FIGURE 3.

Mechanism of ISEcp1–mediated homologous recombination depicted by analysis of Nanopore long-reads. ISEcp1 was found to exhibit a size of 530 bp in pSa42-91k. A fragment of ISEcp1 was cloned into pBackZero-T vector (depicted in black). Such fragment exhibited sequence homology with ISEcp1 from pSa42-91k (depicted in gray). A 21 bp and 168 bp region were located at each terminal. (A) When the homologous recombination process started from the left, various sizes of ISEcp1 linked with the 21 bp sequence were observed in Nanopore long reads; oppositely oriented terminal side of a 509 bp constant size could be detected in another ISEcp1. (B) Homologous recombination began in the opposite direction, Nanopore long reads were also found to contain various sizes of ISEcp1 at 341 bp, which were connected to a 168 bp fragment in the original ISEcp1, whereas another part of 362 bp in the original ISEcp1 whose size was stable and not variable was located in the other end.