Ag-NOR staining and a counterstain enhanced fluorescence technique (chromomycin A
3/distamycin A/DAPI-staining = CDD-method) and G-banding, respectively, have been applied to the zebu (
Bos indicus L.) chromosomes. The nucleolus organizer regions (NORs) were found in the telomeric regions of chromosomes nos. 2, 3, 4, 11, and 28. CDD staining led to a well-defined R-banding pattern along the chromosome arms and to the visualization of centric heterochromatic bands of variable sizes.
Key words Zebu cattle - Nucleolus organizers - Heterochromatin polymorphisms
Communicated by F. Mechelke