Fig. 6. Expression of ubiquitin is upregulated in dividing cardiomyocytes. Cultured cardiomyocytes were stained with antibodies to sarcomeric -actinin (A,D,G) together with antibodies against ubiquitin (B,E,H) and against tubulin (C,F,I) to identify the stage of cell division. Single confocal section reveal that while interphase cardiomyocytes display only little signal for ubiquitin (B); a big increase in the signal for ubiquitin can be detected in cardiomyocytes in metaphase (E) as well as in cytokinesis (H). There is no clear-cut colocalization between -actinin and ubiquitin. Bar represents 10 µm.