Paused RNA polymerase II as a developmental checkpoint. Author Michael Levine Publication Year 2011 Type Journal Article Abstract The textbook view of gene activation is that the rate-limiting step is the interaction of RNA polymerase II (Pol II) with the gene's promoter. However, studies in a variety of systems, including human embryonic stem cells and the early Drosophila embryo, have begun to challenge this view. There is increasing evidence that differential gene expression often depends on the regulation of transcription elongation via the release of Pol II from the proximal promoter. I review the implications of this mechanism of gene activation with respect to the orderly unfolding of complex gene networks governing animal development. Keywords Animals, Gene Expression Regulation, Developmental, Humans, Gene Regulatory Networks, Drosophila melanogaster, Promoter Regions, Genetic, Embryonic Stem Cells, RNA Polymerase II Journal Cell Volume 145 Issue 4 Pages 502-11 Date Published 05/2011 Alternate Journal Cell Google ScholarBibTeXEndNote X3 XML