FIG. 2.

Colony morphology of M. xanthus wild-type and cglB motility mutant strains. (a) Wild-type (DK1622); (b) ASX1 (ΔcglB S⁺); (c) ASX2 (ΔcglB ΔpilA) and (d) ASX21 (ASX1 containing p343B4). Note the absence of individual and small groups of cells at the perimeter of the ΔcglB strain ASX1. Genetically complemented strain ASX21 (ASX1 containing p343B4) exhibited a colony morphology that resembled that of DK1622 (wild type). All swarming was abolished in the A⁻ S⁻ double-deletion mutant ASX2. For strain construction, see Materials and Methods. Bars indicate 100 μm.