title: Stabilization of macromolecular chromatin complexes in mitotic chromosomes by light irradiation in the presence of ethidium bromide.
abstract: A method was developed for stabilizing mitotic chromosomes. Light irradiation of permeabilized cells in a low concentration of ethidium bromide made chromatin resistant to high salt concentrations and decondensing buffer. This resistance was abolished by proteinase treatment, but not by DNase or RNase treatment. In photostabilized and extracted chromosomes, chromatin appeared as thick fibers with discrete high electron density regions. These stabilized structures might correspond to the higher-level structures (chromonemata) observed in native chromatin. Moreover, the electron density was higher in the centromeric regions than the chromosome arm material. Thus, the method allows chromatin substructures (chromonemata and centromeric heterochromatin) to be stabilized inside mitotic chromosomes.
authors.affiliation: A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, GSP-2, Moscow 119992, Russia. sheval_e@genebee.msu.su
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Sheval
authors.forename: Igor I
authors.initials: II
authors.lastname: Kireev
authors.forename: Vladimir Yu
authors.initials: VY
authors.lastname: Polyakov
mesh_terms: D000818:Animals; D002021:Buffers; D002478:Cells, Cultured; D002503:Centromere / Q000378:metabolism / Q000648:ultrastructure; D002843:Chromatin / Q000187:drug effects* / Q000528:radiation effects* / Q000648:ultrastructure; D043171:Chromosomal Instability / Q000187:drug effects* / Q000528:radiation effects*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D003851:Deoxyribonucleases / Q000494:pharmacology; D004996:Ethidium / Q000494:pharmacology*; D007202:Indicators and Reagents; D008027:Light; D046911:Macromolecular Substances / Q000528:radiation effects; D046529:Microscopy, Electron, Transmission; D008938:Mitosis / Q000187:drug effects / Q000528:radiation effects; D010447:Peptide Hydrolases / Q000494:pharmacology; D010775:Photic Stimulation; D012313:RNA / Q000378:metabolism; D012260:Ribonucleases / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013194:Staining and Labeling / Q000379:methods*; D013552:Swine
chemical_list: D002021:Buffers; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D007202:Indicators and Reagents; D046911:Macromolecular Substances; D012965:Sodium Chloride; D012313:RNA; D004247:DNA; D003851:Deoxyribonucleases; D012260:Ribonucleases; D010447:Peptide Hydrolases; D004996:Ethidium