CAREER: Experimental Investigation of Morphogenesis and Locomotion of Multicellular Magnetotactic Bacteria

多细胞趋磁细菌聚集体的研究将阐明多细胞生命进化的物理机制。这些聚集体在协调其组成细胞的生长和集体运动方面具有独特的能力。理解这种能力将有助于仿生微系统的设计。该研究是第一次对多细胞趋磁细菌的生长、形态和流体动力学进行综合实验和理论研究。PI将设计一门关于“生物复杂性建模”的新课程。与传统的生物物理学课程不同，本课程将侧重于研究和模拟非培养细菌、微生物群落、生态系统和营养循环所需的工具和技术。本课程将帮助学生准备应对气候变化的挑战。将招收各层次的学生加入PI的研究小组。PI将参加科学展览。PI将设计新的演示，让公众在显微镜下观察活的多细胞趋磁细菌，并使用磁铁引导它们。该项目旨在了解促进多细胞生命进化的物理机制。多细胞趋磁细菌是一种介于单细胞和多细胞之间的生物。这些细菌只生活在由10-60个细胞组成的球形聚集体中，这些细胞一旦与聚集体分离就会迅速死亡。聚集在一起的细胞沉淀出磁性晶体，这些晶体排列在一个共同的方向上。这些细胞一起工作，沿着磁力线推动聚集体。当细胞在聚集体中繁殖时，聚集体生长、拉长并分裂成两个大小相似的聚集体。这种显著合作行为背后的物理机制尚不清楚。我们不知道细胞是如何协调它们的生长，排列它们的磁矩，以及协调它们的运动。该项目将通过实验和理论的结合，研究细胞在生长和旋转鞭毛时如何相互作用，使细胞表现得像一个单一的多细胞生物。这些类型的相互作用可能通过允许原始多细胞群体中的细胞在共享化学信号通路进化之前进行合作，促进了复杂生命的进化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The study of Multicellular Magnetotactic Bacteria aggregates will elucidate the physical mechanisms underlying the evolution of multicellular life. These aggregates are unique in their ability to coordinate the growth and collective motion of their constituent cells. Understanding this ability will contribute to the design of biomimetic micro-systems. The proposed research is the first integrated experimental and theoretical study of the growth, form, and hydrodynamics of Multicellular Magnetotactic Bacteria. The PI will design a new course on "Modeling Biological Complexity." Unlike traditional biophysics courses, the course will focus on the tools and techniques necessary to study and model uncultured bacteria, microbial communities, ecosystems, and nutrient cycles. This course will help prepare students to address the challenges of climate change. Students of all levels will be recruited to join the PI's research group. The PI will participate in science expositions. The PI will design new demonstrations that will allow members of the public to observe living Multicellular Magnetotactic Bacteria under a microscope and guide them using magnets.The project aims to understand the physical mechanisms that facilitate the evolution of multicellular life. The research focuses on Multicellular Magnetotactic Bacteria, which represent an intermediate between unicellular and multicellular life. These bacteria live exclusively in spherical aggregates composed of 10–60 cells, which quickly die when separated from the aggregate. Cells in an aggregate precipitate magnetic crystals, which align in a common direction. The cells work together to push the aggregate along magnetic field lines. As cells in an aggregate reproduce, the aggregate grows, elongates, and divides into two similarly sized aggregates. The physical mechanisms that underlie this remarkable cooperative behavior are poorly understood. It is not known how cells coordinate their growth, align their magnetic moments, and coordinate their motility. The project will investigate, through a combination of experiment and theory, how the interactions between cells as they grow and rotate their flagella allow the cells to behave like a single multicellular organism. These types of interactions may have facilitated the evolution of complex life by allowing cells in a proto-multicellular group to cooperate before the evolution of shared chemical signaling pathways.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.