Rubinstein N A, Pepe F A, Holtzer H
Proc Natl Acad Sci U S A. 1977 Oct;74(10):4524-7. doi: 10.1073/pnas.74.10.4524.
We have studied the myosin types present in developing fast and slow muscles of the chicken embryo. Myosin light chains were characterized by their mobility on sodium dodecyl sulfate/polyacrylamide gels; myosin heavy chains were identified by their reaction with antibodies specific for adult fast or adult slow myosin heavy chains. During development, the pectoralis muscle, a fast muscle in the adult, contains heavy chains and two of the three light chains characteristic of adult fast muscle myosin. However, the anterior latissimus dorsi muscle, a slow muscle in the adult, also contains fast myosin light and heavy chains during early development. Only after the time of innervation does this muscle begin synthesizing predominantly the slow myosin heavy and light chains. We hypothesize that the synthesis of fast myosin in both early fast and slow muscles is the result of the endogenous program for muscle development; initiation of the synthesis of slow myosin, however, is dependent upon exogenous factors.
我们研究了鸡胚发育过程中快肌和慢肌中存在的肌球蛋白类型。肌球蛋白轻链通过其在十二烷基硫酸钠/聚丙烯酰胺凝胶上的迁移率来表征；肌球蛋白重链通过其与成年快肌或成年慢肌肌球蛋白重链特异性抗体的反应来鉴定。在发育过程中，胸肌在成年后是快肌，含有成年快肌肌球蛋白特有的重链和三条轻链中的两条。然而，背阔肌前肌在成年后是慢肌，在发育早期也含有快肌肌球蛋白轻链和重链。只有在神经支配后，这块肌肉才开始主要合成慢肌肌球蛋白重链和轻链。我们推测，早期快肌和慢肌中快肌肌球蛋白的合成是肌肉发育内源性程序的结果；然而，慢肌肌球蛋白合成的启动依赖于外源性因素。
