PUBLICATION

Tritiated water exposure disrupts myofibril structure and induces mis-regulation of eye opacity and DNA repair genes in zebrafish early life stages

Authors
Arcanjo, C., Armant, O., Floriani, M., Cavalie, I., Camilleri, V., Simon, O., Orjollet, D., Adam-Guillermin, C., Gagnaire, B.
ID
ZDB-PUB-180512-11
Date
2018
Source
Aquatic toxicology (Amsterdam, Netherlands)   200: 114-126 (Journal)
Registered Authors
Armant, Olivier
Keywords
Eye opacity, Genotoxicity, Muscle contraction, RNA sequencing, Tritiated water, Zebrafish
MeSH Terms
  • Animals
  • DNA Damage/genetics
  • DNA Repair/genetics*
  • Embryo, Nonmammalian/drug effects
  • Eye/drug effects*
  • Gene Expression Profiling
  • Gene Expression Regulation, Developmental/drug effects*
  • Hydrogen Peroxide/metabolism
  • Larva/drug effects
  • Larva/genetics
  • Life Cycle Stages/drug effects*
  • Life Cycle Stages/genetics
  • Muscles/drug effects
  • Muscles/ultrastructure
  • Myofibrils/chemistry*
  • Oxidative Stress/drug effects
  • Principal Component Analysis
  • Signal Transduction/drug effects
  • Transcriptome/genetics
  • Tritium/pharmacology*
  • Water/pharmacology*
  • Water Pollutants, Chemical/toxicity
  • Zebrafish/genetics*
  • Zebrafish/growth & development
  • Zebrafish/physiology
PubMed
29751158 Full text @ Aquat. Toxicol.
Abstract
Tritium (3H) is a radioactive isotope of hydrogen. In the environment, the most common form of tritium is tritiated water (HTO). The present study aimed to identify early biomarkers of HTO contamination through the use of an aquatic model, the zebrafish (Danio rerio). We used the zebrafish embryo-larvae model to investigate the modes of action of HTO exposure at dose rates of 0.4 and 4 mGy/h, dose rates expected to induce deleterious effects on fish. Zebrafish were exposed to HTO from 3 hpf (hours post fertilization) to 96 hpf. The transcriptomic effects were investigated 24 h and 96 h after the beginning of the contamination, using mRNAseq. Results suggested an impact of HTO contamination, regardless of the dose rate, on genes involved in muscle contraction (tnnt2d, tnni2a.4, slc6a1a or atp2a1l) and eye opacity (crygm2d9, crygmxl1, mipb or lim2.3) after 24 h of contamination. Interestingly, an opposite differential expression was highlighted in genes playing a role in muscle contraction and eye opacity in 24 hpf embryos when comparing dose rates, suggesting an onset of DNA protective mechanisms. The expression of h2afx and ddb2 involved in DNA repair was enhanced in response to HTO exposure. The entrainment of circadian clock and the response to H2O2 signalling pathways were enriched at 96 hpf at 0.4 mGy/h and in both stages after 4 mGy/h. Genes involved in ROS scavenging were differentially expressed only after 24 h of exposure for the lowest dose rate, suggesting the onset of early protective mechanisms against oxidative stress. Effects highlighted on muscle at the molecular scale were confirmed at a higher biological scale, as electron microscopy observations revealed sarcomere impairments in 96 hpf larvae for both dose rates. Together with other studies, the present work provides useful data to better understand modes of action of tritium on zebrafish embryos-larvae.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping