Collaborative Research: Evolution of acquired phototrophy by organelle sequestration in Mesodinium ciliates

合作研究：中纤毛虫通过细胞器隔离获得的光养进化

• 批准号: 2344641
• 负责人: Holly Moeller
• 金额: $ 49.31万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2344641&HistoricalAwards=false
• 关键词: Collaborative; Research; Evolution; acquired; phototrophy

This project offers a unique perspective into evolutionary processes that showcase both the extraordinary complexity of eukaryotic cells and help us to better understand how chloroplasts have spread around the tree of life. Research generated by this project will reveal adaptations for maintaining this cellular complexity in a unicellular organism, which has diverged from ancestors inhabiting ponds, estuaries, and sediment surface habitats, to become a major photosynthetic planktonic species in the world’s coastal oceans with wide reaching ecological roles. This transition is even more remarkable due its precariousness - its cellular and metabolic complexity and photosynthetic capabilities are the result of stealing and repurposing cell parts and genes of its algal prey. This research will determine how this process happens, and thereby shed some light on important, yet enigmatic, evolutionary processes. The project will help to train two postdoctoral scientists and prepare them for a professional career in scientific research. The project will also train undergraduate students in the laboratory, and will engage with the Zephyr Foundation, a marine science literacy and education program, which serves regional schools (levels 6-12), including districts with predominantly underrepresented groups in sciences. The project will also engage with the public in a collaboration with the Santa Barbara Museum of Natural History’s Underwater Parks Day to help educate the public about the oceans’ “invisible” (i.e., microscopic) biodiversity. The project will compare cellular, metabolic, and genetic adaptations across a genus of ciliates that span functional nutritional modes of heterotrophy to phototrophy, through a continuum of mixotrophy. Mixotrophy in Mesodinium is driven by organelle stealing (or kleptoplasty), which in M. chamaeleon evenly supports its nutritional and energy needs between feeding and photosynthesis. However, in M. rubrum it is more a means to steal organelles, including the active nucleus of its prey, to fully exploit its prey’s photosynthetic metabolism. Understanding how M. rubrum has adapted to be fully reliant on stolen organelles and their metabolism for its survival is one of the main objectives of this project. The project will use comparative omics approaches between these two species and the heterotroph, M. pulex, to illuminate genetic and metabolic adaptations and innovations. The project will also use spatial proteomics and immunochemistry, to understand how proteins from the stolen nucleus in M. rubrum transit to the chloroplasts, despite massive reorganization and loss of endomembrane continuity in their new host. The same techniques will also seek to understand what ciliate genes may be contributing to maintaining and controlling stolen organelles and facilitating exploitation of their metabolism.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目为进化过程提供了独特的观点，该过程既展示了真核细胞的非凡复杂性，又可以帮助我们更好地了解叶绿体如何在生命之树周围散布。该项目产生的研究将揭示用于维持这种细胞复杂性的改编，该组织与居住在池塘，河口和沉积物表面栖息地的祖先不同，成为世界沿海海洋中具有广泛生态角色的主要光合浮游物种。由于其不稳定性，这种过渡更加显着 - 其细胞和代谢的复杂性和照片同步能力是窃取和重新利用其藻类猎物的细胞部件和基因的结果。这项研究将决定这一过程的发生方式，从而确定了重要但神秘的进化过程。该项目将有助于培训两名博士后科学家，并为科学研究的职业生涯做好准备。该项目还将在实验室培训本科生，并与海洋科学素养和教育计划Zephyr Foundation（Zephyr Foundation）互动，该计划为地区学校提供服务（6-12级），其中包括科学领域代表性不足的地区。该项目还将与公众与圣塔芭芭拉自然历史博物馆的水下公园日合作，以帮助公众了解海洋的“隐形”（即微观）生物多样性。该项目将通过纤毛属的纤毛属进行细胞，代谢和遗传适应性，这些纤毛属，这些纤毛跨性别营养模式通过混合营养的连续性来比较杂果的功能营养模式。中丁菌中的混合肉体是由细胞器窃取（或kleptopplasty）驱动的，在Chamaeleon M. Chamaeleon中，它均匀地支持其营养和能量在喂养和光合作用之间。但是，在M. rubrum中，这更多的是窃取包括其猎物的活性核的细胞器，以充分利用其猎物的光合物代谢。了解M. Rubrum是如何适应对被盗的细胞器及其生存的新陈代谢的完全责任的，这是该项目的主要目标之一。该项目将使用这两种物种与异育菌（M. pulex）之间的比较法律方法来阐明遗传和代谢适应和创新。该项目还将使用空间蛋白质组学和免疫化学，以了解M. rubrum M. rubrum M. croment的蛋白如何转移到叶绿体，大规模重组以及其新宿主中内膜连续性的丧失。相同的技术还将寻求了解哪些纤毛基因可能有助于维护和控制被盗的细胞器并支持对其新陈代谢的剥削。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来通过评估来诚实地认为，通过评估来诚实地支持。