GENETIC ANALYSIS OF BACTERIAL PHOTOSYNTHESIS

该项目的长期目标是识别和绘制 在遗传和物理上，这些遗传因素和区域， 参与的合成，结构/功能，和调节 诱导性细胞内膜系统 光合异养菌，球形红细菌。这种分子遗传学 方法，再加上详细的生物化学分析膜 结构和功能将有助于更好地了解 膜合成和调节的遗传基础。 的重要性 生物膜对正常细胞活动的影响最能反映在 肿瘤状态下这种膜的改变，或 肌强直中改变的膜的性质，或 在家族性葡萄糖-半乳糖吸收不良中肠己糖转运， 这里仅举几例。 作为额外的长期目标，我们建议 研究：无氧光合作用的起源， 二倍体状态和线粒体系的进化 发展 这些长期目标将得到具体处理 通过分离、鉴定、补充和绘制 直接参与细胞内膜合成的基因， 监管，特别强调针对早期步骤， 卟啉环的生物合成以及开发独特的 用于分离新突变体的富集/选择条件 膜合成和/或调节缺陷的菌株。 因为 高含量的鸟嘌呤和胞嘧啶（70%）。类球孢菌属 需要注意这些基因的表达， 元素以及遗传或假遗传系统的发展 这将有助于对这些复杂过程进行详细分析。 此外，还发现了两条不同的染色体。sphaeroides 代表许多遗传基因座，一种部分二倍体状态， 代表了一个独特的机会来研究 在这个非常原始的实验系统中分离的连锁群。 在 特别是，每个链接的物理结构的维护 连锁群的遗传稳定性及各连锁群间的互作关系 在基因表达水平上， 更复杂系统的起源。 我们的能力，雇用一个相对 简单的遗传系统作为一个工具，以更好地了解更复杂的 同源和非同源染色体之间的相互作用 可以更全面地了解真核生物的二倍体状态， 系统.

The long-tern objectives for this project are to identify, and map both genetically and physically, those genetic elements and regions which are involved in the synthesis, structure/function, and regulation of the inducible intracellular membrane system in teh faculative photoheterotroph, Rhodobacter sphaeroids. This molecular genetic approach, coupled with a detailed biochemical analysis of membrane structure and function will lead to a better understanding of the genetic basis for membrane synthesis and regulation. The importance of biological membranes to normal cellular activities is best reflected in the alterations of such membranes in the neoplastic state, or the properties of altered membranes in myotonia, or the alteration in intestinal hexose transport in familial glucose-galactose malabsorption, to mention a few. As additional long-term objectives, we propose to examine: the origins of anoxygenic photosynthesis, the development of the diploid state and the evolution of the mitochondrial line of development. These long-term objectives will be specifically addressed through the isolation, identification, complementation and mapping of genes directly involved in intracellular membrane synthesis and regulation with special emphasis directed towards the early steps in porphyrin ring biosynthesis as well as the development of unique enrichment/selection conditions for the isolation of novel mutant strains defective in membrane synthesis and/or regulation. Because of high quanine plus cytosine content (70%) of R. sphaeroides particular attention needs to be directed to the expression of these genetic elements as well as the development of genetic or pseudogenetic systems which will facilitate a detailed analysis of these complex processes. In addition, the presence of two distinct chromosomes in R. sphaeroides representing for a number of genetic loci, a merodiploid state, represents a unique opportunity to investigate the interaction between separate linkage groups in this very primitive experimental system. In particular, the maintenance of the physical structure of each linkage group, its genetic stability and the interaction of each linkage group at the level of gene expression shoul further our understanding of the origins of more complex systems. Our ability to employ a relatively simple genetic system as a tool to better understand the more complex interactions between homologous as well as non-homologous chromosomes can lead to a fuller understanding of the diploid state in eukaryotic systems.