Regulation of Mu Activity in Maize

玉米 Mu 活性的调节

• 批准号: 9603119
• 负责人: Michael Freeling
• 金额: $ 10万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9603119&HistoricalAwards=false
• 关键词: Regulation; Mu; Activity; Maize

9603119 Freeling Technical section A typical Mutator (Mu) line of maize carries about 100 Mu transposons and about five autonomous Mu transposons called MuDR. A minimal line that carries a single MuDR has been characterized. All phenotypes induced by transposition, excision, demethylation, and suppression of Mu-induced alleles, are specified by this element. Deletion analysis of MuDR-1 will be continued in order to ascribe specific functions to regions of MuDR DNA structure and domains of the encoded proteins A and B. Antibody to A will be prepared and with the already available antibody to B, immunolocalization and nuclear protein coprecipitation experiments will be done. The mechanism of Mu suppression will be studied using a quantitative assay, and reverse genetics will be used to target small deletions to particular regions of MuDR-1 (p1). The observed phenomenon whereby Mu becomes less active during development and following inbreeding even though intact MuDR elements exist in the genome called "dominant negative regulation", will be investigated. Promoter diversity will be studied using a Mu excision event which resulted in a series of mis-repair events affecting a region of about 400 bp. A single MuDR element has been introduced into oat via a sexual cross and its behavior in a non-native species of grass will be analyzed. Non-technical abstract A transposable element native to corn, Mu, will be studied. A strain which contains only one master element, in contrast to the many usually present in the corn genome, will be used to study the structure and the function of the element. A phenomenon, dominant negative regulation, which results in a cession of activity by the Mu element during development and following inbreeding even though many structurally intact elements are present in the genome, will be investigated. The availability of this strain and its progeny also makes it possible to study the effects of variation in promoter sequence and the behavior of the transposon when it is transferred to a foreign host.

9603119 Freeling 技术部分 典型的突变 (Mu) 玉米品系携带约 100 个 Mu 转座子和约 5 个称为 MuDR 的自主 Mu 转座子。携带单个 MuDR 的最小线已经被表征。由转座、切除、去甲基化和 Mu 诱导的等位基因抑制诱导的所有表型均由该元素指定。将继续对 MuDR-1 进行删除分析，以便将特定功能归因于 MuDR DNA 结构区域以及编码蛋白 A 和 B 的结构域。将制备 A 抗体，并利用现有的 B 抗体，进行免疫定位和核蛋白共沉淀实验。将使用定量分析来研究 Mu 抑制机制，并使用反向遗传学将小缺失靶向 MuDR-1 (p1) 的特定区域。尽管基因组中存在完整的 MuDR 元件，但所观察到的 Mu 在发育过程中和近亲繁殖后变得不那么活跃的现象（称为“显性负调控”）将得到研究。将使用 Mu 切除事件来研究启动子多样性，该事件导致影响约 400 bp 区域的一系列错误修复事件。单一 MuDR 元件已通过有性杂交引入燕麦中，并将分析其在非本地草种中的行为。 非技术摘要 将研究玉米原生的转座元件 Mu。与玉米基因组中通常存在的许多主元件相比，仅包含一个主元件的菌株将用于研究该元件的结构和功能。将研究显性负调控现象，该现象会导致 Mu 元件在发育过程中和近交后失去活性，即使基因组中存在许多结构完整的元件。该菌株及其后代的可用性还使得研究启动子序列变异的影响以及转座子转移到外来宿主时的行为成为可能。