ABSTRACT
The inhibition of host genetic expression is a common but not invariable consequence of virus infection. This chapter summarizes the characteristics of some eukaryotic genes that have been employed to study viral effects on host cell messenger riboNucleic acid (mRNA) production. Since the inhibition of host cell mRNA production by animal viruses is exercised by different strategies and at different levels, to understand the molecular mechanism involved in virus-directed suppression it is necessary to analyze the nuclear and cytoplasmic mRNA from a single gene. The analysis of the signals for transcription was facilitated by progress in the manipulation of recombinant deoxyribonucleic acid, and by the development of in vitro systems that allow the assay of the effects of template-directed alterations. Point mutations in the promoter region have also demonstrated that specific sequences play an important role in determining the level of transcription in a variety of eukaryotic promoters.
