title: The curious case of bivalent marks.
abstract: Bivalently marked chromatin, containing both histone H3 lysine 4 (H3K4) and H3K27 trimethylation, is a hallmark of developmentally regulated paused promoters in mammalian embryonic stem cells. In this issue of Developmental Cell, Akkers et al. report that Xenopus tropicalis embryos transition through early development without the requirement for bivalently marked promoters.
authors.affiliation: Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA.
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Herz
authors.forename: Shima
authors.initials: S
authors.lastname: Nakanishi
authors.forename: Ali
authors.initials: A
authors.lastname: Shilatifard
mesh_terms: D000818:Animals; D002843:Chromatin / Q000737:chemistry; D053595:Embryonic Stem Cells / Q000166:cytology; D006657:Histones / Q000737:chemistry*; D006801:Humans; D008239:Lysine / Q000737:chemistry*; D008954:Models, Biological; D008957:Models, Genetic; D009707:Nucleosomes / Q000378:metabolism; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D014158:Transcription, Genetic; D014981:Xenopus / Q000196:embryology*
chemical_list: D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D008239:Lysine