Snyers Luc, Zupkovitz Gordin, Almeder Marlene, Fliesser Marianne, Stoisser Anja, Weipoltshammer Klara, Schöfer Christian
a Department for Cell and Developmental Biology; Medical Imaging Cluster; Medical University of Vienna; Vienna, Austria.
Nucleus. 2014 Sep-Oct;5(5):449-61. doi: 10.4161/nucl.36229.
Actively transcribed regions of the genome have been found enriched for the histone H3 variant H3.3. This variant is incorporated into nucleosomes throughout the cell cycle whereas the canonical isoforms are predominately deposited in association with replication. In order to obtain a global picture of the deposition pattern at the single cell level we expressed H3.3 in both normal and malignant human cells and analyzed nuclei using conventional and structured illumination imaging (SIM). We found that the distribution pattern of H3.3 in interphase differs from that of the canonical histone H3 variants and this difference is conveyed to mitotic chromosomes which display a distinct H3.3 banding pattern. Histone H3.3 localization positively correlated with markers for transcriptionally active chromatin and, notably, H3.3 was almost completely absent from the inactive X chromosome. Collectively, our data show that histone variant H3.3 occupies distinct intranuclear chromatin domains and that these genomic loci are associated with gene expression.
人们发现基因组的活跃转录区域富含组蛋白H3变体H3.3。这种变体在整个细胞周期中都被整合到核小体中，而经典亚型主要在复制过程中沉积。为了在单细胞水平上全面了解沉积模式，我们在正常和恶性人类细胞中表达了H3.3，并使用传统成像和结构光照成像（SIM）分析细胞核。我们发现，H3.3在间期的分布模式与经典组蛋白H3变体不同，这种差异传递到有丝分裂染色体上，呈现出独特的H3.3带型。组蛋白H3.3的定位与转录活性染色质标记呈正相关，值得注意的是，失活的X染色体上几乎完全没有H3.3。总体而言，我们的数据表明组蛋白变体H3.3占据不同的核内染色质结构域，并且这些基因组位点与基因表达相关。
