TRANSFER OF ORGANELLE GENES TO THE NUCLEUS

细胞器基因和基因组的研究对我们理解-- 真核细胞和分子生物学的研究。正常运作 所有真核细胞中细胞器的精确合作 在核遗传系统和细胞器遗传系统之间。这里面的瑕疵 功能对人类健康有直接影响，这从以下几个方面可见一斑 最近关于线粒体遗传病的报道呈爆炸式增长。 这一建议解决了遗传协进化中的根本问题-- 真核细胞离子：细胞器基因是如何发挥作用的 转移到细胞核，这些基因的后果是什么？ 重新安置？ 首先，我们将按顺序探讨几个最近的基因转移案例。 1)深入了解功能激活的时间和过程 细胞核内转移的细胞器基因；2)检查 RNA中间体和逆转录在物理中的流行 细胞间隔之间的序列迁移行为；以及3)测试 剪接体依赖的核前-mRNA内含子进化假说 来自自剪接的第二组内含子。 第二，将叶绿体基因更古老地转移到细胞核 将检验与基因功能有关的两个假说： 1)这种基因转移允许绿藻Coleochaete 跨隔室基因扩增的新情况， 基因拷贝之间的功能差异，以及2)这是相同的 在陆地植物拟南芥中的转移导致了几乎相反的结果 (也是新奇的)情况，即一个核基因同时提供 叶绿体和线粒体具有相同的蛋白质。 最后，我们将继续研究，使用各种分子 进化方法，戏剧性地加速了分子进化 天竺葵叶绿体编码的RNA聚合酶。

The study of organelle genes and genomes is essential to our understand- ing of eukaryotic cellular and molecular biology. The proper functioning of organelles in all eukaryotic cells involves a precise cooperation between nuclear and organelle genetic systems. Defects in this functioning have direct consequences for human health, as is evident from the recent explosion of reports on mitochondrially-inherited diseases. This proposal addresses the fundamental problem in the genetic coevolut- ion of the eukaryotic cell: How are organellar genes functionally transferred to the nucleus and what are the consequences of these genetic relocations? First, several cases of recent gene transfer will be explored in order to 1) gain insights into the timing and process of functional activation of a transferred organellar gene within the nucleus; 2) examine the prevalence of RNA intermediates and reverse transcription in the physical act of sequence migration between cellular compartments; and 3) test the hypothesis that spliceosomal-dependent nuclear pre-MRNA introns evolved from self-splicing group II introns. Second, a more ancient transfer to the nucleus, of the chloroplast gene tufA, will be examined to test two hypotheses relating to gene function: 1) that this gene transfer allowed, in the green alga Coleochaete, a novel situation of cross-compartmental gene amplification, with functional divergence among the gene copies, and 2) that this same transfer, in the land plant Arabidopsis, resulted in the nearly opposite (and also novel) situation, whereby one nuclear gene supplies both the chloroplast and mitochondrion with the same protein. Finally, we will continue to study, using a variety of molecular evolutionary approaches, the dramatically accelerated molecular evolution of the chloroplast-encoded RNA polymerase in geranium.