Sommer J M, Newton A
Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, New Jersey 08544.
Genetics. 1991 Nov;129(3):623-30. doi: 10.1093/genetics/129.3.623.
A pseudoreversion analysis was used to examine the role of cell division genes in polar morphogenesis in Caulobacter crescentus. Extragenic suppressors of temperature sensitive mutations in pleC, a pleiotropic gene required for cell motility, formation of polar phi CbK bacteriophage receptors, and stalk formation, were isolated. These suppressors, which restored motility at 37 degrees C, simultaneously conferred a cold sensitive cell division phenotype and they were mapped to the three new cell division genes divJ, divL and divK. The cold-sensitive mutations in divL, and to a lesser extent divJ, exhibited a relatively narrow range of suppression. The cold-sensitive cell division mutation in divK, by contrast, suppressed all pleC mutations examined and behaved as a classical bypass suppressor. The direct role of this cell division gene in the regulation of motility is suggested by the observation that divK341 mapped to the same locus as pleD301, a pleiotropic mutation that prevents loss of motility and stalk formation. These results provide strong evidence that the cell division and developmental pathways are interconnected and they support our earlier conclusion that cell division is required for the regulation of polar morphogenesis and differentiation in C. crescentus.
利用假回复分析来研究新月柄杆菌中细胞分裂基因在极性形态发生中的作用。分离出了pleC（一种对细胞运动、极性φCbK噬菌体受体形成和柄形成所必需的多效性基因）温度敏感突变的基因外抑制子。这些抑制子在37℃时恢复了运动性，同时赋予了冷敏感细胞分裂表型，并且它们被定位到三个新的细胞分裂基因divJ、divL和divK。divL中的冷敏感突变，以及程度较轻的divJ中的冷敏感突变，表现出相对较窄的抑制范围。相比之下，divK中的冷敏感细胞分裂突变抑制了所有检测的pleC突变，并表现为典型的旁路抑制子。divK341与pleD301位于同一基因座，pleD301是一种多效性突变，可阻止运动性丧失和柄形成，这一观察结果表明了该细胞分裂基因在运动性调节中的直接作用。这些结果提供了强有力的证据，证明细胞分裂和发育途径是相互关联的，并且支持了我们早期的结论，即细胞分裂是新月柄杆菌极性形态发生和分化调节所必需的。
