Fig. 5. Many metaphases in Topo II-depleted cells have an unusual phenotype in which one or more chromosome arm(s) becomes highly elongated and stretches towards the spindle pole. (A) Control RNAi-treated normal metaphase cell. (B) Topo II RNAi-treated metaphase cell with a highly elongated chromosome arm extending to one spindle pole. (C) Topo II RNAi-treated metaphase cell with J-shaped chromosome arms extending to spindle poles. (D) Statistical analysis of the protruding arm phenotype. (A-C) DAPI staining for DNA; (A'-C') anti-tubulin shows the mitotic spindle; (A"-C") staining for Cid/CENP-A shows the position of kinetochores; (A'"-C'") merged images (DAPI is blue, tubulin is red, Cid is green). Scale bar: 5 µm.