Cellular Dynamics Drives the Emergence of Supracellular Structure in the Cyanobacterium, Phormidium sp. KS.
Cellular Dynamics Drives the Emergence of Supracellular Structure in the Cyanobacterium, Phormidium sp. KS.
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DOI：
10.3390/life4040819
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发表时间：
2014-11-28
期刊：
影响因子：
--
通讯作者：
Tajima N
中科院分区：
文献类型：
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作者：
Sato N;Katsumata Y;Sato K;Tajima N
运动丝状蓝藻，如颤藻属、席藻属和节旋藻属，广泛存在于陆地和水生环境中。正如Nägeli在1860年所指出的，它们中的许多形成复杂的三维或二维结构，如生物膜，杂草状菌体，丝束和螺旋，我们称之为超细胞结构。在所有这些结构中，单个的纤维不断地来回移动。因此，这些结构是宏观的、动态的结构，它们不断地改变着它们的微观细丝排列。在本研究中，我们定量分析了席藻藻KS的单根丝状体在琼脂平板上的运动。连接孔，这已被提出来驱动细胞运动的粘液/粘液分泌，被发现在每个隔膜的两侧对齐。运动的速度是最高的方向反转后，然后，指数衰减到一个最终值之前的下一个方向反转。这种动力学与“粘液枪”模型是相容的。较高的琼脂浓度限制运动更严重，因此，导致更多的螺旋形成。螺旋线是一种稳健的形式，与长灯丝不同部分的非均匀运动兼容。我们提出了一个模型的螺旋形成的基础上的微观运动的细丝。
Motile filamentous cyanobacteria, such as Oscillatoria, Phormidium and Arthrospira, are ubiquitous in terrestrial and aquatic environments. As noted by Nägeli in 1860, many of them form complex three-dimensional or two-dimensional structures, such as biofilm, weed-like thalli, bundles of filaments and spirals, which we call supracellular structures. In all of these structures, individual filaments incessantly move back and forth. The structures are, therefore, macroscopic, dynamic structures that are continuously changing their microscopic arrangement of filaments. In the present study, we analyzed quantitatively the movement of individual filaments of Phormidium sp. KS grown on agar plates. Junctional pores, which have been proposed to drive cell movement by mucilage/slime secretion, were found to align on both sides of each septum. The velocity of movement was highest just after the reversal of direction and, then, attenuated exponentially to a final value before the next reversal of direction. This kinetics is compatible with the “slime gun” model. A higher agar concentration restricts the movement more severely and, thus, resulted in more spiral formation. The spiral is a robust form compatible with non-homogeneous movements of different parts of a long filament. We propose a model of spiral formation based on the microscopic movement of filaments.