Effects of cytochaslasin B and colcemide on myogenic cultures.
Muscle cultures treated with cytochalasin B yield mono- and oligonucleated cells of two kinds: (i) arborized, replicating precursor myogenic cells and fibroblasts; and (ii) round, post-mitotic, terminally differentiating myoblasts and myotubes. The arborized cells do not bind fluorescein-labeled antibody against myosin, do not contract rhythmically, and do not display hexagonally stacked thick and thin filaments. The round, mono-nucleated myoblasts and round, oligonucleated myotubes bind the fluorescein-labeled antibody against myosin, contract rhythmically, and display clusters of hexagonally-stacked thick and thin filaments. When cytochalasin B is removed and replaced by colcemide, the arborized cells, but not the post-mitotic muscle cells, acquire a radial symmetry and are induced to assemble massive, meandering cables that may occupy over 25% of the cell volume. These tortuous calbes are positively birefringent and consist exclusively of enormous numbers of 100-A, intermediate-sized filaments.
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002467:Cell Nucleus / Q000648:ultrastructure; D002642:Chick Embryo; D003078:Colchicine / Q000494:pharmacology*; D046508:Culture Techniques; D003571:Cytochalasin B / Q000494:pharmacology*; D009132:Muscles / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D009210:Myofibrils / Q000648:ultrastructure
D003571:Cytochalasin B; D003078:Colchicine