Figure 1.

Strategy for the detection of HOR signs. Transposition of the Tn5 transposon to DNA molecules of an AS-containing fosmid clone was induced, and two clones carrying Tn5 at different positions were selected. Each clone was sequenced using two primers that annealed to Tn5 and oriented outward. The sequence reads (∼900 bp, including the tail region of a low reliability) were combined, and a longer sequence (∼1800 bp) was obtained. These sequences were compared between the two clones by the dot-matrix analysis. When a line spanning more than two basic units was found, it was regarded as a sign of HOR.