Nucleolus organizer activity and the origin of Robertsonian translocations.
Chromosomes with active nucleolus organizer regions (NOR's) were identified by combined Q-banding (in some cases), and silver staining in mouse cell lines. NOR-bearing chromosomes were overrepresented among the chromosomes involved in Robertsonian translocations in LM(TK-), A9, and RAG cell lines. Usually only one NOR-bearing chromosome was seen in any biarmed chromosome; relatively few contained two NOR-bearing chromosomes. Thus the nucleolus plays an important role, but nucleolar fusion is relatively unimportant, in the origin of Robertsonian translocations in the mouse.
D000818:Animals; D002460:Cell Line; D002466:Cell Nucleolus / Q000648:ultrastructure*; D002875:Chromosomes / Q000648:ultrastructure*; D051379:Mice; D013194:Staining and Labeling; D014178:Translocation, Genetic