U.S.-Austria Cooperative Research: A Model for Plastid Evolution--Cyanophora Cyanelle DNA (Molecular Biology)

该奖项将支持亚利桑那大学生物化学系Hans J. Bohnert教授和奥地利维也纳大学普通生物化学研究所Wolfgang Loeffelhardt博士之间为期两年的合作研究项目。科学家和他们的研究小组成员将研究来自悖论藻的小藻DNA的基因组和基因结构。他们将试图确定(1)在青叶和高等植物叶绿体DNA中组织不同的几个基因/操纵子的结构；(2)青叶依赖于从周围细胞质进口蛋白质的程度，以及这种运输是如何实现的，与高等植物的运输不同或相同。这项工作的长期目标是通过监测已被充分研究的高等植物叶绿体特征和小微细胞基因组之间的差异，哪些进化选择是可用的，以允许光合活性细胞器被整合到一个真核细胞的代谢。悖论藻中的小单体是质体的一个例子，是植物细胞的一种被膜包围的成分。叶片中的叶绿体是另一个更为人所知的例子。在这项研究中，合作科学家将开展生化和分子生物学研究，旨在证明蓝藻基因与高等植物叶绿体中的基因和蓝藻基因的亲缘程度。这项工作包括对几个小单体染色体区域进行测序，这些区域是为了进行这些比较而选择的预期价值。这样就有可能收集到从简单细菌到似蓝藻再到高等植物（如树木）的特定基因进化的证据。博纳特教授在分子生物学和植物遗传学方面经验丰富。Loeffelhardt教授是一位生物化学家，在处理这些实验中要研究的蛋白质方面有经验。他们的专业知识将在一项研究中结合起来，该研究有望阐明位于生物体中不同细胞区室的基因的进化，这些基因的进化历史尚不清楚。

This award will support a two-year cooperative research project between Professor Hans J. Bohnert, Department of Biochemistry, University of Arizona, and Dr. Wolfgang Loeffelhardt, Institute for General Biochemistry, University of Vienna, Austria. The scientists and members of their research groups will study the genome and gene structure of cyanelle DNA from Cyanophora paradoxa. They will attempt to determine (1) the structure of several genes/operons on cyanelle DNA which are differently organized in cyanelle and higher plant chloroplast DNA and (2) the extent to which the cyanelle is dependent on import of proteins from the surrounding cytoplasm and how this transport is achieved, either differently from or identically to the transport in higher plants. The long-term goal of the work is to understand, by monitoring differences between the well-studied higher plant chloroplast characteristics and the cyanelle genome, which evolutionary options were available to permit a photosynthetically active organelle to be integrated into the metabolism of a eukaryotic cell. The cyanelle in Cyanophora paradoxa is an example of a plastid, a membrane-enclosed component of a plant cell. Chloroplasts in leaves are another, better-known example. In this study, the cooperating scientists will carry out biochemical and molecular biological studies aimed at demonstrating the degree of relatedness of cyanelle genes to those in higher plant chloroplasts and to cyanobacterial genes. The work involves sequencing several cyanelle chromosome regions selected for their anticipated value in making these comparisons. In this way it may be possible to gather evidence for the evolution of specific genes from simple bacteria through Cyanophora paradoxa to still higher plants, such as trees. Professor Bohnert is experienced in molecular biology and plant genetics. Professor Loeffelhardt is a biochemist with experience in working with the proteins to be studied in these experiments. Their expertise will be combined in a study which is expected to shed light on the evolution of genes that are located in different cellular compartments in an organism whose evolutionary history is not well understood.