Change in direction of flagellar rotation is the basis of the chemotactic response in Escherichia coli
Change in direction of flagellar rotation is the basis of the chemotactic response in Escherichia coli
复制标题
鞭毛旋转方向的改变是大肠杆菌趋化反应的基础
作者：
S. H. Larsen;R. W. Reader;E. N. Kort;W. Tso;J. Adler
伯格和安德森最近根据现有证据提出，细菌通过螺旋鞭毛的旋转来游泳。Silver-MAN和SiMON2现在已经为这一点提供了明确的证明。通过针对鞭毛成分的抗体，他们将细胞系在显微镜载玻片上或彼此之间，观察细胞体的旋转。这些细胞可以停止，也可以朝任何一个方向旋转。正如他们提出的那样，鞭毛旋转的停止或逆转似乎可能与细菌的趋化性有关。因此，我们使用野生型和趋化缺陷的大肠杆菌突变细胞，以类似于Silverman和SiMON2的方式将其拴在显微镜载玻片上，并通过突然增加趋化剂来刺激它们。我们发现鞭毛旋转方向的变化确实构成了趋化性的基础：添加引诱剂会引起逆时针(CCW)旋转，而排斥剂会引起顺时针(CW)旋转。
BERG and Anderson1 recently argued from existing evidence that bacteria swim by rotation of their helical flagella. Silver-man and Simon2 have now provided a clear demonstration of this. By means of antibodies specific for flagellar components, they tethered cells to microscope slides or to each other and observed rotation of the cell bodies. The cells were able to stop and to rotate in either direction. It seemed possible, as they proposed2, that cessation, or reversal of flagellar rotation might be involved in bacterial chemotaxis. Accordingly, we used wild-type and chemotaxis-defective mutant cells of Escherichia coli tethered to microscope slides in a manner similar to that of Silverman and Simon2, and stimulated them by sudden increases of chemotactic agents. We found that changes in the direction of flagellar rotation indeed constitute the basis of chemotaxis: addition of attractants causes counter clockwise (CCW) rotation, whereas repellents cause clockwise (CW) rotation.