title: [Isolation of rosette-like structures from partially deproteinized chromatin in rat hepatocytes].
abstract: The structure of partial deproteinized rat hepatocyte chromatin has been studied. Depending on the magnesium concentration the chromatin of isolated nuclei is present in the two conditions: diffuse (at 0-1.5 mM MgCl2) and condensed (at 2-5 mM MgCl2). The main components of nuclei with condensed chromatin are chromomers--globular structures about 100 nm in diameter. By treating such nuclei with heparin and dextransulfate one can observe a rosette-like structure with lateral loops having the following parameters: the length of the loops, 15-20 micron; the number of loops, 15-30. The rosette-like structures are sensitive to endogenous nuclease and DNase 1, but not to RNase. Pronase or higher concentration of polyanions give rise to unfolding of the rosette-like structures. The rosette structures cannot be isolated from the nuclei with diffuse chromatin. On the basis of these observations a hypothesis of chromatin structural organization in the interphase nucleus is proposed, and the connection of the rosette-like structures with some structural levels of chromatin organization is discussed.
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D002843:Chromatin / Q000302:isolation & purification* / Q000378:metabolism / Q000648:ultrastructure; D004247:DNA / Q000032:analysis / Q000378:metabolism; D007399:Interphase; D008099:Liver / Q000378:metabolism / Q000648:ultrastructure*; D008274:Magnesium / Q000378:metabolism; D008854:Microscopy, Electron; D011506:Proteins / Q000302:isolation & purification*; D051381:Rats
chemical_list: D002843:Chromatin; D011506:Proteins; D004247:DNA; D008274:Magnesium
vernacular_title: Vydelenie rozetochno-podobnykh struktur iz chastichno deproteinizirovannogo khromatina gepatotsitov krysy.