title: Epigenetic marking of the zebrafish developmental program.
abstract: A characteristic of anamniote development is a relatively long period of embryonic cell divisions in the absence of on-going transcription. In zebrafish, this period lasts for 10 cell cycles, or ∼3-h postfertilization, after which zygotic genome activation (ZGA) takes place during the midblastula transition. How the embryo establishes transcriptional competence and how ZGA is spatially and temporally regulated have not been examined until recently. We review here recent data on the transitions in DNA methylation and posttranslational histone modifications occurring during early zebrafish development, as the embryo acquires transcriptional competence and initiates its own gene expression program. We also address models accounting for the origin of epigenetic states detected in early embryos. From these observations, a concept of epigenetic prepatterning of the embryonic gene expression program prior to the onset of ZGA is emerging. The recent data collectively start shedding light on how ZGA may be programmed and regulated.
authors.affiliation: Stem Cell Epigenetics Laboratory, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Ingrid S
authors.initials: IS
authors.lastname: Andersen
authors.forename: Leif C
authors.initials: LC
authors.lastname: Lindeman
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Reiner
authors.forename: Olga
authors.initials: O
authors.lastname: Østrup
authors.forename: Håvard
authors.initials: H
authors.lastname: Aanes
authors.forename: Peter
authors.initials: P
authors.lastname: Aleström
authors.forename: Philippe
authors.initials: P
authors.lastname: Collas
mesh_terms: D000818:Animals; D019175:DNA Methylation / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics*; D044127:Epigenesis, Genetic; D040582:Inheritance Patterns / Q000235:genetics; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*; D015053:Zygote / Q000378:metabolism