Unlocking the Mysteries of Plastid Origin Through Comparative Genomic Analysis of Two Paulinella Species

通过两个保利氏菌物种的比较基因组分析解开质体起源之谜

• 批准号: 0827023
• 负责人: Hwan Su Yoon
• 金额: $ 99.39万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0827023&HistoricalAwards=false
• 关键词: Unlocking; Mysteries; Plastid; Origin; Through

The acquisition of photosynthesis by eukaryotes was a pivotal event in evolution because algae and plants form the base of the food chain for life on Earth. Plastids (e.g., chloroplasts), the machines of photosynthesis in algae and plants, have a cyanobacterial origin through primary endosymbiosis, the acquisition of a formerly free-living photosynthetic bacterium. Knowledge of plastid evolution in algae and plants is limited because the primary endosymbiotic event occurred more then a billion years ago. Paulinella chromatophora is a green amoeba that is remarkable because it very recently acquired a plastid via an independent primary endosymbiosis involving a Prochlorococcus or Synechococcus-like cyanobacterium. The closely related Paulinella ovalis lacks a plastid but feeds actively on cyanobacteria. Using these model organisms, this project will 1) sequence genomic DNA and generate a transcriptome database from the photosynthetic amoeba Paulinella chromatophora and sequence genomic DNA from the plastid-lacking Paulinella ovalis using the most modern high-throughput pyrosequencing methods, 2) compare the gene inventories between P. chromatophora and the P. ovalis, and 3) make freely available to the public the Paulinella genome sequences. Genome comparisons between the photoautotrophic P. chromatophora and the heterotrophic P. ovalis will allow the researchers to generate a gene/genome catalogue in two closely related organisms, one with and one without a primary endosymbiotic plastid. This should enable the identification of initial genomic innovations that allowed primary plastid establishment, that is, the critical process that allowed a transition from heterotrophy (animal) to autotrophy (plant). These genomic data could potentially be applied to the field of genetic engineering. This project will support training of undergraduates and post-doctoral research associates from underrepresented groups. The project results will be published in scientific papers and they will be discussed in a genomics workshop. The workshop will draw upon expertise from genome specialists from the US and worldwide and it will include active student participation. The goal of this workshop will be to advance understanding of endosymbiosis and protist genomics.

真核生物获得光合作用是进化中的一个关键事件，因为藻类和植物构成了地球上生命的食物链的基础。作为藻类和植物中的光合作用机器，叶绿体(例如叶绿体)通过初级内生共生作用获得以前自由生活的光合作用细菌，从而起源于蓝藻。由于最初的内生共生事件发生在10亿多年前，因此对藻类和植物中的质体进化的了解是有限的。色泡菌是一种绿色阿米巴，它最近通过与原氯球菌或聚球藻样蓝细菌的独立初级内共生获得了一个质体。与其亲缘关系密切的卵圆泡泡菌缺少一个叶绿体，但以蓝藻为食。利用这些模式生物，本项目将1)利用最先进的高通量焦磷酸测序方法，从光合作用的变形虫基因组DNA中生成转录组数据库，并从缺乏叶绿体的卵形芽孢杆菌基因组DNA中生成转录组数据库，2)比较颜色变形虫和卵形阿米巴的基因清单，3)向公众免费提供泡囊藻基因组序列。通过对光自养和异养卵圆假单胞菌的基因组比较，研究人员可以在两个密切相关的生物中生成基因/基因组目录，一个有内生共生体，另一个没有内生体。这应该能够识别最初的基因组创新，这些创新允许初级叶绿体的建立，也就是允许从异质营养(动物)过渡到自养(植物)的关键过程。这些基因组数据有可能应用于基因工程领域。该项目将支持培训来自代表性不足群体的本科生和博士后研究助理。该项目的成果将发表在科学论文中，并将在基因组学研讨会上进行讨论。研讨会将利用来自美国和世界各地的基因组专家的专业知识，并将有学生积极参与。这次研讨会的目标是促进对内生共生和原生生物基因组学的理解。