Mitosis in Beating Cardiac Muscle Cells from Newt Embryos In Vitro

Publisher Website
Google Scholar
Abstract
Cardiac muscle cells from newt embryos were cultured at relatively low cell density. Within 10 days in culture, 2 cell types (spindle and flat type) were distinguished both among beating and non-beating cells. Mitosis in single-beating cells was frequently observed in spindle and flat cells. Some cells maintained almost constant contractile activities throughout the mitotic stages, while the others transiently stopped beating during mitosis, which agrees well with results in chick embryos. Ultra-thin section shows the presence of myofibril structure in a dividing cell, as shown in newborn rats, chick embryos and adult newts. As a consequence of mitosis, 3 types (spindle, flat and mixed type) of beating colonies developed after 3-4 wk in culture. Cell proliferation was accompanied by pulsation and could be directly pursued until the 4th division, suggesting that differentiated myocardiac cells with myofibrils proliferate by their mitoses in vivo, maintaining rhythmic contraction.
Keywords