Cellular and metabolic integration of symbiotic organelles in the ciliate Mesodinium rubrum

光合生命（植物和藻类）由于共生相互作用而具有复杂的进化历史，共生相互作用导致叶绿体（光合细胞器）在不相关的生物群体之间转移。虽然有大量的证据表明共生在这些进化事件中的作用，但关于生物体如何适应成为“绿色”却知之甚少。该项目将研究叶绿体形成的早期事件，以及生物体如何在缺乏必要基因的情况下重组其整个代谢以利用光合作用。研究人员将重点关注一种常见的海洋纤毛虫，这种纤毛虫以一种特定的藻类为食，并窃取其细胞机器（即细胞器：叶绿体，线粒体和细胞核）。纤毛虫能够将这些细胞器整合到自己的细胞中，甚至在细胞分裂时复制它们，通过利用从临时被盗的细胞核表达的基因。研究人员将使用下一代（转录组学，蛋白质组学，代谢组学）和传统（显微镜，细胞生理学）技术来发现生物体如何适应光合代谢并将外来细胞器整合到自己的细胞中。研究人员将专注于纤毛虫如何能够窃取细胞核并促进其基因表达，以及随后将蛋白质靶向回其细胞内重组的被盗细胞器。这个外来的细胞核不能在纤毛虫中分裂，因此必须在细胞分裂后通过进食来常规地替换。这些结果将广泛应用于共生（包括寄生）的研究，并将重塑我们如何看待共生在真核生物进化中的作用。研究人员将与Zephyr教育基金会合作，与学生（8-12年级）合作，扩大海洋科学素养并教授共生。他们还将通过实验室研究项目培训代表性不足的本科生。

Photosynthetic life (plants and algae) has a complex evolutionary history due to symbiotic interactions that have resulted in the transfer of chloroplasts (the photosynthetic organelle) among unrelated groups of organisms. While there is abundant evidence for the role of symbiosis in these evolutionary events, little is known regarding how organisms adapt to become "green". This project will investigate early events in the acquisition of a chloroplast and how an organism has restructured its entire metabolism in order to use photosynthesis, despite lacking the genes necessary to run it. The investigators will focus on a common marine ciliate that is known to feed on one particular group of algae, and steal its cellular machinery (i.e. the organelles: chloroplasts, mitochondria, and nucleus). The ciliate is able to incorporate these organelles into its own cell, and even replicate them as the cell divides, by utilizing genes expressed from the temporary stolen nucleus. The investigators will use next generation (transcriptomics, proteomics, metabolomics) and traditional (microscopy, cell physiology) techniques to discover how organisms can adapt to a photosynthetic metabolism and incorporate foreign organelles into their own cell. The investigators will focus on how the ciliate is able to steal a nucleus and facilitate its gene expression, and the subsequent targeting of proteins back to the stolen organelles that are reorganized within its cell. This foreign nucleus cannot divide in the ciliate, and therefore must be routinely replaced by feeding after the cell divides. These results will have broad applications to studies of symbiosis (including parasitism), and will reshape how we think about the role of symbiosis in eukaryotic evolution. The investigators will work with students (grades 8-12) in collaboration with the Zephyr Education Foundation, to expand marine science literacy and to teach about symbiosis. They will also train under-represented undergraduates through laboratory research projects.