Transcriptional Silencing and Enhancing Mechanisms in Maize

DNA或与DNA相关的蛋白质的修饰（称为表观遗传标记）可以导致某些基因在生长和发育的不同阶段打开或关闭（基因调控）。 该项目将定义一种基于表观遗传学的基因调控模式，该模式在所有生物体中知之甚少，使用玉米作为模型系统，玉米是美国人类和动物消费以及生物能源生产的重要农产品。 由于这些表观遗传标记是可遗传的，可用于开启具有所需性状的基因，因此该项目可能会发现用于农业目的的玉米新品系工程的新方法。 该项目将吸引高中生参加暑期研究项目，并为研究生和本科生提供研究经验和培训。将通过连续染色质免疫沉淀（ChIP）从玉米中已知的表观遗传调控序列中分离蛋白质。 它们将与处于转录活性和沉默状态的DNA的ChIP样品进行比较，沿着已知调控序列的特异性缺失。 总的来说，这将用于阐明与转录沉默和激活相关的特定蛋白质-DNA相互作用。 由于调控序列参与等位基因通讯，因此还将鉴定与等位基因通讯相关的表观遗传调控相关的蛋白质。 这些相互作用的分析将提供深入了解真核生物中的转录沉默，增强子和副突变的机制，并解决组合表观遗传调控的复杂性。

Modifications (called epigenetic marks) of DNA or of the proteins associated with DNA can cause certain genes to be turned on or off (gene regulation) at different stages of growth and development. This project will define a mode of epigenetic-based gene regulation that is poorly understood in all organisms using as a model system maize (corn), which is an important agricultural product for human and animal consumption and for bioenergy production in the US. Since these epigenetic marks are heritable and can be used to turn on genes with desired traits, this project may uncover novel approaches for engineering new strains of corn for agricultural purposes. This project will engage high school students in summer research programs, and offer research experiences and training to graduate and undergraduate students. Proteins will be isolated by sequential chromatin immunoprecipitation (ChIP) from a known epigenetic regulatory sequence in maize. They will be compared from ChIP samples of DNA in transcriptionally active and silenced states, along with specific deletions of the known regulatory sequence. Collectively, this will be used to elucidate the specific protein-DNA interactions associated with transcriptional silencing and activation. Because the regulatory sequence participates in allelic communication, proteins involved with epigenetic regulation associated with allelic communication will also be identified. Analysis of these interactions will provide insight into mechanisms of transcriptional silencing, enhancers, and paramutation in eukaryotes and address the complexity of combinatorial epigenetic regulation.