Functional Aurora-B kinase is expressed in EnM MKs. (A) Deconvolution images of a series of murine polyploid MKs showing localization of Aurora-B kinase (green) to centromeres. DNA is blue. Cells shown are in prometaphase with chromosomes not yet completely aligned, metaphase with chromosomal alignment evident to several plates, and anaphase. Note centromere localization of Aurora-B kinase in up through metaphase with indistinct localization in anaphase. (B) Histone H3 is phosphorylated on Ser10 in EnM murine MKs. Phospho-histone H3 is shown in green and tubulin in red; left image shows a cell with chromosomal alignment suggesting metaphase, whereas the very large cell on the right appears to be in early anaphase with chromosomal separation. (C) Localization of Aurora-B kinase (green) to centromeres does not require intact kinase activity. Purified mouse MKs were incubated for 2 hours with 5 μM ZM447439 prior to fixation and immunostaining for Aurora-B kinase (green) and phospho-histone H3 (red). Phosphorylation of histone H3 is absent due to inhibition of aurora kinase.