Fig. 5: A- or S-motility mutations affect predation efficiency.
a Predation over time at the forefront visualized with semantically segmented images containing the masks for M. xanthus (green) and E. coli (white). Two zones were defined: (i) where no invasion occurred (orange area) and (ii) where M. xanthus cells invaded E. coli (Invaded zone). Scalebars = 100 µm. b Total raw fluorescence signal from E. coli cells over time. Orange and blue boxed areas highlight the safe zone, where no predation occurred and the predation zone, where active predation is occurring, respectively. Scalebars = 100 µm. c Ratio of the last to the first image of the E. coli HU-mCherry raw fluorescence. Black and gray dashed lines represent a visual guide to the front of swarm and scout cell populations, respectively. Colorbar: blue represents regions where E. coli cells were killed. d Same as c but for M. xanthus OM-sfGFP. The right panel represents an overlay of the raw HU-mCherry images from E. coli and OM-sfGFP from M. xanthus corresponding to the ROI represented by a purple square in the left image and in panel c. Colorbar: red represents regions with an enrichment in M. xanthus cells in the last time point, whereas blue regions represent depletion of M. xanthus cells. e–g Quantification of the total fluorescence signal from E. coli cells over time in the safe and predation zones for wild type (e), S-motile (A-S+) (f), and A-motile (A+S-) (g) predators. h Box plot summary of total fluorescence decay time from E. coli cells in the safe and predation zones (orange and blue shaded boxes, respectively) from six experimental replicates for the wild-type and four replicates for each mutant strains. Boxes show the median and the interquartile range, while whiskers represent the minimum and maximum values in the datasets. The statistics were calculated using a two-sided t-test. p-values were as follows: A-S+ vs A+S- = 1.10−1. A-S+ vs wild type = 3 × 10−2. A+S- vs wild type = 3 × 10−3.
