Ultrastructural Complexity in Unconventional Cells

非常规细胞的超微结构复杂性

• 批准号: RGPIN-2019-03986
• 负责人: Leander, Brian
• 金额: $ 5.03万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=714464
• 关键词: Ultrastructural; Complexity; Unconventional; Cells

Single-celled organisms have dominated the planet for over 3 billion years, yet their traits are the least understood of all extant organisms. Of the three major lineages of microbial life, single-celled eukaryotes are the most complex. Unlike bacteria and archaea, eukaryotic cells have nuclei, endomembrane systems, endosymbiotically acquired organelles and elaborate cytoskeletons supporting a vast array of specialized cell extensions and behaviors. Our research program is designed to explore unconventional eukaryotes in order to help unravel the composition, interrelationships and innovative cellular traits in lineages that span the tree of life. The research aims to accelerate the discovery of novel single-celled eukaryotes and reconstruct complex ultrastructural systems using comparative molecular methods and high-resolution microscopy. A central goal in biology is to understand the function of complex structures and how they arose from simpler precursors. This is especially challenging in the field of comparative cell biology because these studies require sophisticated technologies, spatial reasoning at a fine scale and detailed terminology associated with unfamiliar organisms. Morphological complexity is normally associated with multicellularity, as seen in the camera-type eyes found in several groups of animals. However, some single-celled eukaryotes have also acquired extremely complex traits by arranging standard subcellular components in extraordinary ways. Dinoflagellates, for instance, represent a major lineage of eukaryotes with an unusually high level of cellular diversity. Our lab has shown that some dinoflagellates have an eye-like “ocelloid” consisting of subcellular analogues to a cornea, lens, iris and retina. These same species also have intricate harpoon-like “nematocysts”, some of which use a single pressurized capsule for propulsion, while others uniquely launch 11 to 15 projectiles from an arrangement similar to a Gatling gun. Comparative studies of traits like these offer idiosyncratic systems for tracing novel cases of convergence and the intermediate stages that gave rise to highly integrated structures. Research on the unity and diversity of complex ultrastuctural traits is exploratory and progresses in four principal phases: (1) collection of uncultivated organisms from diverse environments; (2) single-cell preparation and characterization using high-resolution microscopy (CLSM, FIB-SEM, TEM); (3) single-cell isolation for transcriptomics and genomics; (4) computational analyses associated with digital image processing and bioinformatics. Outcomes of this research accelerate the discovery of new traits in eukaryotic cells from diverse environments and identify novel ways in which single-celled organisms have solved basic problems, such as locomotion, feeding, defense and photoreception.

单细胞生物已经统治地球超过30亿年，但它们的特征是所有现存生物中最不为人所知的。在微生物生命的三个主要谱系中，单细胞真核生物是最复杂的。与细菌和古细菌不同，真核细胞有细胞核、膜系统、内共生获得的细胞器和复杂的细胞骨架，支持大量的特殊细胞扩展和行为。我们的研究计划旨在探索非常规的真核生物，以帮助解开跨越生命之树的谱系中的组成，相互关系和创新细胞特征。该研究旨在加速发现新的单细胞真核生物，并利用比较分子方法和高分辨率显微镜重建复杂的超微结构系统。