Fig. 3. Sister kinetochores exhibit asymmetric Bub1/BubR1 staining. Projections of deconvoluted image stacks showing DLD-1 cells stained with 4B12 (anti-Bub1, red), SBR1.1 (anti-BubR1, green) and Hoechst (blue). Scale bars represent 5µm. (A) Merged red/green image of an untreated cell showing that one kinetochore within a pair often appears green while the other appears orange/yellow, indicative of asymmetric Bub1/BubR1 staining. The arrowheads identify four clear examples. (B) A taxol-treated cell, showing splayed-out chromosomes due to microtubule stabilisation, also exhibits asymmetric Bub1/BubR1 staining. (C) A nocodazole-treated cell, showing collapsed chromosomes owing to microtubule depolymerisation, exhibits reduced Bub1/BubR1 asymmetry: most of the kinetochores appear orange/yellow.