The Artemis comparison tool analysis of genomic island sequences. All genomic islands tested share extensive sequence homology, and the genes are arranged mostly in the same order. Red vertical lines correspond to regions that are highly homologous, mainly in the putative replication and type IV secretion system modules. Pink vertical lines (right end) correspond to regions with lower sequence homologies, in particular for the putative integration module. Blue vertical lines depict a region containing the transposon (Tn)10, whose orientation is reversed between ICEHin1056 and ICEHpaT3T1. Arrows on top and bottom delimit the functional regions whose order is well conserved in all seven genomic islands. ICE, integrative and conjugative element.