Epigenetic Control of a Maize Anthocyanin Regulatory Gene

每一个高等生物体的细胞，无论是植物还是动物，都面临着如何将所有DNA装入细胞核的问题，同时仍然允许基因进入RNA合成机制，以便在发育的适当时候打开这些基因。 解决这一难题的通用方法是将DNA缠绕在蛋白质周围，形成一种称为染色质的DNA-蛋白质复合物。松散缠绕的染色质中的基因可接近RNA合成机制并被活跃地表达，而紧密缠绕的染色质中的基因不太容易接近且无活性。 缠绕是由DNA或构成染色质的蛋白质的化学变化可逆地控制的。 了解这些化学变化是如何调节的是这个项目的重点。实验的目的是分析玉米基因的表达，PI-印迹，控制紫色色素的合成。Pl-印迹植物具有与比通常更紧密缠绕的染色质相关的杂色的色素沉着模式和对Pl-印迹DNA的化学改变的独特模式。为了了解这些染色质特征是如何控制的，已经分离出了色素沉着改变的突变体。为了研究这些突变体如何控制Pl-印迹的表达，将进行实验以确定它们在Pl-印迹染色质的DNA或蛋白质中诱导何种特定变化。 这些研究的结果将有助于我们了解基因表达如何在不同的生物体中被染色质控制，这些生物体在生长和发育过程中使用基于染色质的机制来调节基因。该项目将由研究生和本科生进行，因此将为学生提供遗传学和基因组学方面的强有力的培训，特别强调团队合作和协作。

The cells of every higher organism, whether plant or animal, face the problem of how to fit all their DNA into the nucleus while still allowing the genes to be accessible to the RNA synthesis machinery needed to turn those genes on at proper times in development. The universal solution to this dilemma is to wind the DNA around proteins to form a DNA-protein complex called chromatin. Genes in loosely wound chromatin are accessible to RNA synthesis machinery and are actively expressed, whereas genes in tightly wound chromatin are less accessible and are inactive. Winding is reversibly controlled by chemical alterations to the DNA or the proteins that make up the chromatin. Understanding how these chemical changes are regulated is the focus of this project. Experiments are aimed at analyzing the expression of the maize gene, Pl-Blotched, which controls the synthesis of purple pigments. Pl-Blotched plants have a variegated pattern of pigmentation that is associated with more tightly wound chromatin than usual and a unique pattern of chemical alteration to the Pl-Blotched DNA. To understand how these chromatin features are controlled, mutants with altered pigmentation have been isolated. To study how these mutants control the expression of Pl-Blotched, experiments will be conducted to determine what specific changes they induce in the DNA or proteins of Pl-Blotched chromatin. The results of these studies will contribute to our understanding of how gene expression can be controlled by chromatin in a diverse array of organisms that use chromatin-based mechanisms for regulating genes during growth and development. This project will be carried out by graduate and undergraduate students and will thus provide the students with strong training in genetics and genomics, with particular emphasis on teamwork and collaboration.