FIG. 3.

Bub3p interacts with the central core chromatin of fission yeast cen1. (A) Diagrammatic representation of fission yeast cen1. The central domain includes the cnt and imr and is flanked by heterochromatic otr. (B) Arrested nda3 Bub3-GFP cells were fixed and labeled with anti-GFP antibodies and with 4′,6′-diamidino-2-phenylindole staining of the condensed DNA. Bar, 10 μm. (C) Bub1/3-GFP ChIPs from nda3 cells that had been incubated at 18°C to induce a checkpoint-dependent mitotic arrest. The cnt and imr of cen1 were enriched in the anti-GFP (Bub3 and Bub1) immunoprecipitations from mitotically arrested cells but were barely detectable in cycling cells (32°C). fbp is a noncentromeric, euchromatic negative control.