Figure.

Pulsed-field gel electrophoresis of intact genomic DNA of Vibrio cholerae isolates and circular representation of the genome of V. cholerae O1 El Tor TSY216, consisting of 3 chromosomes. The preparation of genomic DNA embedded in agarose gels and the protocol for pulsed-field gel electrophoresis have been described previously (5). Arrows indicate DNA bands that correspond to the chromosomes. Lanes: 1, N16961 reference strain carrying Ch1 (2.96 Mb) and Ch2 (1.07 Mb) (2); 2, TSY216; 3, TSY241; 4, TSY421. The first and second outermost 2 circles of each schematic chromosome show the COGs, functional categories of the coding regions of TSY216, in the clockwise and anticlockwise directions, respectively. The third and fourth outermost circles of each schematic chromosome show the coding sequence-assigned (blue) and coding sequences-unassigned (red) functions of the products, respectively. The third and fourth circles show the GC content of the TSY216 sequence and the percent G+C deviation according to the strand, respectively. Ch1, chromosome 1; Ch2, chromosome 2; COGs, clusters of orthologous groups of proteins; Rep.3, novel replicon.