Mathematical Sciences: Mathematical Models in Cellular & Developmental Biology

调查员和他的同事通过数学方法研究 建模和计算机模拟几种现象处理 细胞和细胞器运动的机械化学。 在 特别是，他们专注于有偏见的随机运动的作用， 在两个组织层次上建立秩序。 在细胞/组织 他们调查了细胞的随机运动 通过边界抑制自组织成组织几何形状， 细胞间通讯 在分子/细胞水平上， 研究了几种细胞内运动现象， 从随机热运动中提取功， 键能对棘轮分子的组装和分解起作用。 这项研究旨在解决细胞如何运动的基本问题 并在形态发生过程中改变形状， 是通过细胞膜运输的。 这些问题很重要 对于基本的理解，也有影响， 诸如伤口愈合和组织发育等问题。 在核糖体上蛋白质合成期间和之后， 多肽链必须穿过内膜 进入细胞内区室，如内质网， 线粒体 如何做到这一点是一个谜，因为 它似乎是在缺乏代谢能量的情况下进行的 例如核苷酸水解。 研究人员建议， 一种解释这一过程的机制， 氨基酸链的热运动可以通过 任何使链条难以运行的过程 反了 这些过程的例子是绑定 伴侣蛋白、糖基化和/或链折叠。 推进 细胞内病原体单核细胞增生李斯特菌的机制是 他们认为，另一个可行的过程是， 棘轮布朗运动 这种细菌通过 形成一条由交联的肌动蛋白丝组成的尾巴。 他们提议 通过模拟尾翼的耦合动力学来模拟这一过程 组装和细菌的布朗运动。

The investigator and his colleague study by mathematical modeling and computer simulation several phenomena dealing with the mechanochemistry of cell and organelle motions. In particular, they focus on the role of biased random motions in creating order at two levels of organization. At the cell/tissue level they investigate how apparently random cell motions can self organize into tissue geometries via boundary inhibitions and intercellular communication. At the molecular/cell level they examine several intracellular motility phenomena that appear to extract work from random thermal motions by employing chemical bond energy to ratchet molecular assembly and disassembly. This study aims at basic questions about how cells move and change shape during morphogenesis, and how macromolecules are transported across cell membranes. The issues are important for fundamental understanding, and also have implications for such problems as wound healing and the development of tissues. During and after protein synthesis on ribosomes the nascent polypeptide chains must be transported across internal membranes into intracellular compartments such as endoplasmic reticula and mitochondria. How this is accomplished is a mystery, for it appears to proceed in the absence of a metabolic energy source such as nucleotide hydrolysis. The investigators propose a mechanism to explain this process based on the idea that the thermal motions of the amino acid chain can be biased by any process that makes it difficult for the chain to go backwards. Examples of such processes are binding of chaperonins, glycosylation, and/or chain folding. The propulsion mechanism of the intracellular pathogen Listeria monocytogenes is another example of a process that works, they believe, by ratcheted Brownian motion. This bacterium drives itself by building a tail of cross-linked actin filaments. They propose to model this process by simulating the coupled dynamics of tail assembly and the Brownian motion of the bacterium.