Chemotaxis without Conventional Two-Component System, Based on Cell Polarity and Aerobic Conditions in Helicity-Switching Swimming of Spiroplasma eriocheiris.
Chemotaxis without Conventional Two-Component System, Based on Cell Polarity and Aerobic Conditions in Helicity-Switching Swimming of Spiroplasma eriocheiris.
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DOI：
10.3389/fmicb.2017.00058
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发表时间：
2017
影响因子：
5.2
通讯作者：
Miyata M
中科院分区：
文献类型：
--
作者：
Liu P;Zheng H;Meng Q;Terahara N;Gu W;Wang S;Zhao G;Nakane D;Wang W;Miyata M
中华绒螯蟹螺原体是引起中华绒螯蟹大量死亡的病原菌。毛鳞棘球绦虫引起震颤病，感染几乎所有人工养殖的甲壳类动物，对中国水产养殖经济造成灾难性影响。S. eriocheiris是一种无壁螺旋状细菌，长度为2.0 ~ 10.0 μm，在没有鞭毛的粘性介质中，通过切换细胞螺旋从前端到尾部的扭结，可以以每秒5 μm的速度游动。在这项研究中，我们发现S. eriocheiris在没有传统的双组分系统（细菌趋化性中常见的系统）的情况下进行趋化。在厌氧条件下培养时，更能观察到毛毛单胞菌的趋化性。细胞呈两极分化，如尖端结构所证明的那样，沿着尖端的方向游动，并显示出对引诱物的反应而改变其游动方向。Triton X-100处理揭示了内部结构，一个哑铃形状的核心在尖端，由一条平坦的丝带连接，这条丝带沿着螺旋细胞形状中最短的线从尖端到另一极。质谱分析鉴定了16种蛋白质为其内部结构的组成成分，包括纤维蛋白和4种MreB蛋白。
Spiroplasma eriocheiris is a pathogen that causes mass mortality in Chinese mitten crab, Eriocheir sinensis. S. eriocheiris causes tremor disease and infects almost all of the artificial breeding crustaceans, resulting in disastrous effects on the aquaculture economy in China. S. eriocheiris is a wall-less helical bacterium, measuring 2.0 to 10.0 μm long, and can swim up to 5 μm per second in a viscous medium without flagella by switching the cell helicity at a kink traveling from the front to the tail. In this study, we showed that S. eriocheiris performs chemotaxis without the conventional two-component system, a system commonly found in bacterial chemotaxis. The chemotaxis of S. eriocheiris was observed more clearly when the cells were cultivated under anaerobic conditions. The cells were polarized as evidenced by a tip structure, swimming in the direction of the tip, and were shown to reverse their swimming direction in response to attractants. Triton X-100 treatment revealed the internal structure, a dumbbell-shaped core in the tip that is connected by a flat ribbon, which traces the shortest line in the helical cell shape from the tip to the other pole. Sixteen proteins were identified as the components of the internal structure by mass spectrometry, including Fibril protein and four types of MreB proteins.