Using zebrafish as a model system for studying the transgenerational effects of dioxin.
2,3,7,8 Tetrachlorodibenzo-p-dioxin (TCDD) has been associated with many disease states in humans. A rising concern is that exposure early in life can lead to adult toxicity and toxicity in subsequent generations. Juvenile zebrafish exposed to TCDD (50 pg/ml in water; 1 h exposure) at 3 and 7 weeks post fertilization showed toxicity only later in adulthood. We have maintained the offspring of these exposed F₀ fish to determine whether we could find adverse affects in the next two generations of F₁ and F₂ offspring. TCDD exposure produced a significantly higher female:male ratio in all three generations. Scoliosis-like axial skeleton abnormalities, not normally observed in controls, were present in the F₁ and F₂ generations descended from the treated F₀ founders. Egg release and fertilization success were reduced in the TCDD lineage F₁ and F₂ generations. This reduction in fertility in the TCDD lineage F₂ generation could be attributed to alterations in the F₂ males. Using zebrafish as a model allowed the simultaneous maintenance of different generations with relatively small space and costs. The zebrafish showed clear signs of transgenerational responses persisting into generations never directly exposed to TCDD.
Molecular and Environmental Toxicology Center, and Pharmaceutical Sciences, University of Wisconsin, Madison, Wisconsin 53705-2222.
Tracie R
TR
Baker
Richard E
RE
Peterson
Warren
W
Heideman
D000818:Animals; D004195:Disease Models, Animal; D052244:Endocrine Disruptors / Q000633:toxicity*; D005260:Female; D008297:Male; D009139:Musculoskeletal Abnormalities / Q000139:chemically induced* / Q000196:embryology; D010053:Ovary / Q000187:drug effects / Q000196:embryology / Q000254:growth & development; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D012098:Reproduction / Q000187:drug effects*; D012744:Sex Ratio; D015027:Zebrafish / Q000002:abnormalities / Q000196:embryology / Q000254:growth & development*
D052244:Endocrine Disruptors; D000072317:Polychlorinated Dibenzodioxins
TCDD; dioxin; endocrine disruption; ovary; reproductive; sexual differentiation; skeletal; toxicity; transgenerational; zebrafish