Newlands S, Levitt L K, Robinson C S, Karpf A B, Hodgson V R, Wade R P, Hardeman E C
Muscle Development Unit, Children's Medical Research Institute, Wentworthville, New South Wales 2145, Australia.
Genes Dev. 1998 Sep 1;12(17):2748-58. doi: 10.1101/gad.12.17.2748.
We report a novel mechanism of gene regulation in skeletal muscle fibers. Within an individual myofiber nucleus, not all muscle loci are transcriptionally active at a given time and loci are regulated independently. This phenomenon is particularly remarkable because the nuclei within a myofiber share a common cytoplasm. Both endogenous muscle-specific and housekeeping genes and transgenes are regulated in this manner. Therefore, despite the uniform protein composition of the contractile apparatus along the length of the fiber, the loci that encode this structure are not transcribed continuously. The total number of active loci for a particular gene is dynamic, changing during fetal development, regeneration, and in the adult, and potentially reflects the growth status of the fiber. The data reveal that transcription in particular stages of muscle fiber maturation occurs in pulses and is defined by a stochastic mechanism.
我们报告了骨骼肌纤维中一种新的基因调控机制。在单个肌纤维核内，并非所有肌肉基因座在给定时间都处于转录活跃状态，且基因座是独立调控的。这种现象尤为显著，因为肌纤维内的核共享一个共同的细胞质。内源性肌肉特异性基因、管家基因和转基因均以这种方式受到调控。因此，尽管沿纤维长度方向收缩装置的蛋白质组成是均匀的，但编码该结构的基因座并非持续转录。特定基因的活跃基因座总数是动态的，在胎儿发育、再生和成年期会发生变化，并且可能反映了纤维的生长状态。数据显示，肌纤维成熟特定阶段的转录以脉冲形式发生，且由一种随机机制决定。
