Visualizing Flagella while Tracking Bacteria.
Visualizing Flagella while Tracking Bacteria.
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DOI：
10.1016/j.bpj.2016.05.053
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发表时间：
2016-08
影响因子：
3.4
通讯作者：
L. Turner;L. Ping;Marianna Neubauer;H. Berg
中科院分区：
文献类型：
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作者：
L. Turner;L. Ping;Marianna Neubauer;H. Berg
对细菌游泳行为的完整描述需要测量细胞体的位移和方向，以及对鞭毛运动的描述。我们重建了一个跟踪显微镜，以便我们可以通过荧光观察跟踪细胞的鞭毛细丝。我们研究了大肠杆菌（各种长度的细胞，包括群细胞）、枯草芽孢杆菌（野生型和鞭毛较少的突变型）和运动链球菌（现在的肠球菌）。不管细胞的形状、长度和鞭笞程度如何，奔跑和翻滚的统计数据几乎是相同的；然而，群体细胞很少翻滚，并且肠细胞在缓慢移动时倾向于绕圈游动。在一些事件中，细丝经历了多态转变，但仍保持在束状，导致运动方向上的小偏转。翻滚速度是奔跑速度的2/3，当细胞游得更快时，奔跑或翻滚时游泳方向的变化率更小。如果参与翻滚的细丝数量较少，翻滚的间隔时间就会更短，翻滚的角度也会更小。
A complete description of the swimming behavior of a bacterium requires measurement of the displacement and orientation of the cell body together with a description of the movement of the flagella. We rebuilt a tracking microscope so that we could visualize flagellar filaments of tracked cells by fluorescence. We studiedEscherichia coli(cells of various lengths, including swarm cells),Bacillus subtilis(wild-type and a mutant with fewer flagella), and a motileStreptococcus(nowEnterococcus). The run-and-tumble statistics were nearly the same regardless of cell shape, length, and flagellation; however, swarm cells rarely tumbled, and cells ofEnterococcustended to swim in loops when moving slowly. There were events in which filaments underwent polymorphic transformations but remained in bundles, leading to small deflections in direction of travel. Tumble speeds were ∼2/3 as large as run speeds, and the rates of change of swimming direction while running or tumbling were smaller when cells swam more rapidly. If a smaller fraction of filaments were involved in tumbles, the tumble intervals were shorter and the angles between runs were smaller.