Mitochondrial Factors Associated With Pollen Development

一些最有趣的问题正在解决， 高等真核生物涉及基因调控 在特定发展阶段的表达， 亚细胞器之间的通讯。 模型系统 在细胞质雄性不育菜豆中开发的 为解决这些问题提供了理想的遗传材料。 的 该系统具有许多独特的功能。 两个不同的核-mito- 已经确定了导致 花粉表型改变 有证据表明，至少有一些 这种细胞间相互作用的各个方面在发育过程中 监管. 这项研究的重点是线粒体序列， 命名为PVs，与异常花粉发育有关。 的 项目包括开发针对假定的 PV内两个开放阅读框架的产物。 这些抗体 将表征两个预测的线粒体 反应核基因Fr. Fr 导致PVS序列连同 围绕线粒体区域。 第二个核基因Fr 2， 预测改变PV的表达。 Fr和Fr 2均恢复 正常花粉发育。 实验将包括西方 印迹分析，免疫沉淀，原位回交和F2 群体，细胞质雄性不育系，一些 自发的细胞质可育回复突变体和正常对照 线 拟议的研究还将包括表征 线粒体PVS区的转录。 这些实验将描述 一个线粒体序列对两个不同的核 改变花粉发育的基因。 实验还将 确定线粒体内潜在的调节位点 顺序

Some of the most interesting questions being addressed in higher eukaryotic organisms concern the regulation of gene expression at particular stages of development that involve communication between subcellular organelles. The model system that has been developed in cytoplasmic male sterile common bean provides ideal genetic materials to address these questions. The system has a number of unique features. Two distinct nuclear-mito- chondrial genetic interactions have been identified that result in an altered pollen phenotype. Evidence suggests that at least some aspects of this interorganellar interaction are developmentally regulated. The focus of this study is a mitochondrial sequence, designated pvs, associated with abnormal pollen development. The project includes development of antibodies against the putative products of two open reading frames within pvs. These antibodies will characterize the expression of the two predicted mitochondrial products in response to the presence of nuclear gene Fr. Fr results in the elimination of the pvs sequence together with the surrounding mitochondrial region. A second nuclear gene, Fr2, is predicted to alter expression of pvs. Both Fr and Fr2 restore normal pollen development. The experiments will include Western blot analysis, immunoprecipitations, and in situ backcross and F2 populations, the cytoplasmic male sterile line, a number of spontaneous cytoplasmic fertile revertants, and a normal control line. The proposed research will also include characterization of transcription of the mitochondrial pvs region. The experiments will characterize the developmental expression of a mitochondrial sequence in response to two distinct nuclear genes that alter pollen development. The experiments will also identify potential regulatory sites within this mitochondrial sequence.