Nucleolar apparatus function and the ribosomal gene activity of mouse embryonic fibroblasts infected by the SA7(C8) virus

Computer morphometry revealed statistically significant (P less than 0.001) decrease in the number and area of nucleoli and ribosomal gene activities (as demonstrated by AgNOR staining) in primary mouse embryonal fibroblast cultures infected by oncogenic adenovirus SA7(C8). Even more drastic increased in these parameters was found when serum-depleted cultures were infected. There were no effects on nucleolar and AgNOR parameters in mock-infected cultures. It is suggested that an increase in the ribosomal gene activity may reflect synthesis of SA7(C8) early gene products in target cells.