The chromosomal passengers, INCENP and survivin, are present at centromeres in EnM MKs. (A) RT-PCR showing expression of INCENP and survivin in polyploid murine MKs. RNA was isolated from gradient-purified MKs or BaF3/Mpl cells as a diploid control. Lanes 1, MKs; lanes 2, BaF3/Mpl; lanes 3, negative control. (B) Aurora-B kinase is present and functional in human MKs. Aurora-B kinase is shown in green and phospho-histone H3 is shown in red. Note the localization to midzone structures in the two rightmost images shown in anaphase. (C-D) INCENP and survivin (green) are present and properly localized in human MKs. Tubulin is shown in red, and DNA is blue. Note the localization to centromeres in the leftmost 2 images of metaphase cells, then midzone structures in the next 2 images shown in anaphase.