Regulation of Mu activity in maize

在玉米中发现的转座因子Mu在几个方面是独一无二的。该元素最初是由该实验室克隆的，但随后几个实验室的研究表明，所有克隆的Mu元素都是不完美的，因为它们本身不能诱导转位。1991年，这个实验室和另外两个实验室终于克隆出了“主”元素并确定了其特征，拟议的工作是这些研究的继续。当处于活跃染色体位置时，该元件编码两条信息。染色体位置和性传播方式的差异会影响MuR1转位率。我们还表明，该元件可以并且将自动，我们将使用这些自动突变体以及其他更传统的衍生突变体来描述两种转录本及其蛋白质的转位机制和功能。一个长期的目标将是尝试利用这种元素转座子标记对世界营养如此重要的谷类作物。转座子或“跳跃基因”已被证明在理解基本遗传机制方面具有智力上的兴趣，并且具有实际意义，因为它们可以被改造成基因载体。这两个利益是最好的服务于完整的表征和理解这些DNA序列的特征。Mu的表征是非常重要的，因为它已经被发现具有在迄今表征的数百个转座元素中独一无二的性质。在大麦中检测到这种元素的片段带来了长远的希望，即基因工程可能为改善全世界的谷类作物提供一种极其重要的工具。

The transposable element, Mu, found in maize is unique in several ways. The element was first cloned by this laboratory, but subsequent studies by several laboratories demonstrated that all of the cloned elements identified as Mu were imperfect in that they could not in themselves induce transposition. The "master" element was finally cloned and characterized by this laboratory, as well as two other laboratories in 1991, and the proposed work is a continuation of those studies. The element encodes two messages when in an active chromosomal position. Differences in chromosomal position and mode of sexual transmission can effect the rate of MuR1 transposition. We have also shown that the element can and will automutate, and we will use these automutants along with other more conventionally derived mutants to describe the mechanism of transposition and functions of the two transcripts and their proteins. A long term goal will be to attempt to utilize this element to transposon tag cereal crops that are so important to world nutrition. %%% Transposons, or "jumping genes" have proven to be of intellectual interest in understanding fundamental genetic mechanisms and of practical importance, in that they can be engineered as gene vectors. Both of those interests are best served in the complete characterization and understanding of the characteristics of such DNA sequences. Mu is extremely important to characterize in that it has already been found to have properties which are unique among the hundreds of transposable elements so far characterized. The detection of the fragments of the element in barley offers the long-range hope that genetic engineering might provide an extremely important tool for improving cereal crops throughout the world.