TRANSFER OF ORGANELLE GENES TO THE NUCLEUS

细胞器基因和基因组的研究对于我们的理解至关重要- 真核细胞和分子生物学。 正常运作 所有真核细胞中的细胞器都涉及精确的合作 核遗传系统和细胞器遗传系统之间。 这方面的缺陷 功能对人类健康有直接影响，这一点可以从 最近有关线粒体遗传性疾病的报告激增。 该提议解决了遗传协同进化的基本问题 真核细胞的离子：细胞器基因如何发挥功能 转移到细胞核中，这些遗传的后果是什么 搬迁？ 首先，将探讨最近基因转移的几个案例，以便 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普遍性 细胞区室之间的序列迁移行为； 3）测试 剪接体依赖性核前 mRNA 内含子进化的假设 来自第二组内含子的自剪接。 其次，更古老的叶绿体基因向细胞核的转移 tufA 将被检查以测试与基因功能相关的两个假设： 1）这种基因转移使得在绿藻鞘毛纲中， 跨区室基因扩增的新情况 基因拷贝之间的功能差异，2）这相同 陆地植物拟南芥中的转移导致了几乎相反的结果 （也是新颖的）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，利用多种分子 进化方法，急剧加速的分子进化 天竺葵中叶绿体编码的RNA聚合酶的研究。

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.