Fig. 1

Conserved core genes and the pan-genome for 114 P. multocida. The sizes of the pan-genome and core genes are plotted as a function of the number (n) of strains sequentially added. On the above curve, increasing number of pan-genomes with an extrapolated curve increases the number of genes, showing an open pan-genome of P. multocida. On the blew curve, the core genes show the exponential decay model based on the median value for conserved genes when increasing numbers of genomes are compared