Study of the interplay of motility mechanisms during swaming of Myxococcus xanthu

黄粘球菌游动过程中运动机制相互作用的研究

• 批准号: 8332763
• 负责人: Mark Alber
• 金额: $ 25.96万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8332763
• 关键词: Adhesions; Affect; Algorithms; Bacillus subtilis; Bacteria; Behavior; Binding; Biological; Biology; Carbon; Cell Adhesion; Cell Communication; Cell Count; Cell Density; Cell model; Cell surface; Cells; Chemicals; Computer Simulation; Coupled; Cues; Data; Data Set; Detection; Elasticity; Elements; Environment; Event; Flagella; Goals; Image; Image Analysis; Individual; Instruction; Laboratories; Measures; Methods; Microscopy; Modeling; Motion; Movement; Myxococcales; Myxococcus xanthus; New Territories; Organism; Outcome; Pattern; Pilum; Polysaccharides; Probability; Process; Production; Proteus mirabilis; Pseudomonas aeruginosa; Resolution; Role; Running; Sagittaria; Serratia liquefaciens; Shapes; Signal Transduction; Site; Social Interaction; Soil; Speed; Surface; System; Techniques; Testing; Three-Dimensional Image; Time; Viscosity; Work; base; capsule; cell determination; cell motility; density; design; extracellular; flexibility; improved; insight; mathematical model; member; molecular scale; movie; multi-scale modeling; mutant; pathogen; research study; response; retinal rods; simulation; three-dimensional modeling; water environment

DESCRIPTION (provided by applicant): One of the most important emerging behaviors in biology is swarm formation. Many species of bacteria swarm, including species found in diverse soil and water environments such as Bacillus subtilis, Serratia liquefaciens, Proteus mirabilis, Pseudomonas aeruginosa, and Myxococcus xanthus. These and other swarming bacteria span the gamut of utility and range from innocuous carbon-cycle organisms to harmful pathogens. Swarming is observed in cells that are propelled by rotating flagella, by the secretion of slime, and by retracting type IV pili. Bacteria move on substrates and change their local environment in a way that improves cellular physical interaction and optimizes swarming. M. xanthus, a rod-shaped, Gram negative myxobacterium is able to glide on surfaces using two genetically independent yet cooperative A and S motility engines. These bacteria produce slime and move on slime tracks produced by other members of the colony. Remarkably, these bacteria also regularly reverse their gliding directions. The main goal of this proposal is to combine simulations using new three-dimensional multiscale modeling environment and specifically designed experiments to study basic coordination events of M. xanthus swarming, which is essential to understanding how millions of bacteria function in real environments. Specifically, we will study the role of flexibility of cells, viscosity of extracellular polysaccharide, slime adhesivity and directional reversals in resolving collisions, increasing alignment and optimizing swarming rate during swarming of mutant strains (A+S-) and ( A-S+) and wild type (A+S+) of M. xanthus. Predictive simulations will yield new biological hypotheses about M. Xanthus swarming because of the ability to conduct "experiments" in silico that are yet difficult (or impossible) to perform physically. A key aspect of this work will be to compare predictions obtained in silico with experimental observations. Study of the M. xanthus social interactions will provide an opportunity to gain fundamental insight into the biological response to how organisms discern, process, and respond to the chemical, physical, and biological cues present in their local environment.

描述（由申请人提供）：生物学中最重要的新兴行为之一是群体形成。许多细菌群落，包括在不同土壤和水环境中发现的细菌，如枯草芽孢杆菌、液化沙雷氏菌、奇异变形杆菌、铜绿假单胞菌和黄色粘球菌。 这些细菌和其他群居细菌的用途广泛，从无害的碳循环生物到有害的病原体。在由旋转鞭毛、分泌粘液和回缩 IV 型菌毛推动的细胞中观察到集群现象。细菌在基质上移动并改变其局部环境，从而改善细胞物理相互作用并优化群聚。 M. xanthus 是一种杆状革兰氏阴性粘细菌，能够使用两个遗传上独立但相互协作的 A 和 S 运动引擎在表面上滑动。这些细菌产生粘液，并在菌落其他成员产生的粘液轨道上移动。值得注意的是，这些细菌也经常改变它们的滑动方向。 该提案的主要目标是结合使用新的三维多尺度建模环境的模拟和专门设计的实验来研究 M. xanthus 集群的基本协调事件，这对于了解数百万细菌在真实环境中如何发挥作用至关重要。具体来说，我们将研究细胞的灵活性、胞外多糖的粘度、粘液粘附性和方向反转在突变菌株（A+S-）和（A-S+）群聚过程中解决碰撞、增加排列和优化群聚率的作用，以及M. xanthus 的野生型 (A+S+)。预测模拟将产生关于 M. Xanthus 群聚的新生物学假设，因为能够在计算机中进行“实验”，而这些实验在物理上却很难（或不可能）进行。这项工作的一个关键方面是将计算机中获得的预测与实验观察结果进行比较。对 M. xanthus 社会互动的研究将为深入了解生物体如何识别、处理和响应当地环境中存在的化学、物理和生物线索的生物反应提供机会。