Fig. 4: Visual description of the RPSL simulation framework and simulation results.

a Two strains with identical (compatible) traA alleles are spatially mixed. b Striped cells are aggressors containing sitA alleles that are detrimental to susceptibles (plain cells). c Susceptible myxobacteria (blue cells) may have different traA alleles that could be compatible or partially compatible with traA alleles of the aggressors. d Among the susceptible myxobacteria, a small group of cells can gain mutations in traA alleles, converting them into traA minority (light blue cells). The other susceptible cells accordingly become the traA majority. traA majority and traA minority may have partially compatible or incompatible TraA receptors. Likewise, the aggressor strain can be divided into the traA majority and minority (striped yellow cells). e Two strains (Str1, Str2) with compatible traA alleles with different sitAI repertoire. In each homogeneous group, the control group (C1, C2) was postulated which has the identical spatial distribution as the traA-minor groups in the subsequent simulations. The population size of the control group was traced to derive the proportional fitness which is used to investigate whether a mutation in the traA allele confers fitness advantage (r–u). HC: homogeneous compatible. f Same as (e) for two homogeneous strains with partially compatible traA alleles. HP: homogeneous partial. g Two major groups (M1, M2) have compatible traA alleles, while the minor groups (m1, m2) have partially compatible traA alleles with their cognate major groups. Two minor groups are incompatible for OME. MCmP: major compatible, minor partial. h While major groups have compatible traA alleles, minor groups cannot form OME with other groups. MCmI: major compatible, minor incompatible. i Same as (g) except that two traA-major groups have partially compatible traA alleles. MPmP: major partial, minor partial. j Same as (h) except that two traA-major groups have partially compatible traA alleles. MPmI: major partial, minor incompatible. k Triple bars between groups imply that both groups have compatible traA alleles. A thick dashed line represents partial compatibility between traA alleles of the two groups, while traA alleles within each group are homogeneous. l A freeloader strain (rock) and a susceptible strain (paper) with compatible traA alleles competed in the simulation arena. The comparison of proportional fitness indicates that susceptibles outcompete freeloaders given that there is no traA-minor group. The upper right asterisk indicates that the two datasets are significantly different (Wilcoxon signed-rank test). m Same as (l) for partially compatible strains. n, o Same as (l, m) for susceptibles and aggressors. p, q Same as (l, m) for freeloaders and aggressors. r traA-minor group of susceptibles (blue circles) exhibits significantly higher proportional fitness compared with the parental traA group (control, blue squares) that has identical traA alleles with the traA majority of the aggressors (MCmP). The fitness of the susceptible traA minority is significantly higher if traA mutation results in incompatibility with the parental population (blue dashed arrow). Conversely, the opposite trend is identified for traA minority of aggressors (red dashed arrow). The integer of each marker represents the rank within the dataset based on statistical significance. In this panel, the parental traA group of susceptibles has significantly lower fitness than other groups and is thus assigned rank 4. However, altering the initial proportion of the traA minority (0.1 in this simulation) may influence the relative fitness dominance between the groups. s–u Same as (r) for MCmI, MPmP, and MPmI, respectively. The asterisks imply that all groups within each panel are significantly different. v Explanations of the diagrams used in this figure.