TABLE 4.
Effect of iteron number on coresident plasmid segregation patterns in the absence and presence of excess RepC
| pRAS1 plasmid | Coresident plasmidsa |
% colonies with resistance to the following antibiotic(s): |
Direction and strength of segregation biasb | |||
|---|---|---|---|---|---|---|
| pRAS3.1.35.Km + pBAD28 | pRAS3.1.35.Km + pBAD28-RepC | Tet only | Km only | Tet and Km | ||
| pRAS3.1.35.Tet | • | 53 ± 11 | 21 ± 6 | 28 ± 10 | Tet > Km | |
| • | 55 ± 8 | 17 ± 1 | 29 ± 5 | Tet > Km | ||
| pRAS3.1 | • | 91 ± 6 | 1 ± 1 | 7 ± 5 | 4 iterons >>> 3 iterons | |
| • | 88 ± 4 | 7 ± 3 | 6 ± 0 | 4 iterons >>> 3 iterons | ||
| pRAS3.1.55.Tet | • | 79 ± 3 | 6 ± 3 | 14 ± 6 | 5 iterons ≫ 3 iterons | |
| • | 67 ± 2 | 16 ± 2 | 21 ± 1 | 5 iterons ≫ 3 iterons | ||
| pRAS3.1.75.Tet | • | 63 ± 14 | 25 ± 13 | 15 ± 2 | 7 iterons > 3 iterons | |
| • | 63 ± 11 | 26 ± 13 | 13 ± 4 | 7 iterons > 3 iterons | ||
a
The small black circles indicate the two plasmids in the cell in addition to the pRAS3 plasmid used in each experiment. All plasmids were completely stable in the absence of antibiotics for the duration of the assay.
b
Direction and strength of segregation bias as a result of iteron number in the absence or presence of additional RepC. Arrowheads indicate the direction of plasmid displacement, and the number of arrowheads is an indication of the strength of displacement.