DNA replication a checkpoint in regulating development in Myxococcus xanthus

Mitchell SingerDNA复制在调节黄色粘球菌发育中的检查点Proposal编号：1354562项目摘要：了解单个细胞如何与环境相互作用，以及环境如何塑造和调节细胞的生长和分化，对所有生命来说都是基本的，从细菌等单细胞生物到人类等复杂的多细胞生物。这个项目解决了这个基本问题，关于黄色粘球菌，一种简单的发育细菌系统。黄色微囊藻细胞生长在被称为生物膜的社会群体中，在这个群体中，生长的细胞将它们分泌的消化酶汇集在一起，从环境中分解复杂的大分子。当营养物质变得有限时，黄花莲的反应是启动一个发育程序，导致构建一种称为子实体的多细胞结构。在这个结构中，一个亚群的细胞形成耐环境的粘孢子。这个项目特别关注于确定促进粘孢子形成的分子机制，而其他细胞要么自我破坏，要么形成一种不同类型的细胞，称为外周杆状细胞。这个项目测试了一种假设，即细胞(孢子、杆状或死亡)的命运取决于它在细胞分裂周期中遇到开始子实体形成的信号时所走的距离。实验旨在使用分子、生物化学和生理学方法来验证这一假说。该项目有望促进我们对细菌发育、分子信号和饥饿生理学的理解。黄曲霉是一个药理上重要的细菌家族的代表，其抗生素、抗肿瘤和抗真菌化合物的产生与多细胞发育密切相关。该项目将继续作为对研究生、本科生和高中生的实验室培训，这些学生将继续长期从事科学工作。最后，该项目为当地一所小学提供社区外展服务。

Mitchell SingerDNA replication a checkpoint in regulating development in Myxococcus xanthusProposal number: 1354562Project Abstract:Understanding how individual cells interact with their environment and how that environment shapes and regulates cell growth and differentiation is fundamental to all life, from single celled organisms such as bacteria, to complex multicellular organisms such as humans. This project addresses this basic question, with respect to Myxococcus xanthus, a simple developmental bacterial system. M. xanthus cells grow in social groups called biofilms, in which the growing cells pool their secreted digestive enzymes to breakdown complex large molecules from the environment. When nutrients become limiting, M. xanthus responds by activating a developmental program that results in the construction of a multicellular structure called a fruiting body. Within this structure, a subpopulation of cells forms environmentally resistant myxospores. This project specifically focuses on determining the molecular mechanisms that promote the formation of myxospores, while other cells either undergo self-destruction or form a different type of cell called a peripheral rod cell. This project tests the hypothesis that the fate of a cell (spore, rod, or death) is determined by how far along it is in the cell division cycle when it encounters the signal to begin fruiting body formation. Experiments are designed to test this hypothesis using molecular, biochemical and physiological approaches. The project is expected to advance our understanding of bacterial development, molecular signaling, and starvation physiology. M. xanthus is a representative of a family of pharmacologically important bacteria, whose production of antibiotic, anti-tumor and anti-fungal compounds is tied to multicellular development. This project will continue to serve as laboratory training to graduate, undergraduate and high school students, who will continue with long-term careers in science. Finally this project provides community outreach to a title 1 local elementary school.