Host: The Japanese Society of Toxicology
Dioxin pollutants are environmental persistent organic pollutants (POPs), which remain in trace amounts in rivers and silts. Dioxin poses a potential threat to aquatic animals from a raised temperature. In this study, Tg (CYP1A: mCherry) transgenic zebrafish was used as a model animal to compare the toxicity caused by tetrachlorodibenzo-p-dioxin (TCDD) in zebrafish embryos at 26 ℃ and 30 ℃. Zebrafish embryos were exposed to TCDD (0.1, 03, and 1 ppb) or DMSO (control) from 2 to 4 hours after fertilization (4 hpf), until the observation. Comparing the mortality of zebrafish embryos caused by TCDD under the two temperature conditions, there was no significant difference. Whether it is 26 ℃ or 30 ℃, 1ppbTCDD caused pericardial edema in zebrafish embryos at 96 hpf, the ratio of pericardial edema area to body length was 0.3 and 0.48, respectively (P < 0.05). At 96 hpf, the fluorescence intensity of Tg (CYP1A: mCherry) transgenic zebrafish induced by TCDD at 30 ℃ was significantly higher that than induced by TCDD at 26 ℃. Furthermore, we also quantified CYP1A mRNA expression by RT-qPCR, the results showed that the TCDD induced CYP1A mRNA expression at 30 ℃ was significantly higher than TCDD caused expression at 26 ℃. At the same time, the expression of lipid metabolism relative genes ppar- α, ppar- γ, acadm, fasn and slc2a2 also increased by 1ppb TCDD exposure. The results show that the increase of temperature enhances the toxic effect of TCDD on zebrafish embryos, and we will further study its mechanism.
Keywords：TCDD; Ambient temperature; cyp1a; Zebrafish embryo; Lipid metabolism
