title: Drosophila poised enhancers are generated during tissue patterning with the help of repression.
abstract: Histone modifications are frequently used as markers for enhancer states, but how to interpret enhancer states in the context of embryonic development is not clear. The poised enhancer signature, involving H3K4me1 and low levels of H3K27ac, has been reported to mark inactive enhancers that are poised for future activation. However, future activation is not always observed, and alternative reasons for the widespread occurrence of this enhancer signature have not been investigated. By analyzing enhancers during dorsal-ventral (DV) axis formation in the Drosophila embryo, we find that the poised enhancer signature is specifically generated during patterning in the tissue where the enhancers are not induced, including at enhancers that are known to be repressed by a transcriptional repressor. These results suggest that, rather than serving exclusively as an intermediate step before future activation, the poised enhancer state may be a mark for spatial regulation during tissue patterning. We discuss the possibility that the poised enhancer state is more generally the result of repression by transcriptional repressors.
authors.affiliation: Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.
authors.forename: Nina
authors.initials: N
authors.lastname: Koenecke
authors.affiliation: Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.
authors.forename: Jeff
authors.initials: J
authors.lastname: Johnston
authors.affiliation: Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.
authors.forename: Qiye
authors.initials: Q
authors.lastname: He
authors.affiliation: Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Meier
authors.affiliation: Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.|University of Kansas Medical Center, Department of Pathology, Kansas City, Kansas 66160, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Zeitlinger
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D004330:Drosophila / Q000235:genetics / Q000254:growth & development; D047108:Embryonic Development / Q000235:genetics*; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D063185:Epigenetic Repression / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D042421:Histone Code / Q000235:genetics; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D014157:Transcription Factors; D011495:Histone-Lysine N-Methyltransferase