The interaction between Bqt4 and Rap1 is essential for telomere clustering. (A) Diagram of Bqt4 constructs. (B) Yeast two-hybrid assay between Bqt4 constructs and the full-length Rap1. AD and BD indicate the constructs based on the pGADT7 and pGBKT7 plasmids, respectively (see Materials and methods). (C) NE localization of GFP–Bqt4-dN in vegetative bqt4Δ cells. (D) NE localization of GFP–Bqt4-dN and scattered telomeres (Taz1-mCherry) in the horsetail nucleus in a bqt4Δ cell. (E and F) Localization of Rap1-GFP–Bqt4-dN in vegetative cells (E) and in meiotic horsetail (F) in bqt4Δ. (G) Percentages of nuclei bearing a single cluster of telomeres in each strain as indicated. Strains observed are row 1, CRLs25 (n = 103); row 2, CRLs33 (n = 128); row 3, CRLx02 (n = 86); row 4, CRLx01 (n = 113); row 5, CRLx03 (n = 57); and row 6, CRLx04 (n = 74). Bars, 10 µm.