Patterns of silver staining on NORs of prematurely condensed muntjac chromosomes following RNA inhibition

Abstract

Prematurely condensed chromosomes of muntjac G0 lymphocytes as well as contact-inhibited and Actinomycin D (actD)-treated fibroblasts have been stained with silver nitrate to estimate the correlation between RNA suppression and the NOR staining. The results demonstrate that actD treatment for up to 36 h does not significantly affect the staining. Only partial suppression occurs in contact-inhibited cells, whereas complete abolition is obtained in long quiescent lymphocytes. We conclude that the reduction of the staining occurs only gradually from the NORs over a number of days or even weeks. We assume that the silver staining proteins may be associated with rDNA having a regulatory or structural role to play in rDNA activity.