Imaging and chromatin capture techniques have provided important insights into our understanding of nuclear organization. A limitation of these techniques is the inability to resolve allele-specific spatiotemporal properties of genomic loci in living cells. Here, we describe an allele-specific CRISPR live-cell DNA imaging technique (SNP-CLING) to provide the first comprehensive insights into allelic positioning across space and time in mouse embryonic stem cells and fibroblasts. With 3D imaging, we studied alleles on different chromosomes in relation to one another and relative to nuclear substructures such as the nucleolus. We find that alleles maintain similar positions relative to each other and the nucleolus; however, loci occupy unique positions. To monitor spatiotemporal dynamics by SNP-CLING, we performed 4D imaging and determined that alleles are either stably positioned or fluctuating during cell state transitions, such as apoptosis. SNP-CLING is a universally applicable technique that enables the dissection of allele-specific spatiotemporal genome organization in live cells.

中文翻译：

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通过等位基因特异的CRISPR活细胞成像（SNP-CLING）进行时空等位基因组织。

成像和染色质捕获技术为我们对核组织的理解提供了重要的见识。这些技术的局限性是无法解析活细胞中基因组基因座的等位基因特异性时空特性。在这里，我们描述了一种等位基因特异的CRISPR活细胞DNA成像技术（SNP-CLING），以提供对小鼠胚胎干细胞和成纤维细胞中时空等位基因定位的第一个综合见解。通过3D成像，我们研究了彼此之间以及相对于核亚结构（如核仁）的不同染色体上的等位基因。我们发现等位基因相对于彼此和核仁保持相似的位置。但是，基因座占据着独特的位置。要通过SNP-CLING监视时空动态，我们进行了4D成像，并确定等位基因在细胞状态转换（例如凋亡）过程中稳定定位或波动。SNP-CLING是一种普遍适用的技术，可在活细胞中解剖等位基因特异性时空基因组组织。