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.

在过去的几十年中，我的实验室研究了绿藻，这是陆地植物的群体。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分别是呼吸和光合作用的部位，但我们也一直在解决研究组中与核基因组（细胞的主要基因组）有关的问题。我们努力的重要主题是记录和解释绿色藻类，有时甚至是土地植物基因组特征的多样性。对于细胞器基因组，这包括完整与碎片，圆形与线性，富含GC的圆形与富含富含gc的变量，紧凑型与肿胀的变量，以及对于核基因组，其非编码DNA的比例是其最近的质体和线粒体起源。我们还估计了绿色植物（藻类和土地植物）的三个基因区室中静音（非编码）位点的相对突变率和核苷酸多样性的水平，并用这些来解释该组成员基因组结构的变化。下一个赠款期间的拟议工作重点介绍了四个主要活动：（1）多甲虫进化枝的更广泛的采样和表征，这是一组无色的绿色藻类，并且失去了光合作用的能力和细胞壁合成的能力，而所有这些重要属的属性都来自欧洲，尽管过去已经描述了北美和南美洲的孤岛，但仍在欧洲属于欧洲。 （2）多甲虫中光合作用的继发性丧失的演变 - 可以通过比较质质体蛋白质组学，其亲密的相对多鼠菌通过比较质质体蛋白质组学来了解基本的光合作用功能； （3）Volvox和Polytomella中线粒体基因组结构的进化； （4）检验突变负担的假设是对所选绿藻类物种中线粒体，叶绿体和核基因组的紧凑度变化的解释。近年来，绿藻吸引了人们的兴趣，因为它们在生物技术方面的潜力，尤其是可再生能源。该小组的基本工作，例如这里提出的，可以提高其在实际应用中的价值。