PUBLICATION

Comparative thyroid disruption by o,p'-DDT and p,p'-DDE in zebrafish embryos/larvae

Authors
Wu, L., Ru, H., Ni, Z., Zhang, X., Xie, H., Yao, F., Zhang, H., Li, Y., Zhong, L.
ID
ZDB-PUB-190914-11
Date
2019
Source
Aquatic toxicology (Amsterdam, Netherlands)   216: 105280 (Journal)
Registered Authors
Keywords
DDE, DDTs, Hypothalamic-pituitary-thyroid axis, Thyroid disruption
MeSH Terms
  • Animals
  • DDT/toxicity*
  • Dichlorodiphenyl Dichloroethylene/toxicity*
  • Embryo, Nonmammalian/drug effects*
  • Embryo, Nonmammalian/metabolism
  • Gene Expression Regulation, Developmental/drug effects
  • Larva/anatomy & histology
  • Larva/drug effects
  • Larva/metabolism
  • Thyroid Gland/drug effects
  • Thyroid Gland/metabolism
  • Thyroid Gland/pathology*
  • Water Pollutants, Chemical/toxicity
  • Zebrafish/embryology*
  • Zebrafish/genetics
PubMed
31518776 Full text @ Aquat. Toxicol.
CTD
31518776
Abstract
1,1-Trichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl) ethane (o,p'-DDT) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) cause thyroid disruption, but the underlying mechanisms of these disturbances in fish remain unclear. To explore the potential mechanisms of thyroid dysfunction caused by o,p'-DDT and p,p'-DDE, thyroid hormone and gene expression levels in the hypothalamic-pituitary-thyroid (HPT) axis were measured, and the developmental toxicity were recorded in zebrafish larvae. Zebrafish embryos/larvae were exposed to o,p'-DDT (0, 0.28, 2.8, and 28 nM; or 0, 0.1, 1, and 10 μg/L) and p,p'-DDE (0, 1.57, 15.7, and 157 nM; or 0, 0.5, 5, and 50 μg/L) for 7 days. The genes related to thyroid hormone synthesis (crh, tshβ, tg, nis and tpo) and thyroid development (nkx2.1 and pax8) were up-regulated in both the o,p'-DDT and p,p'-DDE exposure groups. Zebrafish embryos/larvae exposed to o,p'-DDT showed significantly increased total whole-body T4 and T3 levels, with the expression of ugt1ab and dio3 being significantly down-regulated. However, the p,p'-DDE exposure groups showed significantly lowered whole-body total T4 and T3 levels, which were associated with up-regulation and down-regulation expression of the expression of dio2 and ugt1ab, respectively. Interestingly, the ratio of T3 to T4 was significantly decreased in the o,p'-DDT (28 nM) and p,p'-DDE (157 nM) exposure groups, suggesting an impairment of thyroid function. In addition, reduced survival rates and body lengths and increased malformation rates were recorded after treatment with either o,p'-DDT or p,p'-DDE. In summary, our study indicates that the disruption of thyroid states was different in response to o,p'-DDT and p,p'-DDE exposure in zebrafish larvae.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping