Microswimming navigation in temperature and viscosity gradients

拟议的项目是对真核和原核单细胞（例如细菌、绿色藻类、精子细胞）在外部温度和粘度梯度中的运动进行研究。游泳细胞对温度变化的反应和温度梯度的变化，影响着群体密度的重新分布、生物膜的形成、感染的控制等。对于精子细胞，粘度和温度梯度被认为是受精成功的重要指导线索。温度，除了是一种外部信号，可以通过特定的受体被游泳细胞感觉到，也改变了环境的性质，如粘度或pH值。这使得温度和粘度的问题内在地联系在一起。尽管细胞趋热性的现象已经得到了很好的证实[1]，但该过程的细节和机制仍不清楚。然而，几乎没有研究过趋粘性[2]。该项目的挑战是了解细胞在微观和群体水平上对温度和粘度变化的动态响应。该研究将涉及在受控微流体环境中对单个游泳细胞和整体行为的多尺度测量，以及应用已识别的个体游泳者运动微观机制对种群动态进行数学建模。学生将学习和应用广泛的实验分析技术，如软光刻，微流体，视频显微镜，分子和微生物学方法，图像处理技术，布朗动力学模拟等。潜在的影响可以在设计新的概念以防止生物污染和改进人工授精技术中看到。R. Clegg等人，Eur. J. Phycol.，38，195（2003）; H. Salman，A. Libchaber，Nature Cell Biology 9，1098（2007）. [2] M.Yu.谢尔曼等人，FEMS微生物学通讯13，137（1982）EPSRC该项目与EPSRC研究领域“生物物理学和软物质物理学”相一致，因为感兴趣的问题跨越生物长度尺度，并将其与理解生物系统相关联。工业和学术合作伙伴该项目涉及英国各地的工业和学术合作伙伴：谢菲尔德大学伯恩霍尔诊所的Allan Pacey教授Genus Breeding Inc.

The proposed project is for undertaking a research on eukaryotic and prokaryotic unicellular motility (e.g. bacteria, green algae, sperm cells) in external temperature and viscosity gradients. It has been known that swimming cells respond to temperature changes and follow temperature gradients, which affects the population density redistribution, biofilm formation, infection control. For the sperm cells, the viscosity and temperature gradients have been regarded as important guiding cues in fertilisation success. Temperature, apart from being an external signal which can be sensed by swimming cells through specific receptors, also alters properties of the environment, such as viscosity or pH. This makes problems of thermo- and visco- taxes intrinsically linked. Despite the well-established phenomena of cells thermotaxis [1], the details and mechanisms of the process remain unclear. Viscotaxis though has been barely studied [2]. The challenge of the project is to understand cell's dynamic response on microscopic and population levels to the temperature and viscosity variations. The research will involve multiscale measurements of individual swimming cells and ensemble behaviour in controlled microfluidic environment, as well as mathematical modelling of the population dynamics applying identified microscopic mechanisms of motion for individual swimmers. The student will to learn and apply a wide range of experimental analytical techniques, such as soft lithography, microfluidics, video-microscopy, molecular and micro-biology methods, image processing techniques, Brownian dynamics simulations etc. throughout the research. The potential impact can be seen in designing novel concepts for preventing biofouling, and improvement of artificial insemination techniques.References[1] M. R. Clegg et al. Eur. J. Phycol., 38, 195 (2003); H. Salman, A. Libchaber, Nature Cell Biology 9, 1098 (2007).[2] M.Yu. Sherman, et al. FEMS Microbiology Letters 13, 137 (1982)EPSRCThe project is aligned within EPSRC research area 'Biophysics and soft matter physics', as the problem of interest ranges across biological length scales and relates it to understanding biological systems.Industrial and academic partnersThe project involves industrial and academic partners across the UK:Prof. Allan Pacey, University of SheffieldBourn Hall ClinicGenus Breeding Inc