COMPLEX PROCESSES IN MULTICELLULAR BACTERIA

多细胞细菌的复杂过程

• 批准号: 2283637
• 负责人: NEIL H MENDELSON
• 金额: $ 13.17万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-06-01 至 1998-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2283637
• 关键词: Bacillus subtilis; bacterial genetics; biological models; biological signal transduction; cell cell interaction; cell growth regulation; gene expression; microorganism growth

The regulation of processes such as growth, gene expression, and morphogenesis in higher organisms is difficult to study due to the complex nature of interactions that go on in the context of multicellularity. The objective of the work proposed here is to develop a parallel model system using procaryotes in which the contributions of individual cells to the properties of the multicellular "organism," be it a bacterial macrofiber or a colony, can be precisely determined. The long-range goal is to eventually understand the relationships between genetic, biomechanical, and other factors that govern higher order complexity in organisms. Such relationships have broad significance in health-related sciences. The specific aims of the experiments described in this proposal lie in three areas: (i) to ascertain the means by which individual cell growth leads to the formation of complex three-dimensional, multicellular helical fibers of given hand and degree of twist, (ii) to obtain estimates of the forces produced during growth of cells from measurements of motions, and (iii) to characterize the newly discovered system of nutrient depletion gradient fields that governs gene expression at a particular time and place within colonies of Bacillus subtilis. The first two projects shall include examination of multi-strand helix formation starting from single cells, analysis of the underlying mechanics, and development of super-coiling models related to the observed geometry. Helix hand inversion and growth under artificial constraints will also be studied. Time-lapse and laser tweezer methods will be used. The gene expression project will involve a thorough examination of the patterns of gene expression during colony growth and, in macrofibers, characterization of the signalling system, analysis of the relationship between cell growth geometry and the pattern of gene expression obtained, identification and possibly purification of the signaller, and identification of the gene(s) that govern signal production and response to the signaller. Microbiological, biochemical, genetic, and molecular genetic approaches will be used in these studies.

调节生长，基因表达和等过程的调节 由于复合物，很难研究较高生物体的形态发生 在多细胞性背景下发生的相互作用的性质。这 这里提出的工作的目的是开发平行模型系统 使用丙烯酸酯，其中单个细胞对 多细胞“生物”的特性，无论是细菌宏观纤维 或殖民地，可以精确确定。远程目标是 最终了解遗传，生物力学， 以及控制生物体中高阶复杂性的其他因素。这样的 关系在与健康相关的科学中具有广泛的意义。这 该提案中描述的实验的具体目的在于三个 区域：（i）确定单个细胞生长导致的手段 复杂的三维多细胞螺旋纤维的形成 给定的手和扭曲程度，（ii）获得力估计 从运动测量和（iii）到细胞生长期间产生 表征新发现的营养耗尽梯度系统 在特定时间和位置控制基因表达的字段 枯草芽孢杆菌的菌落。前两个项目应包括 检查从单细胞开始的多链螺旋形成， 分析基础力学和超级融化的发展 与观察到的几何形状有关的模型。螺旋手动和增长 在人造限制下也将进行研究。延时和激光 将使用镊子方法。基因表达项目将涉及 彻底检查菌落中基因表达的模式 生长，在大纤维中，信号系统的表征， 分析细胞生长几何形状与模式之间的关系 获得的基因表达，识别和可能纯化 信号和控制信号的基因的识别 对信号者的生产和响应。微生物学，生化， 这些研究将使用遗传和分子遗传学方法。