Formation and stability of cytoplasmic mRNAs during myoblast differentiation: pulse-chase and density labeling analyses.
Formation and stability of cytoplasmic mRNAs during myoblast differentiation: pulse-chase and density labeling analyses.
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成肌细胞分化过程中细胞质 mRNA 的形成和稳定性：脉冲追踪和密度标记分析。
DOI：
10.1016/0012-1606(80)90505-9
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发表时间：
1980
影响因子：
2.7
通讯作者：
Charles P. Emerson
中科院分区：
文献类型：
--
作者：
Lewis Bowman;Charles P. Emerson
细胞质mRNA的稳定性和形成率已在胚胎鹌鹑乳房成肌细胞分化形成肌纤维的培养物中定量测定。尿苷脉冲追踪研究表明，分裂的成肌细胞和分化的纤维形成短寿命和长寿命的mRNA。成肌细胞和纤维中的短寿命mRNA具有2-4小时的相似半衰期，然而，长寿命mRNA在成肌细胞中具有60-100小时的半衰期，而在纤维中仅具有20小时的半衰期。当成肌细胞融合时，长寿命细胞质mRNA的形成增加至少两倍，并且这种增加的形成连同融合时成肌细胞分裂的停止足以解释在纤维中观察到的长寿命mRNA的四到五倍积累。用15 N，13 C-核苷酸标记培养物，用轻核苷追踪，然后在小麦胚芽提取物中翻译这些标记的mRNA，鉴定这些长寿命的mRNA。这些实验表明，收缩蛋白mRNA以及60-70种其他肌肉mRNA是由肌纤维主动合成的，并且检测到的所有特异性mRNA的半衰期都集中在20小时左右。
Stabilities and rates of formation of cytoplasmic mRNAs have been measured quantitatively in cultures of embryonic quail breast myoblasts undergoing differentiation to form muscle fibers. Uridine pulse-chase studies show that dividing myoblasts and differentiated fibers form both short- and long-lived mRNAs. Short-lived mRNAs in myoblasts and fibers have similar half-lives of 2–4 hr, however, long-lived mRNAs have a half-life of 60–100 hr in myoblasts and only 20 hr in fibers. When myoblasts fuse, the formation of long-lived cytoplasmic mRNAs increases at least twofold, and this increased formation together with the cessation of myoblast cell division at fusion is sufficient to account for the four- to fivefold accumulation of long-lived mRNA observed in fibers. These long-lived mRNAs were identified by density labeling cultures with15N,13C-nucleotides, chasing with light nucleosides, and then translating the density labeled mRNAs in wheat germ extracts. These experiments show that the contractile protein mRNAs, as well as 60–70 other muscle mRNAs are actively synthesized by muscle fibers and that all of the specific mRNAs detected have half-lives clustering around 20 hr.