This review is devoted to the mechanisms of transcriptional pause and poised state of RNA polymerase II. Features of poised promoters and chromatin are considered in brief. Role of regulated transcriptional pause as discrete and important stage in regulation of master genes that determine stem-cell differentiation, cell lineage and development in Metazoa is discussed. This work was supported by the Russian Science Foundation (project No. 14-50-00131).
Keywords: RNA polymerase II; chromatin; master regulation; promoter; transcription.