Figure 1 Motility of YB3558, YB3559 and ctrA401. The swarm assay was performed as described in the Methods. The non-motile rpoN mutant and the polar development mutant ΔpodJ are included. YB3558 displays an intermediate swarming defect, between ΔpodJ and wild-type levels, similar to a ctrA temperature sensitive lethal allele grown under permissive conditions. Complementation of YB3558 with a wild-type ctrA gene under native control (YB3559) does not restore the swarming phenotype. Figure 2 Morphology of YB3558 and YB3559.
Phase micrographs of exponentially growing cultures of CB15, YB3558, ctrA401 and YB3559 at 30°C. YB3558 displays increased filamentation, find more increased percentage of cells with multiple constrictions, and a stalkless phenotype. These defects are also seen in the ctrA temperature sensitive strain grown under permissive conditions. Complementation of YB3558 with a wild-type ctrA gene under native control (YB3559) restores cell morphology to that of wild-type. Figure 3 Lectin binding of wild-type CB15, YB3558 and YB3559. Wild-type, YB3558
and YB3559 cells were treated with FITC-conjugated WGA lectin and imaged as described in the Methods. WGA lectin binds to holdfast and is seen as a fluorescent focus when imaged (example indicated with white arrow, WT panel). Wild-type cells display holdfast at the tips of stalks, while the YB3558 mutant produces no holdfast. Complementation Erismodegib order of YB3558 with a ctrA gene under native control (YB3559) restores holdfast synthesis. YB3558 demonstrated similar phage resistance to ΦCbK as podJ in a phage sensitivity assay. When serial NSC23766 clinical trial Dilutions of cells were mixed with phage stock and spotted on PYE plates (Figure 4), cell growth in lower
dilutions was slightly less dense than that of the fully resistant podJ mutant. However, relative to wild-type cells, YB3558 exhibited significant phage resistance, allowing survival at the lower dilutions of phage. Finally, YB3558 grew more slowly than wild-type with a doubling time of 123 minutes as compared to 97 minutes (Figure 5). Figure 4 Phage resistance Tangeritin of YB3558 and YB3559. Resistance to the Caulobacter phage ΦCbK was assayed as described in the Methods. Dilutions of cells were mixed with phage stock and spotted onto PYE plates. CB15 is sensitive to the phage, ΔpodJ is resistant, and YB3558 shows virtually the same phage resistance as ΔpodJ. Complementation with ctrA under native control (YB3559) decreases phage resistance to nearly wild-type levels. Figure 5 Growth rate of YB3558 and YB3559. Growth curves of CB15 (black diamonds), YB3558 (open squares) and YB3559 (black squares). YB3558 shows slower growth than wild-type. Complementation with ctrA under native control (YB3559) restores wild-type growth.