Fig. 2. Association and intranuclear organization of chromosomal tetO inserts in yeast nuclei. (A) In a diploid strain, two tetO repeats associate in the presence of TetR molecules and form a single signal in most cells, irrespective of their chromosomal positions. (B) In hydroxyurea-arrested nuclei, tetO associations are reduced and two separate GFP signals are seen in most nuclei. (C-E) Association behaviour of tetO repeats during anaphase of diploid cells. (C) Centromerenear tetO repeats (CEN/CEN) remain mostly associated and form a single GFP spot near the two spindle poles. (D) Telomeric regions (TEL/TEL) also remain mostly associated and appear as a single signal in the two daughter nuclei. (E) Ectopic tetO inserts (one near the centromere, the other near the telomere: trans-CEN/TEL), which are frequently associated in interphase, are mostly separate in anaphase cells and appear as two GFP signals in both daughter nuclei. (F,G) Recruitment of the telomere-near tetO repeat to the centromeric pole in trans-CEN/TEL nuclei. FISH with probes for the centromere-near (F, probe 1) and telomere-near (G, probe 2) tetO insertion site in wildtype (left) and the trans-CEN/TEL strain (right). Centromeres are always close to the SPB. In the wildtype, both telomeres are far from the SPB, whereas in the trans-CEN/TEL strain, one telomere is usually close to the SPB (see also Fig. 5). green, GFP; red, immunostained spindle and SPBs; orange, FISH signals. Bar, 2 µm.