Enhanced histone acetylation and transcription: A dynamic perspective

Stably enhanced histone acetylation has long been regarded as a condition of transcriptionally active genes. Recent papers suggest a more dynamic model, with rapid turnover of acetylation observed at nontranscribing poised genes and shown to be an important determinant of transcriptional efficiency upon gene induction. Are these special cases, restricted to specific genes and specific types of histone modifications, or could the entire panoply of histone modifications associated with transcription now be revisited with a much more dynamic perspective?