Mitochondrial Sorting and Inheritance in Arabidopsis

多细胞真核生物的细胞质是一个令人惊讶的动态实体，具有复杂的细胞器间回路，影响细胞功能、代谢和程序性死亡的几乎所有方面。这种复杂性，加上强大的模型系统研究的缺乏，阻碍了理解线粒体行为的潜在机制的进展。本项目重点研究拟南芥线粒体基因组维护、分类和遗传的核方向。我们已经确定了这些过程的几个假定组成部分，我们打算研究它们的功能和调控。核心假设是线粒体分选和遗传行为源于核编码线粒体DNA维持和传递位点的表观遗传和配子特异性调节。我们将利用突变和转基因分析来研究可能参与DNA复制、分选、重组和遗传过程的8个位点的功能。我们将利用异位表达和原位杂交方法，以及结合增强子和基因陷阱资源的遗传方法来研究拟南芥中它们的调控。作为这项工作的结果，我们期望确定所选择的基因座在线粒体基因组维持中的功能，并表征它们在生殖发育过程中的调节性质。这一信息对我们了解高等真核生物的核-胞质相互作用具有重要意义。从这项研究中获得的数据将影响我们对印迹和基因调控过程的理解，这些过程可能对成功的体外受精技术至关重要。此外，我们的项目还参与了内布拉斯加州青年科学家培训项目，通过提供有趣且技术多样化的项目形式的暑期实习经验，增加招募优秀少数民族和贫困高中生进入生命科学领域的机会。

The cytoplasm of a multicellular eukaryote is a surprisingly dynamic entity with complex inter-organellar circuitries that influence nearly all aspects of cellular function, metabolism and programmed death. This complexity, together with a paucity of powerful model systems for study, has hindered progress in understanding the underlying mechanics of mitochondrial behavior. Our focus in this project is on the nuclear direction of mitochondrial genome maintenance, sorting and inheritance in Arabidopsis. We have identified several putative components of these processes, and we intend to study their function and regulation. The central hypothesis is that mitochondrial sorting and inheritance behavior derives from epigenetic and gamete-specific regulation of nuclear-encoded mitochondrial DNA maintenance and transmission loci. We will investigate the function of eight loci likely involved in DNA replication, sorting, recombination and inheritance processes using mutation and transgenic analysis. We will investigate their regulation using ectopic expression and in situ hybridization approaches, complemented with genetic approaches that incorporate enhancer and gene trap resources in Arabidopsis. As an outcome of this work we expect to determine the function of the selected loci in mitochondrial genome maintenance, and to characterize the nature of their regulation during reproductive development. This information is of fundamental importance to our understanding of nuclear-cytoplasmic interactions in higher eukaryotes. Data derived from this study would impact our understanding of imprinting and gene regulatory processes likely essential to successful in vitro fertilization technologies. Moreover, our project participates in the Young Nebraska Scientist training effort to enhance opportunities to recruit outstanding minority and underprivileged high school students to the life sciences by providing summer internship experiences in interesting and technically diverse project formats.