Fig. 1

Number of genes as a function of the number of sequenced Burkholderia genomes. (a) The pan-genome size, that is, the number of all genes in sequenced strains. The number of new genes decreases with each new genome n at the rate N(n)=2557n^−0,56 confirming that the pan-genome is open. As the numbers of genomes n→∞, the pan-genome size converges to 88,080 and the core-genome size converges to 457 genes. (b) The core-genome size, that is, the number of common genes in sequenced strains. The core-genome for a single strain (n=1) is defined as the number of genes in the strain