[Structural study of the chromatin of the myxomycete Physarum polycephalum in the mitotic cycle].
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.
D002843:Chromatin / Q000648:ultrastructure*; D007399:Interphase; D008854:Microscopy, Electron; D008938:Mitosis; D010804:Physarum / Q000648:ultrastructure*
D002843:Chromatin
Izuchenie struktury khromatina miksomitseta Physarum polycephalum v mitoticheskom tsikle.