MOLECULAR SYSTEMATICS AND EVOLUTION OF GENUS CAULERPA

Caulerpa 属的分子系统学和进化

• 批准号: 6478881
• 负责人: FREDERICK W ZECHMAN
• 金额: $ 3.22万
• 依托单位: CALIFORNIA STATE UNIVERSITY FRESNO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2002-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6478881
• 关键词: Chlorophyta; aquatic organism; biochemical evolution; gene expression; genetic polymorphism; nucleic acid sequence; plant ecology; plant genetics; plant morphology; plant population genetics; polymerase chain reaction; ribosomal DNA; species difference; systematic biology

Support is requested for a molecular systematic investigation of the genus Caulerpa, a pantropical genus with ecological and biomedical importance. The specific objectives of the proposed study are to: 1) establish a robust molecular phylogeny of the Caulerpa based on four independent molecular data sets: nuclear ribosomal ITS sequences, 26S ribosomal DNA, and chloroplast encoded rbcL and psbA genes; 2) identify monophyletic groups for comparison with the current taxonomy of the genus, and characterization of morphological and biochemical evolution, 3) compare the pattern and rate of molecular evolution for different species, and 4) determine whether the inferred phylogenetic hypotheses are consistent with a presumed Indo-West Pacific origin of these algae, and if phylogenetic patterns of Caulerpa are correlated with the patterns of togther tropical marine organisms that may have shared a common marine biogeographic history. The large unicellular plants of Caulerpa are examples of single cells with a complex internal and external morphology with differentiated functions. Representatives of this genus have been recently implicated as a threat to biodiversity in the Mediterranean Sea and as the subject of toxicological studies on the secondary metabolite, caulerpenyne. A phylogenetic perspective of these algae will provide insights into the evolution and characterization of these features. Although phylogenetic and marine biogeographic hypothesis have been proposed for these algae, they have not been tested in the context of broad sampling of taxa with DNA sequence data. The focus of the project will include an evaluation of the evolution of morphological, ultrastructural and biochemical features, and elucidation of the rates and patterns of molecular variation at the with marine biogeographic hypotheses, (e.g., Tethyan vicariance models) to assess the historical causes of present day distribution. The PI has over fifteen years experience working with temperate and tropical marine algal taxonomy and ecology and another ten years working on the molecular systematics of tropical marine green algae. Successful completion of this project will increase our understanding of marine algal phylogeny, historical biogeography, and the rates of patterns of molecular evolution in marine organisms.

请求支持对具有生态和生物医学重要性的泛热带属Caulerpa属进行分子系统研究。拟议研究的具体目标是：1)基于四个独立的分子数据集：核糖体ITS序列、26S核糖体DNA以及编码rbcL和PSBA基因的叶绿体基因，建立Caulerpa的强大分子系统发育；2)确定单系群，用于与该属当前的分类比较，并描述形态和生化进化的特征；3)比较不同物种的分子进化模式和速度；4)确定推断的系统发育假说是否与这些藻类起源于印度-西太平洋的假设一致，以及Caulerpa的系统发育模式是否与其他可能具有共同海洋生物地理历史的热带海洋生物的模式相关联。木兰属大型单细胞植物是单细胞的例子，具有复杂的内部和外部形态，具有不同的功能。这一属的代表最近被认为是对地中海生物多样性的威胁，并被作为次生代谢物--木勒烯的毒理学研究的对象。这些藻类的系统发育观点将为这些特征的进化和特征提供洞察力。尽管已经提出了关于这些藻类的系统发育和海洋生物地理假说，但它们还没有在用DNA序列数据对分类群进行广泛采样的背景下进行检验。该项目的重点将包括对形态、超微结构和生化特征的演变进行评价，并阐明该区域的分子变异率和模式，以符合海洋生物地理假说(例如特提斯替代模型)，以评估当今分布的历史原因。该研究所在温带和热带海洋藻类分类和生态学方面有超过15年的工作经验，在热带海洋绿藻的分子系统学方面也有10年的工作经验。这个项目的成功完成将增加我们对海藻系统发育、历史生物地理学和海洋生物分子进化模式的速率的了解。