Figure 3.
The icmA− phenotype. (A) Wild-type, icmA−, and icmA−/+ cells under 100× Nomarski optics. Bar, 10 μm. (B) Wild-type or icmA− cells were washed free of bacteria and plated on 2% agar plates at 2.1 × 105 (a), 8.6 × 105 (b), or 1.7 × 106 (c) cells/cm2, and they were allowed to develop for 3 days. Wild-type cells all formed normal fruiting bodies. icmA− cells formed a few sparse clumps of cells that failed to develop further. The top panel in each frame illustrates the morphology of sparse clumps; the bottom panel illustrates typical fields of very loosely clumped cells that fail to develop further. (C) Wild-type fruiting bodies at different developmental stages. Cells were grown on plates with bacteria, harvested, washed free of bacteria, and plated on 2% agar plates at 4.2 × 105 cells/cm2. (D) icmA− cells were inoculated onto heavy streaks of E. coli on 2% agar plates and incubated for 3 days. Bars, 100 μm.