Vicky Chandler, David Galbraith, and Brian Larkins, University of Arizona; Sarah Hake and Mike Freeling, University of California at Berkeley; Robert Schmidt and Laurie Smith, University of California at San Diego; Martin M. Sachs, University of Illinois; and Volker Brendel, Iowa State University). These investigators will identify, sequence, and determine the effects of mutating every gene in maize.Dr. Walbot, the PI, has studied the regulation of a mobile genetic element, the Mu transposon, for many years. Transposons are pieces of DNA that replicate and insert themselves at other sites in the genome. Mu inserts preferentially within genes, which causes mutations. Dr. Walbot has developed a version of Mu, called RescueMu, which will allow the DNA that flanks the insertion site to be cloned in a simple, one-step procedure. This approach allows a very powerful strategy for elucidating gene sequence and function.A population of maize plants will be generated that together contain RescueMu insertions in every maize gene. These plants will be screened for morphological abnormalities. The DNA flanking the inserted RescueMu elements will be isolated and sequenced. Overall, this approach allows maize genes to be identified and sequenced, and the consequence of disrupting their function to be tested. As a second approach to identify genes that are expressed in maize, this project will determine partial and complete sequences for more than 50,000 cDNAs; (cDNAs are DNA copies of mRNAs). The investigators will fabricate microarrays (arrays of immobilized DNAs) which will be used to survey expression of each gene in different maize lines and tissues. Finally, a simple method will be developed to map these genes to the appropriate maize chromosome in a single step. All information and biological materials developed during the project will be made available to the maize community in a timely fashion.Maize is the most important crop plant in the U.S., and is a distant cousin of Arabidopsis. Consequently, many new genes remain to be discovered in maize. It is clear that genes discovered through this project will affect agronomically important traits. The information and experimental tools developed in the course of the project will be valuable to researchers who study not only maize, but rice, sorghum, and other crops. The RescueMu technology that will be developed during this project will likely be transferable to other important model and crop plants.