title: Differentiation of quail myoblasts transformed with a temperature sensitive mutant of Rous sarcoma virus. II. Relationship of myoblast fusion with calcium and temperature.
abstract: The effects of calcium and temperature on fusion of quail embryonic myoblasts were examined using cells transformed with a temperature-sensitive mutant of Rous sarcoma virus (ts-RSV). The transformed quail myoblasts (QM-RSV) fused to form myotubes at 41 degrees C, the non-permissive temperature, but not at 35.5 degrees C, the permissive temperature. On incubation at 41 degrees C, a period of more than 10 hr was needed for the myoblasts to become fusion-competent, but calcium was not needed for development of fusion-competence. Once the cells had become competent, fusion proceeded even at 35.5 degrees C. These results suggest that the src gene product expressed at 35.5 degrees C may control the fusion of cells in the competent stage by inactivating a component(s) that is associated with fusion-competence. However, fusion of even myoblasts in the competent stage was blocked in calcium-deficient medium, suggesting that calcium is essential for the fusion, probably at a step immediately before membrane union. Unlike fusion, other biochemical processes of differentiation proceeded even in calcium-deficient medium, indicating a distinction of fusion from these other processes during myoblast differentiation.
authors.affiliation: Institute of Molecular and Cellular Biology for Pharmaceutical Sciences, Kyoto Pharmaceutical University, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.forename: T
authors.initials: T
authors.lastname: Adachi
authors.forename: M
authors.initials: M
authors.lastname: Saiuchi
authors.forename: A
authors.initials: A
authors.lastname: Asada
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002459:Cell Fusion / Q000235:genetics*; D002461:Cell Line, Transformed; D003370:Coturnix; D016391:Genes, src / Q000502:physiology*; D008561:Membrane Fusion / Q000502:physiology; D009132:Muscles / Q000196:embryology*; D011505:Protein-Tyrosine Kinases / Q000502:physiology*; D013696:Temperature
chemical_list: D011505:Protein-Tyrosine Kinases; D002118:Calcium