ZFIN ID: ZDB-PUB-130710-106
Early dioxin exposure causes toxic effects in adult zebrafish
Baker, T.R., Peterson, R.E., and Heideman, W.
Date: 2013
Source: Toxicological sciences : an official journal of the Society of Toxicology   135(1): 241-50 (Journal)
Registered Authors: Heideman, Warren, Peterson, Richard E.
Keywords: TCDD, dioxin, zebrafish, endocrine disruption, skeletal, reproductive, sexual differentiation, ovary
MeSH Terms:
  • Abnormalities, Drug-Induced
  • Animals
  • Bone and Bones/abnormalities
  • Dose-Response Relationship, Drug
  • Embryonic Development/drug effects*
  • Female
  • Fertility/drug effects
  • Male
  • Ovary/abnormalities
  • Ovary/drug effects
  • Sex Ratio
  • Sexual Development/drug effects*
  • Zebrafish
PubMed: 23811824 Full text @ Toxicol. Sci.

The acute effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure have been well documented in many vertebrate species. However, less is known about the consequences in adulthood from sublethal exposure during development. To address this, we exposed zebrafish to sublethal levels of TCDD (1 h; 50 pg/ml), either in early embryogenesis (day 0) or during sexual determination (3 and 7 weeks), and assessed the effects later in adulthood. We found that exposure during embryogenesis produced few effects on the adults themselves, but did affect the offspring of these fish: malformations and increased mortality were observed in the subsequent generation. Zebrafish exposed during sexual development showed defects as adults in the cranial and axial skeleton. This was most clearly manifested as scoliosis caused by malformation of individual vertebrae. These fish also showed defects in reproduction, producing fewer eggs with lower fertilization success. Both males and females were affected, with males contributing to the decrease in egg release from the females, and exposed females contributing to fertilization failure. TCDD exposure at 3 and 7 weeks produced feminization of the population. Surprisingly, part of this was due to the appearance of fish with clearly female bodies, yet carrying testes in place of ovaries. Our results show that exposures that produce little if any impact during development cause can cause severe consequences during adulthood, and present a model for studying this process.