FIG. 1.

(A) Schematic representation of the CTX prophage (∼7 kb) and surrounding sequences in V. cholerae. The open reading frames (ORFs) are shown as arrows. Black arrowheads, locations of the PCR primers listed in Table 2; vertical lines, restriction enzyme sites; horizontal bars, positions of the three DNA probes used for hybridization. (B) Schematic representation of the VPI prophage (∼40 kb) in V. cholerae. The ORFs and gene clusters are shown as dotted arrows. Black arrowheads, locations of the PCR primers listed in Table 2; horizontal bars, locations of the four DNA probes used for hybridization.