Asymmetric division and cosegregation of template DNA strands in adult muscle satellite cells
Asymmetric division and cosegregation of template DNA strands in adult muscle satellite cells
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DOI：
10.1038/ncb1425
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发表时间：
2006-07-01
影响因子：
21.3
通讯作者：
Tajbakhsh, Shahragim
中科院分区：
文献类型：
--
作者：
Shinin, Vasily;Gayraud-Morel, Barbara;Tajbakhsh, Shahragim
卫星细胞保证出生后骨骼肌的生长和修复。尽管进行了广泛的研究，但其干细胞特性在很大程度上仍不明确。使用脉冲追踪标记BrdU标记假定的干细胞龛，我们确定了一个亚群的标记保留卫星细胞在生长过程中和损伤后。引人注目的是，这些细胞中的一些显示选择性模板DNA链分离在有丝分裂过程中的肌纤维在体内，以及在文化独立于他们的小生境，表明基因组DNA链是不等价的。此外，我们表明，不对称的细胞命运决定因素Numb分离选择性的一个子细胞在有丝分裂和分化前，这表明Numb与自我更新。最后，我们表明，模板DNA与Numb共分离的标记保留细胞，表达自我更新标记Pax7。“不朽”模板DNA链的共分离及其与不对称装置的联系对干细胞生物学和癌症具有重要意义。
Satellite cells assure postnatal skeletal muscle growth and repair. Despite extensive studies, their stem cell character remains largely undefined. Using pulse-chase labelling with BrdU to mark the putative stem cell niche, we identify a subpopulation of label-retaining satellite cells during growth and after injury. Strikingly, some of these cells display selective template-DNA strand segregation during mitosis in the muscle fibre in vivo, as well as in culture independent of their niche, indicating that genomic DNA strands are nonequivalent. Furthermore, we demonstrate that the asymmetric cell-fate determinant Numb segregates selectively to one daughter cell during mitosis and before differentiation, suggesting that Numb is associated with self-renewal. Finally, we show that template DNA cosegregates with Numb in label-retaining cells that express the self-renewal marker Pax7. The cosegregation of 'immortal' template DNA strands and their link with the asymmetry apparatus has important implications for stem cell biology and cancer.