Shi W, Li C, Louise C J, Adler J
Department of Genetics, College of Agricultural and Life Sciences, University of Wisconsin-Madison 53706.
J Bacteriol. 1993 Apr;175(8):2236-40. doi: 10.1128/jb.175.8.2236-2240.1993.
Escherichia coli lacks flagella when grown in tryptone broth in the presence of various adverse conditions (C. Li, C. J. Louise, W. Shi, and J. Adler, J. Bacteriol. 175:2229-2235, 1993). Now, the synthesis, rather than the degradation, of flagellin was shown to be inhibited. Studies of transcriptional fusions of flagellar operons to the lacZ gene revealed that transcription of the flagellar genes was reduced in cells grown under these adverse conditions. Increasing gene dosage of the flhD operon by a plasmid partially suppressed the nonflagellation caused by some adverse conditions. The signal which shuts off the synthesis of flagella under adverse conditions remains to be discovered. This shutting-off process does not result from catabolite repression or from signals from the chemotaxis system.
在各种不利条件下，大肠杆菌在胰蛋白胨肉汤中生长时缺乏鞭毛（C. Li、C. J. Louise、W. Shi和J. Adler，《细菌学杂志》175:2229 - 2235，1993年）。现在发现，鞭毛蛋白的合成而非降解受到抑制。对鞭毛操纵子与lacZ基因的转录融合研究表明，在这些不利条件下生长的细胞中，鞭毛基因的转录减少。通过质粒增加flhD操纵子的基因剂量可部分抑制某些不利条件导致的无鞭毛现象。在不利条件下关闭鞭毛合成的信号仍有待发现。这种关闭过程并非由分解代谢物阻遏或趋化系统的信号引起。
