title: Chicken ribosomal DNA: gene frequency and purification by R-loop hybridization.
abstract: The genes for ribosomal RNA of chicken are present in about 200--240 copies per haploid genome. The ribosomal genes were separated from the bulk of DNA by different methods. In CsCl-actinomycin D gradients the GC-rich ribosomal DNA is shifted to the lower density side of the bulk of DNA. After hybridization with iodinated ribosomal RNA under conditions where R-loops are formed ribosomal DNA has an increased density. The R-loops can be separated from the bulk of DNA in Cs2-SO4 gradients.
mesh_terms: D000818:Animals; D002499:Centrifugation, Density Gradient; D002642:Chick Embryo; D004247:DNA / Q000235:genetics*; D005796:Genes; D009693:Nucleic Acid Hybridization; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D012335:RNA, Ribosomal; D004247:DNA