Meinnel T, Libri D, Gros D, Fiszman M Y, Lemonnier M
Département de Biologie moléculaire, Institut Pasteur, Paris.
Reprod Nutr Dev (1980). 1988;28(3B):715-20.
Accumulation of mRNAs coding for alpha and beta skeletal tropomyosins was investigated using specific probes and normalized to muscle creatine kinase (M-CK) mRNA by slot-blot assays. In developing pectoralis muscle, the ratio of alpha TM messenger/M-CK remained constant until hatching, at which time the messenger disappeared within a week. However, in the leg, this ratio remained constant until 8 days after hatching, whereafter it decreased progressively to reach 30% in the adult. The alpha TM/M-CK ratios were almost the same in the embryonic leg and pectoralis muscle. After hatching, there was a large increase in pectoralis muscle (x 3 at day +4, x 0 at day +21) whereas, the increase was less pronounced and more progressive in the leg (x 3 at day 21). Run-on assays showed that nuclei isolated from 15-day in ovo leg and pectoralis muscles had similar patterns of muscle specific gene transcription whereas post-hatched pectoralis muscle nuclei were shown to have a higher rate of alpha to beta tropomyosin gene transcription. These data are in accordance with the results obtained for protein analysis of leg and pectoralis muscles and support the notion that changes in the protein pattern of developing muscle can be relevant to coordinate regulation of gene transcription.
使用特异性探针研究了编码α和β骨骼肌原肌球蛋白的mRNA的积累情况，并通过狭缝印迹分析将其与肌肉肌酸激酶（M-CK）mRNA进行标准化。在发育中的胸肌中，αTM信使RNA/M-CK的比值在孵化前保持恒定，此时信使RNA在一周内消失。然而，在腿部，该比值在孵化后8天前保持恒定，此后逐渐下降，在成年时降至30%。胚胎期腿部和胸肌中的αTM/M-CK比值几乎相同。孵化后，胸肌中有大幅增加（第4天增加3倍，第21天增加0倍），而腿部的增加则不太明显且更为渐进（第21天增加3倍）。核转录分析表明，从孵化15天的胚胎腿部和胸肌中分离出的细胞核具有相似的肌肉特异性基因转录模式，而孵化后的胸肌细胞核显示出α原肌球蛋白基因与β原肌球蛋白基因转录的更高比率。这些数据与腿部和胸肌蛋白质分析的结果一致，并支持这样一种观点，即发育中肌肉蛋白质模式的变化可能与基因转录的协调调节相关。
