Bennett G S, Fellini S A, Toyama Y, Holtzer H
J Cell Biol. 1979 Aug;82(2):577-84. doi: 10.1083/jcb.82.2.577.
The distribution of intermediate filament (IF) subunits during maturation of skeletal myotubes in vitro was examined by immunofluorescence, using antibodies against two different types of chick IF subunits: (a) 58-kdalton subunits of fibroblasts (anti-58K), and (b) 55-kdalton subunits of smooth muscle (anti-55K). Anti-58K bound to a filament network in replicating presumptive myoblasts and fibroblasts, as well as in immature myotubes. The distribution in immature myotubes was in longitudinal filaments throughout the cytoplasm. With maturation, staining of myotubes by anti-58K diminished and eventually disappeared. Anti-55K selectively stained myotubes, and the fluorescence localization underwent a drastic change in distribution with maturation--from dense, longitudinal filaments in immature myotubes to a cross-striated distribution in mature myotubes that was associated with the I--Z region of myofibrils. However, the emergence of a cross-striated anti-55K pattern did not coincide temperally with the emergence of striated myofibrils, but occurred over a period of days thereafter.
利用针对两种不同类型鸡中间丝（IF）亚基的抗体，通过免疫荧光法检测了体外培养的骨骼肌肌管成熟过程中IF亚基的分布情况：（a）成纤维细胞的58-kDa亚基（抗58K），以及（b）平滑肌的55-kDa亚基（抗55K）。抗58K与正在增殖的假定成肌细胞、成纤维细胞以及未成熟肌管中的丝状网络结合。在未成熟肌管中，其分布于整个细胞质的纵向细丝中。随着成熟，抗58K对肌管的染色减弱并最终消失。抗55K选择性地对肌管进行染色，并且随着成熟，荧光定位的分布发生了剧烈变化——从未成熟肌管中的密集纵向细丝变为成熟肌管中与肌原纤维I-Z区相关的横纹分布。然而，抗55K横纹模式的出现与横纹肌原纤维的出现并不同时发生，而是在此后数天内出现。
