title: Electron-microscopic visualization of transcriptionally active and less active chromatin fractions from the rat ventral prostate and their content of histones.
abstract: The content of histones in transcriptionally active (euchromatin-like (E)) and transcriptionally less active (heterochromatin-like (H)) fractions from the rat ventral prostate was determined. The absolute amount of total histone was less in the E fraction, which contained relatively more stained histone F2b and F3 and less histone F1 than either the H fraction or unfractionated chromatin. The phosphotungstic-acid-stained E fraction was composed predominantly of shorter (50-500 nm) and thinner (5-15 nm) structures. In some preparations, pieces estimated to be 500-1000 + nm in length were present. Spherical structures, from 10 to 20 nm in diameter, some of which were present as 'dimers,' trimers,' or higher-ordered ensembles were seen in the shadow-case E fraction. The stained or shadow-cast H fraction contained longer (200-2000 + nm) and thicker (congruent to 20 nm) fragments with a more complex substructure. When the shadow-cast H fraction was sufficiently dispersed, it had a nodular or 'beaded' appearance.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D002843:Chromatin / Q000378:metabolism* / Q000648:ultrastructure; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006570:Heterochromatin / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D011467:Prostate / Q000378:metabolism*; D051381:Rats; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D006570:Heterochromatin; D006657:Histones