Spatial organization of large-scale chromatin domains in the nucleus: a magnified view of single chromosome territories.
Spatial organization of large-scale chromatin domains in the nucleus: a magnified view of single chromosome territories.
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DOI：
10.1083/jcb.139.7.1597
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发表时间：
1997-12-29
期刊：
影响因子：
--
通讯作者：
Lamond AI
中科院分区：
文献类型：
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作者：
Ferreira J;Paolella G;Ramos C;Lamond AI
我们分析了中国仓鼠成纤维细胞，人类淋巴（IM-9），和有袋动物肾上皮（PtK）细胞的大规模染色质结构域的空间组织标记DNA在定义的阶段的S期通过脉冲掺入卤代脱氧核苷。大多数，如果不是全部，染色体贡献多个染色质结构域的外周和内部核质区室。外周室主要包含晚期复制G/Q带，而早期复制R带优先定位于内部核质室。在有丝分裂过程中，标记的染色质结构域在分裂间期分离，沿每个中期染色体的长度形成沿着插入带的模式。染色质结构域从带状（有丝分裂）到区室化（间期）组织的转变发生在末期晚期/早期G1阶段，并且不依赖于基因组的转录激活。有趣的是，几个染色体的微核代表明，早期和晚期复制染色质室的空间分离是独立的染色体数目重演，即使在微核只含有一个染色体。我们的数据有力地支持了这样一种观点，即在完整的细胞核中看到的大规模（条带大小）染色质结构域的区室化是单个染色体区域中发生的类似区室化的放大图像。
We have analyzed the spatial organization of large scale chromatin domains in chinese hamster fibroblast, human lymphoid (IM-9), and marsupial kidney epithelial (PtK) cells by labeling DNA at defined stages of S phase via pulsed incorporation of halogenated deoxynucleosides. Most, if not all, chromosomes contribute multiple chromatin domains to both peripheral and internal nucleoplasmic compartments. The peripheral compartment contains predominantly late replicating G/Q bands, whereas early replicating R bands preferentially localize to the internal nucleoplasmic compartment. During mitosis, the labeled chromatin domains that were separated in interphase form a pattern of intercalated bands along the length of each metaphase chromosome. The transition from a banded (mitotic) to a compartmentalized (interphasic) organization of chromatin domains occurs during the late telophase/early G1 stage and is independent of transcriptional activation of the genome. Interestingly, generation of micronuclei with a few chromosomes showed that the spatial separation of early and late replicating chromatin compartments is recapitulated independently of chromosome number, even in micronuclei containing only a single chromosome. Our data strongly support the notion that the compartmentalization of large-scale (band size) chromatin domains seen in the intact nucleus is a magnified image of a similar compartmentalization occurring in individual chromosome territories.