Genetics of Maize Mitochondria

线粒体突变的分析在以下方面提供了信息： 几种生物，包括酵母菌、真菌和人类。 遗传 植物线粒体基因组的分析一直受到限制， 事实上，只有少数已知祖先的突变被发现， 介绍了 我们集中研究了一系列致命的玉米突变 （非染色体条纹; NCS）在异质性植物中存活。 不同的NCS突变体与不同的表型相关， 这些突变已被证明是缺失， 表达至少三种不同的线粒体基因（COX 2， nad 4和共转录的S3和L16核糖体蛋白基因。 该提案的主要目标是通过以下方式阐明机制： NCS损伤导致基因表达改变。 我们将 分析NCS 2和NCS 3植物中的突变和正常转录物 并产生抗体来确定转录本 受NCS突变影响的基因在非突变植物中翻译 线粒体 本项目的长期目标是了解 植物线粒体基因对细胞器的影响 生物发生和整体细胞功能。 拟议的研究 应该澄清转录和转录后的方面， 植物线粒体中的调节。 本提案的第二个目标 是试图开发一个系统来展示玉米 使用NCS 6突变体进行线粒体转化，NCS 6突变体携带 部分缺失了特征明确的cox 2基因。 的 转换系统的可用性应有助于研究 植物线粒体中的假定调节序列。 //

The analysis of mitochondrial mutations has been informative in several organisms, including yeast, fungi and humans. The genetic analysis of plant mitochondrial genomes has been limited due to the fact that only a few mutations with known progenitors have been described. We have focused on a set of lethal maize mutations (Nonchromosomal stripe; NCS) that survive in heteroplasmic plants. Different NCS mutants are associated with distinct phenotypes and the mutations have been shown to be deletions affecting the expression of a least three different mitochondrial genes (cox2, nad4 and the co-transcribed S3 and L16 ribosomal protein genes.) The major goal of this proposal is to elucidate the mechanisms by which the NCS lesions cause altered gene expression. We will analyze the mutant and normal transcripts in NCS2 and NCS3 plants and generate antibodies to determine whether the transcripts affected by NCS mutations are translated within nonmutant plant mitochondria. The long-term objective of this project is to understand the effects of individual plant mitochondrial genes on organelle biogenesis and overall cellular function. The proposed studies should clarify aspects of transcriptional and post-transcriptional regulation in plant mitochondria. A second goal of this proposal is to attempt to develop a system for demonstrating maize mitochondrial transformation using the NCS6 mutant, which carries a partial deletion of the well-characterized cox2 gene. The availability of a transformation system should facilitate studies of putative regulatory sequences in plant mitochondria.*** //