Tracking phototactic responses and modeling motility of Synechocystis sp strain PCC6803
Tracking phototactic responses and modeling motility of Synechocystis sp strain PCC6803
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DOI：
10.1016/j.jphotobiol.2008.01.012
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发表时间：
2008-05-29
影响因子：
5.4
通讯作者：
Bhaya, Devaki
中科院分区：
文献类型：
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作者：
Burriesci, Matthew;Bhaya, Devaki
单细胞蓝细菌聚胞藻sp.菌株PCC 6803表现出沿表面向光源移动的趋光性。这个过程需要IV型菌毛和光敏色素样光感受器耦合到一个复杂的信号转导途径。细胞经过相互作用的不同阶段，才发展出向光方向移动的手指状突起，这是趋光性的特征。为了探究在趋光性初始阶段单个细胞之间的相互作用，我们对大量细胞进行了跟踪和分析。我们观察到单个细胞的运动性有限，但当细胞分裂和/或聚集到一定最小的群体大小时，观察到运动性和趋光性增强。在运动的后期，有明显的趋光行为，导致手指状突起的出现。我们的研究结果表明，细胞更喜欢移动到其他细胞以前穿过的区域，并将自己限制在这些区域，细胞改变局部表面特征，从而增强运动性。基于细胞跟踪数据，我们提出了一个初步的随机游走模型，该模型显示了可能相互作用以产生趋光性和运动性的典型阶段的力。在这个模型中，我们可以模拟具有趋光性特征的手指状突起的形成。(C) 2008 Elsevier B.V.版权所有
The unicellular cyanobacterium Synechocystis sp. Strain PCC 6803 exhibits phototaxis by moving along a surface towards a light source. This process requires Type IV pili and a phytochrome-like photoreceptor coupled to a complex signal transduction pathway. Cells progress through different phases of interaction before the development of finger-like projections moving in the direction of the light that are characteristic of phototaxis. To probe the interaction between individual cells during the initial phase of phototaxis we tracked and analyzed a large number of cells. We observed that individual cells have limited motility, but when cells divide and/or aggregate to attain a certain minimal group size, enhanced motility and phototaxis is observed. At the later stages of motility, there is noticeable phototactic behavior which results in the appearance of the finger-like projections. Our results indicate that cells prefer to move over areas previously traversed by other cells and confine themselves to these areas and that cells alter local surface characteristics allowing for enhanced motility. Based on cell tracking data we present a preliminary random walk model showing the forces that might interact to create the typical phases of phototaxis and motility. In this model, we can simulate the formation of finger-like projections that are characteristic of phototaxis. (C) 2008 Elsevier B.V. All rights reserved.