MyoD, myogenin independent differentiation of primordial myoblasts in mouse somites.
MyoD, myogenin independent differentiation of primordial myoblasts in mouse somites.
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DOI：
10.1083/jcb.116.5.1243
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发表时间：
1992-03
影响因子：
7.8
通讯作者：
Buckingham, M
中科院分区：
文献类型：
--
作者：
Cusella-De Angelis, M G;Lyons, G;Sonnino, C;De Angelis, L;Vivarelli, E;Farmer, K;Wright, W E;Molinaro, M;Bouche, M;Buckingham, M
通过双免疫细胞化学研究了两种成肌调节蛋白MyoD和肌细胞生成素的积累，并与培养中和体内早期成肌细胞中不同类别的成肌细胞中的肌球蛋白重链表达相关。在胎儿成肌细胞的体外分化过程中，首先检测到MyoD阳性细胞，然后是MyoD和肌细胞生成素阳性细胞的出现，最后是表达肌球蛋白重链（MHC）的分化肌细胞和肌管的出现。在胚胎和卫星细胞培养物中观察到类似的表达模式。相比之下，大多数从新形成的体节中分离的肌源性细胞在没有可检测水平的肌细胞生成素或MyoD的情况下表达MHC。在体内，肌细胞生成素和MyoD蛋白的出现仅在注射后10.5天（d.p.c.）检测到，当终末分化的肌细胞已经可以在肌节中被识别时。10.5-D-老胚胎的尾部肌节的parasobacterium部分显示，收缩蛋白的表达之前的肌细胞生成素或MyoD的表达，当共表达，MHC和肌细胞生成素没有共定位在所有的细胞的肌节。然而，在肢芽中，在第11天，在近端区域可以观察到许多肌细胞生成素（或MyoD）阳性/MHC阴性细胞。在进一步的胚胎发育过程中，这些蛋白质的表达在所有检查的肌肉anlagens中保持恒定，在胎儿晚期降低到低水平。Western和北方分析证实，只有在10.5 d.p.c.后才能检测到肌细胞生成素蛋白。虽然相应的信息在9.5d.p.c.清楚地存在，这强烈表明在胚胎发育的这一阶段肌细胞生成素的转录后调节。这些数据表明，在小鼠肌节中出现的第一个肌源性细胞，并且可以从其培养，在其细胞质中积累肌肉结构蛋白，而不表达可检测水平的肌细胞生成素蛋白（尽管信息明显积累）。在这些细胞中检测不到MyoD信息或蛋白，这可能代表了一个独特的肌源性群体，其在发育中的作用仍有待确定。
The accumulation of two myogenic regulatory proteins, MyoD and myogenin, was investigated by double-immunocytochemistry and correlated with myosin heavy chain expression in different classes of myoblasts in culture and during early myogenesis in vivo. During in vitro differentiation of fetal myoblasts, MyoD-positive cells were detected first, followed by the appearance of cells positive for both MyoD and myogenin and finally by the appearance of differentiated myocytes and myotubes expressing myosin heavy chain (MHC). A similar pattern of expression was observed in cultures of embryonic and satellite cells. In contrast, most myogenic cells isolated from newly formed somites, expressed MHC in the absence of detectable levels of myogenin or MyoD. In vivo, the appearance of both myogenin and MyoD proteins was only detected at 10.5 d postcoitum (d.p.c.), when terminally differentiated muscle cells could already be identified in the myotome. Parasagittal sections of the caudal myotomes of 10.5-d-old embryos showed that expression of contractile proteins preceded the expression of myogenin or MyoD and, when coexpressed, MHC and myogenin did not co-localize within all the cells of the myotome. In the limb bud, however, many myogenin (or MyoD) positive/MHC negative cells could be observed in the proximal region at day 11. During further embryonic development the expression of these proteins remained constant in all the muscle anlagens examined, decreasing to a low level during the late fetal period. Western and Northern analysis confirmed that the myogenin protein could only be detected after 10.5 d.p.c. while the corresponding message was clearly present at 9.5 d.p.c., strongly suggesting a posttranscriptional regulation of myogenin during this stage of embryonic development. These data show that the first myogenic cells which appear in the mouse myotome, and can be cultured from it, accumulate muscle structural proteins in their cytoplasm without expressing detectable levels of myogenin protein (although the message is clearly accumulated). Neither MyoD message or protein are detectable in these cells, which may represent a distinct myogenic population whose role in development remains to be established.