Figure 3

Gene acquisitions and losses. The method described here (see Figure 1) only identifies losses of genes (in genome A) that have been conserved in the two other lineages considered (genomes B and C; in green). If recent acquisitions (in black) are deleted shortly after their integration in the genome, what we observe is a high number of acquisitions compared with losses. This, rather than an increase in genome size, may explain the results presented in Figure 2.