Figure 3

Pan-genome calculations of the conserved core, predicted new genes and pan-genome size of thirteen B. burgdorferi s.s. isolates. (A) Conserved genes (core genome) plotted as a function of the number n of sequenced genomes (x-axis). For each n, colored data point represents values of the number of conserved genes obtained for all possible combinations of compared genomes. The black line shows the exponential decay model based on the median value for conserved genes when increasing numbers of genomes are compared. (B) Plot showing decreasing numbers of discovered new genes with increasing number of genomes compared. The black line shows the exponential decay model based on the median value for new genes when increasing numbers of genomes are compared. (C) Pan-genome of the B. burgdorferi species. The extrapolated curve plateaus at a value of about 1500 with 13 genome sequences, and as a consequence, B. burgdorferi s.s. has a closed pan-genome.