Departament de Bioquímica i Biologia Molecular, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Spain.
FEBS Lett. 2019 Apr;593(8):810-819. doi: 10.1002/1873-3468.13370. Epub 2019 Apr 4.
Early results showed the emanation of chromatin fibers from mitotic chromosomes and nuclei swollen with water. In contrast, under metaphase ionic conditions, it was found that chromatin from mitotic chromosomes is planar and forms multilayered plates. Here, we show that in buffers containing interphase cation concentrations, the chromatin emanated from disrupted nuclei also has a planar morphology. Furthermore, the chromatin fragments produced by micrococcal nuclease digestion of nuclei form the typical beads-on-a-string fibers in the absence of cations, but they self-assemble into plate-like structures in buffers containing magnesium. The plates from interphase nuclei do not form the thick multilayered structures observed in metaphase chromosomes, suggesting that they are more exposed to the medium to facilitate DNA replication and gene expression.
早期的结果表明，染色质纤维从有丝分裂染色体和膨胀的水核中散发出来。相比之下，在中期离子条件下，发现有丝分裂染色体的染色质是平面的，并形成多层板。在这里，我们表明，在含有间期阳离子浓度的缓冲液中，从破裂核中散发出来的染色质也具有平面形态。此外，用微球菌核酸酶消化核产生的染色质片段在没有阳离子的情况下形成典型的珠串纤维，但在含有镁的缓冲液中它们会自组装成片状结构。来自间期核的板不会形成在中期染色体中观察到的厚多层结构，这表明它们更暴露于介质中，以促进 DNA 复制和基因表达。
