Mouly V, Toutant M, Fiszman M Y
Cell Differ. 1987 Jan;20(1):17-25. doi: 10.1016/0045-6039(87)90461-1.
Evidence is presented which shows that myoblasts, isolated at different stages during chick and quail limb bud development, will form, in culture, myotubes which can be distinguished with a combination of morphological as well as biochemical criteria. Hind limb bud myoblasts isolated from 5-day-old embryos form very short myotubes which synthesize a myosin, the light chains of which are predominantly LC1F and LC2S. Myoblasts isolated from the limb buds of 7-8-day-old embryos form large myotubes which synthesize a myosin the light chains of which are predominantly LC1F, LC2S and LC2F. Myoblasts isolated from the thigh muscle of embryos older than 10 days form large myotubes which synthesize a myosin the light chains of which are predominantly LC1F and LC2F. These results have been confirmed by hybridization of the cellular mRNA with a molecular probe specific for LC2F. These results lead us to suggest the existence of at least two classes of myoblasts which appear at different times during limb bud development. The first class, or 'early' myoblasts, is present in the limb buds of 5-day-old embryos, whereas the second class, or 'late' myoblasts, is present in the muscles of embryos older than 8 days. This result, however, is also compatible with the hypothesis that all muscle cells are the same at all times during development, and that the different phenotypes simply reflect differences in the environmental conditions.
有证据表明，在鸡和鹌鹑肢体芽发育的不同阶段分离出的成肌细胞，在培养中会形成肌管，这些肌管可以通过形态学和生化标准相结合的方式进行区分。从5日龄胚胎分离出的后肢芽成肌细胞形成非常短的肌管，这些肌管合成一种肌球蛋白，其轻链主要是LC1F和LC2S。从7 - 8日龄胚胎的肢体芽分离出的成肌细胞形成大的肌管，这些肌管合成一种肌球蛋白，其轻链主要是LC1F、LC2S和LC2F。从10日龄以上胚胎的大腿肌肉分离出的成肌细胞形成大的肌管，这些肌管合成一种肌球蛋白，其轻链主要是LC1F和LC2F。细胞mRNA与针对LC2F的分子探针杂交证实了这些结果。这些结果使我们提出，在肢体芽发育过程中至少存在两类在不同时间出现的成肌细胞。第一类，即“早期”成肌细胞，存在于5日龄胚胎的肢体芽中，而第二类，即“晚期”成肌细胞，存在于8日龄以上胚胎的肌肉中。然而，这一结果也与以下假设相符：在发育过程中的所有时间里，所有肌肉细胞都是相同的，不同的表型仅仅反映了环境条件的差异。
