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ically isolated from continents. Figure 2 shows the IDSA1 chromosome with the functional categories of each gene. Its GC skew values corresponded to the tendency of gene orien-tation, as typically seen in S. aureus genomes23). The positions of mobile genetic elements, including The first outermost circle is scale in kilobase pairs. The second and third circles show open reading frames on the plus and minus strands, respectively. The fourth circle shows G+C contents, with purple indicating higher than average; and the fifth circle shows GC-skew, with pink indicating higher than average. The positions of mobile genetic elements, including SCCmec, prophages, transposons and other genomic islands, are indicated outside the first circle (see also Figure 3).152Table 4　Complete genome statistics of IDSA1 and TW20strainLength of sequence (bp)G+C contents (%) No. of protein coding regionsNo. of rRNAsFigure 2　Functional genomic organization of the chromosome of Staphylococcus aureus strain IDSA1No. of tRNAsNo. of prophagesIDSA1309621332.8129716556055S16S23STW20304321032.782941655603prophages, transposons, SCC and other genomic islands24), are highlighted. Figure 3 is a global genome rearrangement map between IDSA1 and TW20 that allows comprehensive visualization of insertions and deletions. The red lines show the start positions of common coding sequences (CDS) on both chromosomes. The extraordinarily large CDS seem like gaps in principle, despite the two genomes sharing the CDS. The gap appearing approximately at the 1.5 Mbp position is such an example, corresponding to ebh genes24), which code for proteins of over 10,000 amino-acids. The mobile genetic elements are highlighted in Figures 2 and 3, and the positions of drug resistance genes are indicated in Figure 3. Many drug resistance genes were found to be accompanied by mobile genetic elements. For example, the blaZ gene, which encodes the β-lactam degrading enzyme BlaZ, was