Characterizing cellular and subcellular localization patterns in large populations (at least 10,000 time points).

<p>A: Left: Typical cellular localization patterns and their relative frequency of occurrence (in <i>E. coli</i>, see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006582#pgen.1006582.s004" target="_blank">S4 Fig</a> for corresponding <i>B. subtilis</i> data) are shown for all cells regardless of length. Extremely rare localization patterns (4+ foci) are not shown. Right: Relative frequency of the same typical cellular localization patterns as a function of cell length (age). Dashed red line represents mean cell length both at re-initiation and division. B: Multiple focus cellular localization patterns are distinguishable automatically based on inter-focus separations. Scatter plot shows relative focus separation as a function of cell length for multiple focus cells. Two well resolved populations are observed. Pairs of foci whose separation falls into the lower population are counted as individual members of a sister fork pair, whereas all other foci are each inferred to represent a co-localized replication fork pair. Dashed red line represents mean cell length at re-initiation and division. Example shown is for DnaN-YPet foci in <i>E. coli</i>. See also <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006582#pgen.1006582.s004" target="_blank">S4 Fig</a> for corresponding <i>B. subtilis</i> data. C: Pie charts showing the fraction of sister replication fork pairs that are co-localized (replisomes have diffraction-limited separation) versus resolvable (each replisome appears as a member of a narrowly separated focus pair). In both organisms, replication fork pairs remain co-localized roughly 80% of the time, consistent with a factory-like model.