Abundance and co-occurrence of extracellular capsules increase environmental breadth: Implications for the emergence of pathogens
A. Percentage of genomes with none, one or more capsular systems, irrespective of capsule groups. The number of genomes is indicated on top of the bars. B. Box-plots of the distribution of genome size in respect to the number of capsule systems identified in the genome. Y-axis is in log scale. Each point reflects one individual genome. The boxes span from the first to third quartile and the central line indicates the median. The length of the vertical line extends from the first and third quartile to the lowest and highest data points that are no more than 1.5 times away the interquartile range. Genome size was calculated as the sum of all chromosome and plasmid sizes, and was log10-transformed prior to statistical analysis. Asterisks indicate significant differences in median genome size across groups, Tukey post hoc test. *** P < 0.0001, ** P < 0.01. C. Histogram of the number of capsule groups per genome (among genomes encoding at least one capsule). The number of genomes is indicated on top of the bars. D. Network of co-occurrences of capsule groups. The size of the nodes is proportional to the number of genomes encoding the capsule group. The width of the links is proportional to the total number of co-occurrences. Red (-) and green (+) edges indicate significant negative and positive associations, respectively. We indicate three types of significant results. Main results are for the test of significant dependent evolution between capsule groups. These pass two tests: a test of independence on a contingency table (χ2) and a test of phylogenetic dependence accounting for phylogenetic uncertainty (see Methods). *** P < 0.0001, ** P < 0.01, * P < 0.05.