title: The role of proteins in the production of different types of chromosome bands.
abstract: Experiments have been carried out to try and answer two questions on the role of proteins in chromosome banding: firstly, what degree of protein extraction is required before banding can be produced; and secondly, to what extent are redistribution and reorganization of chromosomal components required for the production of banding. Partial extraction of all histones, and of a group of non-histones with molecular weights mainly between 50,000 and 70,000 appears to be necessary before G-, C- or R-banding can be produced. More extensive 'dehistonization' to produce chromosome scaffolds inhibits the production of all types of bands. Protein-protein and protein-DNA cross-linking inhibits all types of banding tested, the degree of inhibition being roughly related to the degree of cross-linking, but not apparently to the type of cross-linking. The results of both sets of experiments indicate that chromosome banding of all types is dependent on the prior loss from chromosomes of a specific set of proteins, and on some alteration of the arrangement of remaining chromosomal components during the banding procedure.
mesh_terms: D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D002871:Chromosome Banding; D002875:Chromosomes / Q000648:ultrastructure*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004247:DNA; D006657:Histones / Q000502:physiology*; D006801:Humans; D008214:Lymphocytes; D013194:Staining and Labeling; D014466:Ultraviolet Rays
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D003432:Cross-Linking Reagents; D006657:Histones; D004247:DNA