FIG 3.

Model of the integration of TLC (2) and RS1 (3a) or CTX (3b) into the attB site of the replication terminus of chromosome I and orientation of the genomic region commonly found in 7th pandemic El Tor strains (4). (5) Superinfection of RS1 or excess expression of the RstC antirepressor in a cell possessing genomic CTXϕ and RS1 islands can result in excision of CTXϕ. (6) Reintegration of CTXϕ may result in rearrangement, though reorganization between the genomes in panels 4 and 6 is unclear.