Dolidze M G, Tikhonenko A S, Beliaeva N N, Trakht I N, Severin E S
Tsitologiia. 1981 Aug;23(8):901-6.
The chromatin structure of Physarum polycephalum was studied with electron microscope at different phases of its mitotic cycle. At the S-phase and during mitosis, the chromatin has a nucleosomal structure. At the early G2-phase the chromatin structure changes, long regions of non-beaded structure being found in the chromatin fibers. At the late G2-phase, the major part of chromatin loses its globular organization, with chromatin fibres without a pronounced subunit structure prevailing in the preparations. Biochemical data show that the amount of chromatin resistant to staphylococcal nuclease varies during the mitotic cycle. The amount of nuclease-resistant chromatin is equal to 80% at the S-phase, to decrease up to 50-60% by the early G2-phase. Successive changes of chromatin structure at different levels of its transcriptional activity are found. Lability of nucleosomes is shown to increase with the increase in the transcriptional activity of chromatin, thus leading presumably to the chromatin structural alterations during the mitotic cycle.
利用电子显微镜对多头绒泡菌有丝分裂周期不同阶段的染色质结构进行了研究。在S期和有丝分裂期间，染色质具有核小体结构。在G2期早期，染色质结构发生变化，在染色质纤维中发现了长的无珠状结构区域。在G2期晚期，大部分染色质失去其球状组织，制备物中主要是没有明显亚基结构的染色质纤维。生化数据表明，在有丝分裂周期中，对葡萄球菌核酸酶有抗性的染色质数量会发生变化。在S期，抗核酸酶染色质的数量等于80%，到G2期早期会减少到50-60%。发现染色质在其转录活性的不同水平上有连续的结构变化。结果表明，核小体的不稳定性随着染色质转录活性的增加而增加，这可能导致有丝分裂周期中染色质结构的改变。
