title: The location of ribosomal cistrons (rDNA) in chromosomes of the rat.
abstract: In situ hybridization of 3H-labelled ribosomal RNA to the chromosomes of rat bone marrow cells revealed that clusters of ribosomal cistrons (rDNA) are located in the secondary constrictions of chromosomes No. 3 and 12 and near the centromere of chromosome No. 11, both associated with the late DNA-replicating regions. They were not found in Nos. 1, 2, 13, 19, 20, and the Y chromosome.
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D004247:DNA / Q000032:analysis*; D005260:Female; D008297:Male; D009693:Nucleic Acid Hybridization; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D051381:Rats
chemical_list: D012335:RNA, Ribosomal; D004247:DNA