A duplication between the CR and the N gene caused by two OL-like structures. (A) H-strand synthesis is initiated at an origin for light-strand replication (OH). (B) L-strand synthesis is initiated at OL-like structure 1 when the replication fork reaches approximately two thirds of the genomic distance from the CR. (C) H-strand synthesis is terminated, and OL-like structure 2 initiates a second round of L-strand synthesis. (D) Both L-strand synthesis events are terminated at the WANCY region. (E) Connection of the 5’ end of Nascent L-strand 1 to the 3’ end of Nascent L-strand 2 and of the 3’ end of Nascent L-strand 1 to the 5’ end of Nascent L-strand 2. (F) The genes between the CR and N are, thus, duplicated.