Formation of compact globular particles in interphase nuclei from rat liver under the effect of polyanions.
Treatment of the isolated nuclei with polyanions (PA) (heparin and dextran-sulfate) at the PA/DNA ratio of about 1 in the 0.15-0.5 M ammonium acetate solution leads to rearrangement of the chromatin structure and formation of compact globular particles (GP) 40-70 nm in diameter, bound by fibrils of variable thickness (2-10 nm). GP formation is accompanied by a loss of nucleosomal periodicity in DNA organization. However, no considerable loss of the DNA contents has been found. At the PA/DNA ratio of more than 2, destruction of the DNP-network and aggregation of GP in larger globular structures are observed. The same effect is observed under the nuclease treatment. Under this condition nuclei lose a considerable part of DNA, but retain histones supposedly as histone-PA aggregates. Therefore the joint effect of PA and salt on nuclei at certain conditions may lead to formation of artefact structures.
A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
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AN
Prusov
D
D
Fais
Polyakov VYu
D000818:Animals; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure*; D002843:Chromatin / Q000187:drug effects / Q000648:ultrastructure*; D004247:DNA / Q000032:analysis; D016264:Dextran Sulfate / Q000494:pharmacology*; D006493:Heparin / Q000494:pharmacology*; D007399:Interphase; D008099:Liver / Q000166:cytology* / Q000187:drug effects / Q000648:ultrastructure; D008854:Microscopy, Electron; D051381:Rats
D002843:Chromatin; D006493:Heparin; D004247:DNA; D016264:Dextran Sulfate