title: Detection of lateral asymmetry in the C band of human chromosomes by BrdU-DAPI fluorescence.
abstract: A lateral asymmetry in the C-band region of human chromosomes is revealed by 4',6-diamidino-2-phenylindole (DAPI) fluorescence in amniotic cells grown for one replication cycle in the presence of 5-bromodeoxyuridine (BrdU). Short-arm segments and satellites of acrocentric chromosomes fluoresce as brightly with quinacrine as the distal part of the long arm of the Y chromosome, and also show a lateral asymmetry. This asymmetry appears to be correlated with highly repetitious DNA, including satellite fractions responsible for C-band staining, and may reflect an unequal distribution of thymine residues between the two polynucleotide chains of the DNA in the C-band region. The C-band region of chromosome 9 fluoresces brightly in both sister chromatids and appears to be symmetrical. This may be the result of multiple inversions in the C-band heterochromatic region.
mesh_terms: D001973:Bromodeoxyuridine / Q000378:metabolism; D002478:Cells, Cultured; D002503:Centromere / Q000648:ultrastructure; D002875:Chromosomes / Q000648:ultrastructure*; D004261:DNA Replication; D004276:DNA, Satellite / Q000378:metabolism; D005456:Fluorescent Dyes; D006801:Humans; D013941:Thymine / Q000378:metabolism
chemical_list: D004276:DNA, Satellite; D005456:Fluorescent Dyes; D001973:Bromodeoxyuridine; D013941:Thymine