filamentous cells 11µm/s: wildtype cells 19µm/s µm/s
|Bacteria Escherichia coli
|Young KD. The selective value of bacterial shape. Microbiol Mol Biol Rev. 2006 Sep70(3):660-703 DOI: 10.1128/MMBR.00001-06 p.679 left column bottom paragraphPubMed ID16959965
| Maki N, Gestwicki JE, Lake EM, Kiessling LL, Adler J. Motility and chemotaxis of filamentous cells of Escherichia coli. J Bacteriol. 2000 Aug182(15):4337-42.PubMed ID10894745
|Primary source abstract: "Filamentous cells of Escherichia coli can be produced by treatment with the antibiotic cephalexin, which blocks cell division but allows cell growth. To explore the effect of cell size on chemotactic activity, [investigators] studied the motility and chemotaxis of filamentous cells. The filaments, up to 50 times the length of normal E. coli organisms, were motile and had flagella along their entire lengths."
|P.679 left column bottom paragraph: "Maki et al. examined one facet of this equation by creating motile E. coli filaments 7.5 to 10 μm long that respond to chemical gradients as well as normal-sized E. coli (primary source). These filamentous cells do not tumble, and therefore they cannot run and tumble. Instead, after moving in a straight line for a while, they stop and then either reverse direction or continue along their original path (primary source). Filamentous cells move more slowly (11 μm/s, versus 19 μm/s for the wild type), and mutations that provoke normal rods to tumble continuously cause the filaments to stop completely, or, in the authors' vivid words, the mutant filaments stop and “gently thrash about” (primary source). The point is, if a cell is too long it cannot tumble to search for the most appropriate direction toward a chemoattractant or away from a repellent. Therefore, cells longer than a certain length will be counterselected because they cannot follow a gradient to its source or, if they can, will do so more slowly."