Variable positions of NORs in Mus musculus.
Silver-NOR staining has been applied to mouse (Mus musculus) chromosomes of different feral populations from Italy, Yougoslavia, and Germany and to chromosomes of M. spretus, a closely related species, from Portugal. In addition to the known pattern of proximal sites on smaller autosomes, terminal sites with silver-NORs on chromosomes 4 and 13 were detected. In M. spretus only terminal NORs were present on chromosomes 4, 13, and 19. Thus, the location of silver-NORs within the genus Mus and M. musculus subspecies shows wide variation.
D000818:Animals; D002871:Chromosome Banding; D002874:Chromosome Mapping; D002875:Chromosomes / Q000648:ultrastructure; D005260:Female; D007621:Karyotyping; D008297:Male; D051379:Mice / Q000235:genetics*; D009697:Nucleolus Organizer Region / Q000648:ultrastructure*; D013045:Species Specificity; D013194:Staining and Labeling