PLANT INTRON PROCESSING

虽然它可能是合乎逻辑的假设，在某些分子 所有低级和高等真核生物都有一个共同的机制 前信使核糖核酸剪接，体内和体外的多种基因转移 实验表明，两者之间存在着关键的差异 哺乳动物、酵母和植物的RNA加工事件。这些 差异，这可能是由于序列中的差异造成的 由内含子剪接组件识别，延伸到单子叶和 Dicot组的植物和已经在体内有效防止 含内含子的单子叶植物基因在水稻中的表达 双子叶植物。尽管这些加工缺陷 存在，尚未启动内含子处理研究 确定单子叶植物和双子叶植物的关键差异 阻止有效切除单子叶内含子的mRNA Dicot核。这里提出的实验的目的是 确定切除过程中形成的RNA加工中间体 植物内含子和确定根本差异 单子叶和双子叶RNA处理信号之间的差异 植物基因在异源核中的表达。 具体地说，本提案中描述的研究旨在 更清楚地定义决定分子参数的分子参数 植物细胞中RNA加工的准确性和效率。这个 该项目的具体目标是：(1)确定和 鉴定双核苷酸前-mRNAs中的核苷酸序列， 中的内含子需要准确而有效的切除 Dicot细胞核；(2)鉴定小核糖核酸和蛋白质组分 负责内含子切除的Dicot核提取物：(3)至 评估防止有效的核苷酸序列 双子叶核中单子叶内含子的切除：(4)发育 单子叶RNA加工提取物，可用于评估 单子叶和双子叶前体的内含子加工效率 成绩单。

Although it might he logical to assume that, at some molecular level all lower and higher eukaryotes share a common mechanism for pre-mRNA splicing, a variety of in vivo and in vitro gene transfer experiments indicate that critical differences exist between the mammalian, yeast and plant RNA processing events. These differences, which may result from variations in the sequences recognized by intron splicing components, extend to the monocot and dicot groups of plants and have prevented the efficient in vivo expression of monocotyledonous genes containing introns in dicotyledonous plants. Although these processing deficiencies exist, no intron processing studies have been initiated to determine the critical differences between monocot and dicot pre- mRNAs which prevent the efficient excision of monocot introns in dicot nuclei. The experiments proposed herein are aimed at determining the RNA processing intermediates formed during excision of plant introns and at determining the fundamental differences between monocot and dicot RNA processing signals which block the expression of plant genes in heterologous nuclei. Specifically the research described in this proposal is aimed at more clearly defining the molecular parameters that determine the accuracy and efficiency of RNA processing in plant cells. The detailed objectives of this project are: (1) To identify and characterize the nucleotide sequences within dicot pre-mRNAs that are required for accurate and efficient excision of introns in dicot nuclei; (2) to identify the snRNA and protein components of dicot nuclear extracts responsible for intron excision: (3) to evaluate the nucleotide sequences which prevent the efficient excision of monocot introns in dicot nuclei: (4) to develop monocot RNA processing extracts which can be used to evaluate the intron processing efficiency of monocot and dicot precursor transcripts.