Fig. 2

The genomes \({\mathcal {G}}= ([B\,\, A\,\, B],[1\,\, 3])\) and \({\mathcal {H}}= ([C\,\, D\,\, A],[2\,\, 2])\) combined to form the genome \({\mathcal {K}}= ([B\,\, A\,\, B\,\, C\,\, D\,\, A],[1\,\, 3\,\, 3\,\, 2\,\, 2])\). Note that, an intergenic region with size 3 was created during the combination. Besides, the genome \({\mathcal {K}}\) contains the genomes \({\mathcal {G}}\) (\({\mathcal {G}}= {\mathcal {K}}^{1,3}\)) and \({\mathcal {H}}\) (\({\mathcal {H}}= {\mathcal {K}}^{4,6}\))