Specific Changes in the Distribution Pattern of Silver-stained Nucleolar Organizer Regions in Chemically Transformed Rat Glial Cells

Ag-NORs in two GA cell lines, derived from chemically transformed glioblasts of WKA and BDIX rats were investigated. The distribution patterns of Ag-NORs among chromosomes nos. 3, 11 and 12 in normal glioblasts varied between two rat strains. The Ag-NOR pattern in GA cell lines, on the other hand, was different from the respective normal one but it was similar between two cells. The identical NOR abnormalities have also been observed in the virus-transformed glial cells. The results combined from both studies showed that specific changes in the Ag-NOR pattern are associated with in vitro transformation of rat glioblasts regardless of the type of the carcinogenic agent, rat strain as well as the karyotype.