2017年3月13日, 國際學術權威刊物自然出版集團《Nature》雜誌線上發表了英國劍橋大學Ernest D. Laue研究組的一篇研究論文, 研究報導了從單個細胞中確定出完整保存的哺乳動物基因組的首個3D結構, 顯示了細胞核內所有染色體中的DNA是如何複雜地折疊在一起的。
很多人對於呈現“X”形狀的染色體十分熟悉, 但事實上, 染色體僅在細胞分裂時呈現這種形態。 研究人員利用一種圖像組合和對DNA不同部位多達1萬個測量結果, 對實驗鼠胚胎幹細胞內的基因組進行了研究。
利用這種新方法, 研究人員目前已能確定細胞內部各種活躍染色體的結構,
Ernest D. Laue指出:“知道某特定時刻所有基因處於何處及其控制元素, 將説明理解控制和保持其表達的分子機理。 未來我們將能夠研究幹細胞分化時這些變化是如何發生的, 以及在個體幹細胞發育過程中其決定是如何做出的。 目前科學家對這些機理知之甚少, 而對其理解則可能是認識幹細胞在醫藥領域潛能的關鍵。
原文連結:
原文摘要:
The folding of genomic DNA from the beads-on-a-string-like structure of nucleosomes into higher-order assemblies is crucially linked to nuclear processes. Here we calculate 3D structures of entire mammalian genomes using data from a new chromosome conformation capture procedure that allows us to first image and then process single cells. The technique enables genome folding to be examined at a scale of less than 100 kb, and chromosome structures to be validated. The structures of individual topological-associated domains and loops vary substantially from cell to cell. By contrast, A and B compartments, lamina-associated domains and active enhancers and promoters are organized in a consistent way on a genome-wide basis in every cell, suggesting that they could drive chromosome and genome folding. By studying genes regulated by pluripotency factor and nucleosome remodelling deacetylase (NuRD), we illustrate how the determination of single-cell genome structure provides a new approach for investigating biological processes.