FIG. 4.

Subcellular localization of DnaA-EYFP and LacI-ECFP foci. (A) The positions of DnaA-EYFP and LacI-ECFP (ori1) foci in each cell. One hundred cells of the dnaA-eyfp lacI-ecfp/lacO (ori1) strain were examined. The ordinate represents the distance of the focus center as measured from a cell pole. Green square, DnaA-EYFP focus point in cells with a single DnaA-EYFP focus or the DnaA-EYFP focus point closest to the chosen cell pole in cells that exhibited more than one DnaA-EYFP focus point; green triangle, the second DnaA-EYFP focus area; green circle, the third DnaA-EYFP focus area; magenta square, ori1 focus point in cells with a single ori1 focus or the ori1 focus point closest to the chosen cell pole in cells that exhibited more than one ori1 focus; magenta triangle, the second ori1 focus area; magenta circle, the third ori1 focus area; magenta diamond, the fourth ori1 focus area. Cells with no focus are plotted as crosses on the abscissa. The straight line indicates cell length. (B) Classification according to cellular focus number. Cells analyzed in panel A were grouped according to the number of foci as shown. Proportions of cells and a graph of average cell length with standard deviation in each category are indicated. Pictures of representative cells in five categories are shown. DnaA-EYFP is presented by black and white and by colors. In the merged pictures, LacI-ECFP and DnaA-EYFP are shown by magenta and green, respectively. Fluorescence intensity of DnaA-EYFP is shown at the bottom. The intensity scale is shown at the right both by a linear gradation of black and white and by colors.