Gliding motility driven by individual cell-surface movements in a multicellular filamentous bacterium Chloroflexus aggregans
Gliding motility driven by individual cell-surface movements in a multicellular filamentous bacterium Chloroflexus aggregans
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DOI：
10.1093/femsle/fnw056
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发表时间：
2016-04-01
影响因子：
2.1
通讯作者：
Haruta, Shin
中科院分区：
文献类型：
--
作者：
Fukushima, Shun-ichi;Morohoshi, Sho;Haruta, Shin
聚集绿弯曲菌是一种具有滑行运动能力的多细胞丝状细菌。细丝以恒定的速率直线运动，类似于固体表面上的3 μ m/sec（-1），偶尔会反转运动方向。在这项研究中，我们成功地检测到细胞表面的玻璃珠沿着长轴的细丝，表明细胞表面的运动是滑动的直接力。显微镜分析发现，细胞表面的运动仅限于一个细胞的细丝，每个细胞独立地移动和逆转的方向。为了理解细胞运动如何决定细丝的运动方向，我们提出了一个离散时间随机模型，细胞运动方向之和仅在细丝暂停时决定细丝的运动方向，运动后细丝保持相同的方向运动，直到所有细胞暂停和/或向相反方向运动。MonteCarlo模拟结果表明，长纤维的反转频率相对固定，且较低，而短纤维的反转频率变化较大。该模拟结果恰当地解释了实验观察结果。本研究提出了能充分描述C.聚集体
Chloroflexus aggregans is an unbranched multicellular filamentous bacterium having the ability of gliding motility. The filament moves straightforward at a constant rate, similar to 3 mu m sec(-1) on solid surface and occasionally reverses the moving direction. In this study, we successfully detected movements of glass beads on the cell-surface along long axis of the filament indicating that the cell-surface movement was the direct force for gliding. Microscopic analyses found that the cell-surface movements were confined to a cell of the filament, and each cell independently moved and reversed the direction. To understand how the cellular movements determine the moving direction of the filament, we proposed a discrete-time stochastic model; sum of the directions of the cellular movements determines the moving direction of the filament only when the filament pauses, and after moving, the filament keeps the same directional movement until all the cells pause and/or move in the opposite direction. Monte Carlo simulation of this model showed that reversal frequency of longer filaments was relatively fixed to be low, but the frequency of shorter filaments varied widely. This simulation result appropriately explained the experimental observations. This study proposed the relevant mechanism adequately describing the motility of the multicellular filament in C. aggregans.