Molecular evolution of green algae

绿藻的分子进化

• 批准号: 9599-2012
• 负责人: Lee, Robert
• 金额: $ 2.4万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=507005
• 关键词: Molecular; evolution; green; algae

Over the past several decades my laboratory has studied green algae, the group from which land plants arose. The main focus of our work is on organelle genomes, i.e., those in mitochondria and chloroplasts, which are the sites of respiration and photosynthesis, respectively, but we have also been addressing questions related to the nuclear genome (the main genome of the cell), in the study group. The overriding theme of our efforts has been to document and explain the diversity of green algal and sometimes land plant genome features. For the organelle genomes this includes variables like intact vs. fragmented, circular vs. linear, GC-rich vs. AT-rich, compact vs. bloated, and for the nuclear genome, the fraction of its non coding DNA that is of recent plastid and mitochondrial origin. We have also estimated the relative mutation rate and the level of nucleotide diversity at silent (non-coding) sites in the three genetic compartments of green plants (algae and land plants) and used these to explain the variations in genome architecture in members of this group. The proposed work for the next grant period focuses on four main activities: (1) Wider sampling and characterization of the Polytomella clade, a group of green algae that is now colorless and has lost the capacity for photosynthesis and for cell wall synthesis-all currently maintained strains of this important genus come from Europe although North and South American isolates have been described in the past; (2) Evolution of the secondary loss of photosynthesis in Polytomella - much can be learned about essential photosynthetic functions in the model alga Chlamydomonas reinhardtii by comparative plastid proteomics with its close relative Polytomella; (3) Evolution of mitochondrial genome structure in Volvox and Polytomella; and (4) testing the mutational-burden hypothesis as an explanation for the compactness variation in mitochondrial, chloroplast, and nuclear genomes in selected green algal species. In recent years, the green algae have attracted interest because of their potential in biotechnology, particularly, renewable energy. Fundamental work on this group such as proposed here can increase their value in practical applications.

在过去的几十年里，我的实验室一直在研究绿藻，陆地植物就是从绿藻中产生的。我们工作的主要重点是细胞器基因组，即线粒体和叶绿体中的细胞器基因组，它们分别是呼吸和光合作用的场所，但我们也一直在解决与核基因组（细胞的主要基因组）相关的问题，在学习小组中。我们努力的首要主题是记录和解释绿藻，有时甚至是陆地植物基因组特征的多样性。对于细胞器基因组，这包括完整与片段、环状与线性、富含 GC 与富含 AT、紧凑与膨胀等变量，对于核基因组，其非编码 DNA 中最近质体的部分和线粒体起源。我们还估计了绿色植物（藻类和陆地植物）三个遗传区室中沉默（非编码）位点的相对突变率和核苷酸多样性水平，并用这些来解释该植物成员的基因组结构的变化。团体。下一个资助期的拟议工作重点关注四项主要活动：（1）对 Polytomella 分支进行更广泛的采样和表征，这是一组绿藻，现在是无色的，并且已经失去了光合作用和细胞壁合成的能力 - 目前所有这些都是尽管过去曾描述过北美和南美的分离株，但这一重要属的维持菌株来自欧洲； (2) Polytomella 光合作用继发性丧失的进化——通过与其近亲 Polytomella 比较质体蛋白质组学，可以了解模型藻类莱茵衣藻 (Chlamydomonas Reinhardtii) 的基本光合作用功能； (3) 团藻和多胞藻线粒体基因组结构的进化； (4) 测试突变负担假说，以解释选定绿藻物种中线粒体、叶绿体和核基因组的致密性变化。近年来，绿藻因其在生物技术，特别是可再生能源方面的潜力而引起了人们的兴趣。此处提出的有关该组的基础工作可以增加其在实际应用中的价值。