Genomics and proteomics of nucleomorph-containing algae

含核藻类的基因组学和蛋白质组学

• 批准号: 283335-2009
• 负责人: Archibald, John
• 金额: $ 2.48万
• 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: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=525678
• 关键词: Genomics; proteomics; nucleomorph; containing; algae

The Archibald Laboratory uses molecular biological and computational methods to study the genes and genomes of eukaryotic (nucleus-containing) organisms. Our work focuses on the cryptophytes and chlorarachniophytes, two highly unusual groups of algae that acquired photosynthesis through a process called 'secondary endosymbiosis'. This occurs when a phagotrophic (cell-eating) eukaryote engulfs a photosynthetic eukaryote and retains its light-harvesting apparatus (plastid), and has given rise to some of the most ecologically significant phototrophs on the planet. In most secondary plastid-containing algae, (e.g., diatoms and kelp), the nucleus of the secondary endosymbiont has completely disappeared, having transferred all essential genes to the nuclear genome of the host cell. However, in cryptophytes and chlorarachniophytes, the endosymbiont nucleus persists in a miniaturized form called a 'nucleomorph', and the endosymbiont-derived cytoplasm (the 'periplasmic space') is retained as the site of essential cellular processes such as DNA replication, transcription and translation. As the coding capacity of nucleomorph genomes is extremely limited, most of the proteins functioning in the periplastid space must be host nucleus-encoded, but the diversity of cellular processes taking place in this unusual cellular compartment are currently unknown. Using a battery of molecular, biochemical and comparative genomic techniques, we will analyze the plastid, periplastid and nucleomorph proteomes of cryptophyte and chlorarachniophyte algae in order to (1) elucidate their true biochemical complexity and (2) understand the extent to which host- and endosymbiont-derived proteins have contributed to the molecular machines now functioning in both the host and endosymbiont cytoplasmic compartments. This research will provide insight into the minimal molecular machinery required to sustain core eukaryotic cellular processes and, more generally, shed light on an endosymbiotic process that has given rise to countless species of secondary plastid-containing algae on Earth.

阿奇博尔德实验室使用分子生物学和计算方法来研究真核（含核）生物体的基因和基因组。我们的工作重点是隐藻类和氯蛛藻类，这是两种非常不寻常的藻类，它们通过称为“次级内共生”的过程获得光合作用。当吞噬性（吃细胞）真核生物吞噬光合真核生物并保留其光捕获装置（质体）时，就会发生这种情况，并产生了地球上一些生态上最重要的光养生物。在大多数含有次生质体的藻类（例如硅藻和海带）中，次生内共生体的细胞核已完全消失，所有必需基因已转移至宿主细胞的核基因组中。然而，在隐植物和绿蛛植物中，内共生体核以称为“核形态”的小型化形式持续存在，并且内共生体衍生的细胞质（“周质空间”）被保留为重要细胞过程（例如DNA复制、转录和翻译）的场所。由于核型基因组的编码能力极其有限，大多数在周质体空间中起作用的蛋白质必须是宿主核编码的，但在这个不寻常的细胞区室中发生的细胞过程的多样性目前尚不清楚。使用一系列分子、生化和比较基因组技术，我们将分析隐植物和氯蛛藻的质体、周质体和核形态蛋白质组，以便（1）阐明它们真正的生化复杂性，以及（2）了解宿主和内共生体衍生的蛋白质对目前功能的分子机器的贡献程度 在宿主和内共生体细胞质区室中。这项研究将深入了解维持核心真核细胞过程所需的最小分子机制，更广泛地说，将揭示内共生过程，该过程在地球上产生了无数次生质体藻类物种。