Analysis of the plant retrotransposon Tto1 and its use for genetic manipulation

植物逆转录转座子Tto1的分析及其在遗传操作中的应用

• 批准号: 22218002
• 负责人: Professor Dr. Andreas Bachmair
• 金额: --
• 依托单位: Max F. Perutz Laboratories
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/22218002?language=en
• 关键词: Analysis; plant; retrotransposon; Tto1; its

Retroelements are pieces of DMA that can multiply more often than the host genome. To that end, the element-encoded enzyme reverse transcriptase uses retroelement RNA as a template to generate a DNA copy, which is inserted into the genome by another element-encoded protein, integrase. This process of retrotransposition is usually restricted to stressful conditions. Retroelements can make up more than half of the DNA content of animal and plant cells, but most of these elements are nonfunctional due to point mutations, deletions or insertions. We use biochemical and genetic methods to analyze a transpositioncompetent plant retrotransposon, Tto1. Our previous studies showed that current (textbook) knowledge of retroelement multiplication is surprisingly inadequate to understand transposition of Tto1. In addition to a more profound understanding of the retrotransposition process, our studies are directed towards application of this knowledge. Controlled (inducible) transposition in absence of the natural inducer, tissue culture stress, would turn Tto1 into a powerful tool for insertional mutagenesis, because Tto1 inserts preferentially into coding regions. Such a system would be particularly useful for plants with large genomes, where techniques such as positional cloning are not established or are too cumbersome.

逆转录因子是可以比宿主基因组更频繁地繁殖的DMA片段。为此，元件编码的酶逆转录酶使用逆转录元件RNA作为模板来产生DNA副本，该副本由另一种元件编码的蛋白质整合酶插入基因组。这种反转位过程通常局限于压力条件下。逆转录因子占动物和植物细胞DNA含量的一半以上，但由于点突变、缺失或插入，大多数逆转录因子无功能。我们利用生物化学和遗传学方法分析了植物转座子tt1。我们之前的研究表明，目前（教科书）关于逆元素乘法的知识令人惊讶地不足以理解Tto1的转位。除了对逆行转位过程有更深刻的理解外，我们的研究是针对这些知识的应用。在没有自然诱导剂（组织培养胁迫）的情况下，控制（可诱导）转位将使tt1成为插入诱变的有力工具，因为tt1优先插入编码区。这样的系统对于具有大基因组的植物特别有用，在这些植物中，位置克隆等技术还没有建立起来，或者过于繁琐。