ZFIN ID: ZDB-PUB-190406-11
The maternal to zygotic transition regulates genome-wide heterochromatin establishment in the zebrafish embryo
Laue, K., Rajshekar, S., Courtney, A.J., Lewis, Z.A., Goll, M.G.
Date: 2019
Source: Nature communications   10: 1551 (Journal)
Registered Authors: Goll, Mary, Laue, Kathrin, Rajshekar, Shrivarsha
Keywords: none
Microarrays: GEO:GSE113086
MeSH Terms:
  • Animals
  • Chromatin/genetics
  • Chromatin/metabolism
  • Chromatin/ultrastructure
  • Embryo, Nonmammalian/cytology
  • Embryonic Development/genetics*
  • Gene Expression Regulation, Developmental
  • Heterochromatin/genetics*
  • Heterochromatin/metabolism
  • Heterochromatin/ultrastructure
  • MicroRNAs/metabolism
  • MicroRNAs/physiology
  • Transcription, Genetic
  • Zebrafish/embryology*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
  • Zebrafish Proteins/physiology
PubMed: 30948728 Full text @ Nat. Commun.
The segregation of eukaryotic genomes into euchromatin and heterochromatin represents a fundamental and poorly understood process. Here, we demonstrate that genome-wide establishment of heterochromatin is triggered by the maternal to zygotic transition (MZT) during zebrafish embryogenesis. We find that prior to MZT, zebrafish lack hallmarks of heterochromatin including histone H3 lysine 9 trimethylation (H3K9me3) and condensed chromatin ultrastructure. Global establishment of heterochromatic features occurs following MZT and requires both activation of the zygotic genome and degradation of maternally deposited RNA. Mechanistically, we demonstrate that zygotic transcription of the micro RNA miR-430 promotes degradation of maternal RNA encoding the chromatin remodeling protein Smarca2, and that clearance of Smarca2 is required for global heterochromatin establishment in the early embryo. Our results identify MZT as a key developmental regulator of heterochromatin establishment during vertebrate embryogenesis and uncover functions for Smarca2 in protecting the embryonic genome against heterochromatinization.