STB plasmid localization at pachytene with respect to nuclear periphery in ndj1Δ and csm4Δ strains. (A and B) The nearest distances of individual plasmid foci from the edge of the DAPI staining zone were measured to separate the foci into two groups: “internal” (at the edge of the DAPI zone or within it) and “external” (outside the DAPI boundary). (C) The external group of foci was subdivided into three types, based on the extent of their separation from the boundary. (D and E) Plasmid distances were measured from the nuclear envelope (outlined by Nup49-mCherry) along the diameter of circular cross sections of the nucleus (Meister et al., 2010). They were distributed into three zones (1–3) of equal area by placing the zone 1–2 boundary at √(2/3 × R) and the zone 2–3 boundary at √(1/3 × R), where R = the radius of the circle. The dashed line in E marks the probability of the random occurrence (33.3%) of a plasmid focus within a zone. The experimental strains harbored fluorescence-tagged CEN VII (TetR-Td-Tomato-[TetO]₂₂₄) (red dot). Leptotene/zygotene and pachytene stages were distinguished by two red dots (unpaired homologues; cohesed sisters) and one red dot (paired homologues), respectively. The data in all panels were each obtained by analyzing ∼100 plasmid foci. Bars, 2 µm.