Differences between Prokaryotic and Eukaryotic Gene Expression and Regulation RNA polymerase in prokaryotes can access almost any promoter in a dNa strand without the presence of activators or repressors. Thus, the"ground state"of DNA expression in prokaryotes is said to be nonrestrictive,or on "In eukaryotes, however, the ground state of expression is restrictive in that, although strong promoters might be present, they are inactive in the absence of some sort of recruitment to the promoter by transcription factors From Phillips T: Regulation of transcription and gene expression in eukaryotes Nature Education 2008, 1(1)Differences Between Prokaryotic and Eukaryotic Gene Expression and Regulation • RNA polymerase in prokaryotes can access almost any promoter in a DNA strand without the presence of activators or repressors. Thus, the "ground state" of DNA expression in prokaryotes is said to be nonrestrictive, or "on." In eukaryotes, however, the ground state of expression is restrictive in that, although strong promoters might be present, they are inactive in the absence of some sort of recruitment to the promoter by transcription factors. From Phillips T: Regulation of transcription and gene expression in eukaryotes. Nature Education 2008, 1(1)