In hybrid myotubes, a fusion protein encoded by a single transfected nucleus was not confined to its nucleus of origin but was restricted to nearby nuclei.
In multinucleated myotubes, proteins encoded by a single nucleus can transfer to nearby nuclei, indicating a localized domain of influence rather than strict confinement or global distribution.
Specialized regions of muscle fibers may result from differential gene expression within a single fiber. In order to investigate the range of action of individual nuclei in multinucleated myotubes, C2 myoblasts were transfected to obtain stable cell lines that express a reporter protein that is targeted to the nucleus. Hybrid myotubes were then formed containing one or a few transfected nuclei as well as a large number of nuclei from the parental strain. In order to determine how far the products of a single nucleus extend, transfected nuclei were labeled with 3Hthymidine before fusion and the myotubes were stained to identify the reporter protein. In such myotubes the fusion protein was not confined to its nucleus of origin, but was restricted to nearby nuclei.
Ralston et al. (Fri,) conducted a other in Muscle fiber gene expression. Transfection of C2 myoblasts with a nuclear-targeted reporter protein was evaluated on Distribution of the reporter protein in hybrid myotubes. In hybrid myotubes, a fusion protein encoded by a single transfected nucleus was not confined to its nucleus of origin but was restricted to nearby nuclei.