Overexpression of aurora B kinase does not phosphorylate histone H3 in interphase NRK cells. NRK cells overexpressing aurora B-GFP was stained with antibodies that specifically recognised histone H3 phosphorylated at Ser10 and then examined the expression of aurora B-GFP (a) and phosphorylation of histone H3 (c) by confocal laser microscopy. Corresponding phase and merged images (green; aurora B-GFP, red; phosphorylated histone H3) are shown in panels b and d, respectively. Although a fraction of aurora B-GFP is accumulated in the nucleus in a late telophase cell overexpressing aurora B-GFP, (arrows), phosphorylated histone H3 was not detected in the cell (c, d). Phosphorylated histone H3 was observed in a neighbouring prophase cell (arrowheads). Bar, 10 μm.