Yeast anaphase tubes contain DNA bridges bound by Dpb11 that delay nuclear division. (A) Dpb11 anaphase bridges are contained within an anaphase tube. Cells (ML533) expressing Dpb11-YFP, CFP-Nup49 (pWJ1323), and NLS-RFP (pKW1219) were grown in SC-His-Leu medium with 100 µg/ml adenine. (B) Dpb11 is bound to DNA in anaphase bridges. Cells (ML628) expressing Dpb11-YFP, Spc110-CFP, and NLS-RFP were analyzed by time-lapse microscopy. Resolution of the Dpb11 bridge before the NLS-RFP marker was observed in 43% of anaphases examined (n = 37). (C) Hoechst-negative anaphase bridges contain DNA. Cells (VS28) were grown for 3 h in SC+Ade medium with 20 µM EdU before fixation and Hoechst staining. (D) Hoechst-negative EdU-positive anaphase bridges are induced by hydroxyurea. Cells (VS28) were labeled with EdU for 3 h before treatment with 20 mM hydroxyurea (HU) for 1 h and subsequently fixed and stained with Hoechst. Error bars represent 95% confidence intervals. (E) Resolution of Dpb11 bridges is coincidental with relaxation of the mitotic spindle. The distance between the SPBs (Spc110-CFP) in B was measured in three dimensions (3D) and plotted as a function of time. (F) Relationship between spindle length and Dpb11 bridges. Cells (VS3-7A) expressing Dpb11-YFP and Spc110-CFP (SPB) were imaged. The distance between the SPBs was measured in 3D and the cells scored for Dpb11 bridges. The median spindle length observed for Dpb11 bridge–negative and –positive cells was 4.7 µm and 7.0 µm, respectively. Only Hoechst-negative Dpb11 bridges were counted.