PUBLICATION

Aryl hydrocarbon receptor 2 mediates the toxicity of Paclobutrazol on the digestive system of zebrafish embryos

Authors
Wang, W.D., Chen, G.T., Hsu, H.J., Wu, C.Y.
ID
ZDB-PUB-141217-20
Date
2015
Source
Aquatic toxicology (Amsterdam, Netherlands)   159C: 13-22 (Journal)
Registered Authors
Keywords
Aryl hydrocarbon receptor, Cyp1a1, Digestive organs, Paclobutrazol, Zebrafish
MeSH Terms
  • Animals
  • Cytochrome P-450 CYP1A1/genetics
  • Digestive System/drug effects*
  • Digestive System/embryology
  • Embryo, Nonmammalian/drug effects
  • Embryonic Development/drug effects
  • Fungicides, Industrial/toxicity
  • Gene Expression Regulation, Developmental/drug effects
  • Gene Knockdown Techniques
  • Receptors, Aryl Hydrocarbon/genetics
  • Receptors, Aryl Hydrocarbon/metabolism*
  • Triazoles/toxicity*
  • Water Pollutants, Chemical/toxicity
  • Zebrafish/genetics*
  • Zebrafish/metabolism
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed
25500619 Full text @ Aquat. Toxicol.
Abstract
Paclobutrazol (PBZ), a trazole-containing fungicide and plant growth retardant, has been widely used for over 30 years to regulate plant growth and promote early fruit setting. Long-term usage of PBZ in agriculture and natural environments has resulted in residual PBZ in the soil and water. Chronic exposure to waterborne PBZ can cause various physiological effects in fish, including hepatic steatosis, antioxidant activity, and disruption of spermatogenesis. We have previously shown that PBZ also affects the rates of zebrafish embryonic survival and hatching, and causes developmental failure of the head skeleton and eyes; here, we further show that PBZ has embryonic toxic effects on digestive organs of zebrafish, and describe the underlying mechanisms. PBZ treatment of embryos resulted in dose-dependent morphological and functional abnormalities of the digestive organs. Real-time RT-PCR and in situ hybridization were used to show that PBZ strongly induces cyp1a1 expression in the digestive system, and slightly induces ahr2 expression in zebrafish embryos. Knockdown of ahr2 with morpholino oligonucleotides prevents PBZ toxicity. Thus, the toxic effect of PBZ on digestive organs is mediated by AhR2, as was previously reported for retene and TCDD. These findings have implications for understanding the potential toxicity of PBZ during embryogenesis, and thus the potential impact of fungicides on public health and the environment.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping