The effect of herpesvirus infection on ribosomal RNA synthesis and on nucleolar size and number in HeLa cells.

The effects of infection by the herpesvirus pseudorabies virus on the nucleolus and on ribosomal RNA synthesis in HeLa cells were examined. The size of individual nucleoli and the total nucleolar content per cell are reduced to approximately 35 per cent of normal by 6 hours of infection. The proportion of cells containing one nucleolus rises from 10 to 50 per cent in the same time. The synthesis of ribosomal precursor RNA declines to approximately 40 per cent in this period.