Human nucleolus organizers on nonhomologous chromosomes can share the same ribosomal gene variants.
The distributions of three human ribosomal gene polymorphisms among individual chromosomes containing nucleolus organizers were analyzed by using mouse--human hybrid cells. Different nucleolus organizers can contain the same variant, suggesting the occurrence of genetic exchanges among ribosomal gene clusters on nonhomologous chromosomes. Such exchanges appear to occur less frequently in mice. This difference is discussed in terms of the nucleolar organization and chromosomal location of ribosomal gene clusters in humans and mice.
D000818:Animals; D002466:Cell Nucleolus / Q000502:physiology*; D004262:DNA Restriction Enzymes; D005787:Gene Frequency; D005796:Genes; D006801:Humans; D006822:Hybrid Cells; D051379:Mice; D009697:Nucleolus Organizer Region / Q000502:physiology*; D011110:Polymorphism, Genetic; D012335:RNA, Ribosomal / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid
D012335:RNA, Ribosomal; D004262:DNA Restriction Enzymes