Epigenetic Variation in the Arabidopsis Genome

拟南芥基因组的表观遗传变异

• 批准号: 0956820
• 负责人: Eric Richards
• 金额: $ 12.54万
• 依托单位: Boyce Thompson Institute Plant Research
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0956820&HistoricalAwards=false
• 关键词: Epigenetic; Variation; Arabidopsis; Genome

Epigenetic information, in the form of differential cytosine methylation and alternative chromatin structures, plays a central role in the modulation of eukaryotic gene expression. In some cases, alternative epigenetic modifications can be inherited through meiosis, opening up the possibility that epigenetic variation plays a role in generating phenotypic and genomic diversity. This project is an investigation of two examples of epigenetic variation in the flowering plant Arabidopsis thaliana. The first epigenetic system to be investigated involves the complex BAL genomic locus, which contains paralogous pathogen defense genes and interspersed transposable elements. The defective bal epigenetic allele leads to overexpression of several genes from the locus and confers both developmental and pathogen defense phenotypes. The research will probe the molecular changes at the locus that cause this mis-regulation of gene expression, as well as the unusual metastable behavior of the bal allele. The second objective of the project is to characterize a newly discovered class of non-LTR retrotransposons, comprised of members that are epigenetically silenced in some strains of Arabidopsis but not others. The mechanistic basis and significance of this natural epigenetic variation will be investigated.The slightly different forms of individual organisms in a population result from the interaction between the genetic potential of those individuals and the environment. Also important are epigenetic changes, which do not involve alterations in DNA sequence but rather the packaging of this genetic information. This project takes advantage of the experimental tools available in the small flowering plant Arabidopsis to study the role of epigenetic changes in inheritance and the control of morphological diversity among individuals and strains.

表观遗传信息以差异胞嘧啶甲基化和替代染色质结构的形式在真核基因表达的调节中起着核心作用。 在某些情况下，可以通过减数分裂遗传替代表观遗传修饰，这使表观遗传变异在产生表型和基因组多样性中起作用。 该项目是对开花植物拟南芥表观遗传变异的两个例子的研究。 要研究的第一个表观遗传学系统涉及复杂的BAL基因组基因座，其中包含寄生虫病原体防御基因和散布的转座元素。 有缺陷的BAL表观遗传等位基因导致基因座的几种基因过表达，并赋予发育和病原体防御表型。 这项研究将探测该基因座的分子变化，从而导致基因表达的错误调节，以及BAL等位基因的异常亚稳态行为。 该项目的第二个目标是表征新发现的非LTR逆转录座子，由成员组成，这些成员在某些拟南芥中表观遗传沉默，但不是其他菌株。 将研究这种自然表观遗传变异的机械基础和意义。人群中各种生物的略有不同形式是由于这些人与环境的遗传潜力之间的相互作用而导致的。 同样重要的是表观遗传变化，这不涉及DNA序列的改变，而是该遗传信息的包装。 该项目利用了小型开花植物拟南芥中可用的实验工具来研究遗传变化在遗传中的作用以及对个体和菌株之间形态多样性的控制。