Abstract
It has previously been shown that following the ablation of nonmuscle myosin heavy chain II (NMHC II), developing cardiac myocytes exhibit defects in cytokinesis. Our recent data from the analysis of tissue sections of mouse hearts lacking nonmuscle myosin II-B and II-C at embryonic day 14 (E14) reveal that in addition to its known role in cytokinesis, nonmuscle myosin II is also involved in karyokinesis. Additionally, we show that cardiac myocytes lacking II-B and II-C exhibit elevated levels of p21, a known inhibitor of apoptosis.
