Gamma radiation induces locus specific changes to histone modification enrichment in zebrafish and Atlantic salmon

PLoS One. 2019 Feb 13;14(2):e0212123. doi: 10.1371/journal.pone.0212123. eCollection 2019.


Ionizing radiation is a recognized genotoxic agent, however, little is known about the role of the functional form of DNA in these processes. Post translational modifications on histone proteins control the organization of chromatin and hence control transcriptional responses that ultimately affect the phenotype. The purpose of this study was to investigate effects on chromatin caused by ionizing radiation in fish. Direct exposure of zebrafish (Danio rerio) embryos to gamma radiation (10.9 mGy/h for 3h) induced hyper-enrichment of H3K4me3 at the genes hnf4a, gmnn and vegfab. A similar relative hyper-enrichment was seen at the hnf4a loci of irradiated Atlantic salmon (Salmo salar) embryos (30 mGy/h for 10 days). At the selected genes in ovaries of adult zebrafish irradiated during gametogenesis (8.7 and 53 mGy/h for 27 days), a reduced enrichment of H3K4me3 was observed, which was correlated with reduced levels of histone H3 was observed. F1 embryos of the exposed parents showed hyper-methylation of H3K4me3, H3K9me3 and H3K27me3 on the same three loci, while these differences were almost negligible in F2 embryos. Our results from three selected loci suggest that ionizing radiation can affect chromatin structure and organization, and that these changes can be detected in F1 offspring, but not in subsequent generations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Embryonic Development / genetics
  • Embryonic Development / radiation effects
  • Gametogenesis / radiation effects
  • Gamma Rays / adverse effects*
  • Genetic Loci / genetics
  • Genetic Loci / radiation effects*
  • Histone Code / radiation effects*
  • Histones / chemistry
  • Histones / metabolism
  • Lysine / metabolism
  • Methylation / radiation effects
  • Salmo salar / embryology
  • Salmo salar / genetics*
  • Salmo salar / physiology
  • Zebrafish / embryology
  • Zebrafish / genetics*
  • Zebrafish / physiology


  • Histones
  • Lysine

Grants and funding

This work was supported by the Research Council of Norway (RCN) through its Centre of Excellence (CoE) Centre of Environmental Radiology, funding scheme (Project No. 223268/F50). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.