Collaborative Research: A Multi-Gene Approach to Chlorophytan Phylogeny and Diversity

合作研究：叶绿素系统发育和多样性的多基因方法

• 批准号: 0128952
• 负责人: Marc Anderson
• 金额: --
• 依托单位: North Dakota State University Fargo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-15 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0128952&HistoricalAwards=false
• 关键词: Collaborative; Research; Multi; Gene; Approach

0128952FawleyThree research teams (Buchheim at University of Tulsa, Fawley at North Dakota State University, and Zechman at California State University at Fresno) have begun a collaboration that will address questions about the hierarchical (i.e., phylogenetic) relationships among green algal groups that are collectively known as the Chlorophyta. The Chlorophyta, which has phylum status in the Linnean nomenclatural system, represents one of two branches of the green plant lineage-the other branch being the land plant alliance. The Chlorophyta comprise organisms that range from the microscopic to the macroscopic, exhibit a variety of reproductive strategies (e.g., sexual vs. asexual), and live in a broad spectrum of habitats (e.g., freshwater, saltwater and terrestrial). Some aspects of the current classification scheme for the Chlorophyta, based largely on comparative morphology, have been challenged by new evidence from comparative molecular data. A comprehensive interpretation of the new evidence, however, has not been forthcoming because (1) these new molecular data have not been applied to all groups within the Chlorophyta and (2) in most cases only a single gene has been used to evaluate diversity among select groups of Chlorophyta (unlike the land plants where diversity in some groups has been studied using three or more different genes). The goal of this project is to develop a comprehensive assessment of diversity in the Chlorophyta using a comparative study of DNA sequence data in three different genes, the nuclear 18S ribosomal RNA and 26S ribosomal RNA genes, and the chloroplast rbcL gene. The two rRNA genes code for portions of all ribosomes found in living cells. The rbcL gene is part of the chloroplast genome and codes for a portion of the enzyme responsible for carbon fixation in plants. The Zechman lab at CSU-Fresno will be responsible for gathering data from the chlorophyte group known as the Ulvophyceae. The Fawley lab group at North Dakota State University will be responsible for gathering data from the chlorophyte group known as the Prasinophyceae. The Buchheim lab group at the University of Tulsa will gather data from the two chlorophyte groups, Trebouxiophyceae and Chlorophyceae. The project will culminate in (1) a phylogenetic synthesis of all molecular data for the Chlorophyta, (2) a fundamental re-assessment of chlorophyte classification, integrating morphological and photosynthetic pigment data, and (3) an integration of the chlorophyte molecular phylogenetic data with (published) parallel data from the land plant lineage. Studies using chlorophyte green algae as model organisms (for example, the genus Chlamydomonas, easily cultured in the laboratory) have significantly advanced our understanding of fundamental processes such as photosynthesis and flagellar function. As biologists continue to dissect the molecular and biochemical basis for biological phenomena, new chlorophyte models will be explored in order to understand the spectrum of variation associated with these phenomena. A more comprehensive understanding of the relationships among all chlorophyte groups will be vital to interpreting the results (for example, assessing the broader applicability) from studies of chlorophytes used as model organisms. Moreover, the results from a comprehensive assessment of chlorophyte diversity will inform future studies of biological processes that rely on green algae to model the mechanisms. Lastly, studies of diversity within the Chlorophyta are critical to advancing our understanding of the origins and evolution of the green plant lineage.

0128952Fawleythree研究团队（塔尔萨大学的布赫海姆，北达科他州立大学的法莱，弗雷斯诺州加州州立大学的Zechman）已经开始了一项合作，该合作将解决有关等级制的问题（即，在绿色Algal群体之间的层次（即，系统发育）关系的问题，这些绿色Algal群体是集体所知的Chlorophyta。 在林尼亚命名系统中具有门状态的绿藻是绿色植物谱系的两个分支之一 - 另一个分支是土地工厂联盟。 叶绿体包括从微观到宏观的范围内的生物，表现出各种生殖策略（例如，性与无性恋），生活在广泛的栖息地（例如，淡水，盐水，盐水和地面）。叶绿体当前分类方案的某些方面主要基于比较形态，受到比较分子数据的新证据的挑战。 然而，对新证据的全面解释尚未到来，因为（1）这些新的分子数据尚未应用于氯植物中的所有群体中，（2）在大多数情况下，只有一个基因已使用单个基因来评估精选的氯植物群之间的多样性（与某些组中不同基因的多样性相比，使用三个或更多不同的基因在某些群体中与多样性相比）。 该项目的目的是使用三种不同基因中的DNA序列数据，核18S核糖体RNA和26S核糖体RNA基因和叶绿体RBCL基因的DNA序列数据进行比较研究，对叶绿体中的多样性进行全面评估。 两个rRNA基因代码在活细胞中发现的所有核糖体的一部分。 RBCL基因是叶绿体基因组的一部分，代码为负责植物碳固定的一部分酶。 CSU-Fresno的Zechman实验室将负责从氯植物组收集名为Ulvophyceae的数据。 北达科他州立大学的Fawley Lab Group将负责从称为Prasinophyceae的叶绿素群中收集数据。 塔尔萨大学的Buchheim实验室组将从两个叶绿素群（Trebouxiophyceae和Chlorophyceae）中收集数据。 该项目将最终在（1）叶绿体的所有分子数据的系统发育合成中，（2）对叶绿素分类的基本重新评估，将形态学和光合色素数据整合到（3）将叶绿素分子数据与（出版）linea linea linea的集成。使用叶绿素绿藻类作为模型生物的研究（例如，在实验室容易培养的衣原体属）显着提高了我们对基本过程（例如光合作用和鞭毛功能）的理解。 随着生物学家继续剖析生物学现象的分子和生化基础，将探索新的叶绿素模型，以了解与这些现象相关的变异谱。 对所有叶绿素群之间的关系的更全面的了解对于解释结果（例如，评估更广泛的适用性）至关重要。 此外，对叶绿素多样性的全面评估的结果将为依赖绿色藻类建模机制的生物学过程的未来研究提供信息。 最后，对叶绿体中多样性的研究对于促进我们对绿色植物谱系起源和演变的理解至关重要。