Movement of individual STB plasmid foci in wild-type, csm4Δ, and ndj1Δ strains. The traces from three representative cells each illustrate the excursions of individual plasmid foci (denoted by different colors) over a 1-min period in the wild-type (A), csm4Δ (B), and ndj1Δ (C) strains (Fig. 5, Fig. 6, and Fig. S3; and Videos 2 and 4). The plasmid foci were visualized at 4 h (wild type) and at 7 h (mutants) after transfer to sporulation medium. The nuclear periphery (broken lines) is an approximate representation deduced from a single frame of each 60-frame movie, based on background nuclear fluorescence from GFP-LacI. For comparison, the paths traversed by unpaired IVR TELs over a 1-min span are depicted in D–F (Videos 1 and 3). As the pertinent nuclei images were not available, the nuclear outlines in D–F were arbitrarily chosen from the plasmid movies representing the relevant genetic backgrounds. n = number of plasmid foci in a nucleus. Bar, 2 µm.