title: Life-cycle exposure to BDE-47 results in thyroid endocrine disruption to adults and offsprings of zebrafish (Danio rerio).
abstract: 2,2,4',4'-Tetrabromodi-phenyl ether (BDE-47) is predominantly concentrated in humans and wildlife and disturbs thyroid hormone homeostasis. The purpose of this study was to characterize the thyroid endocrine disruption induced by life-cycle exposure to BDE-47 in adults and offspring of zebrafish (Danio rerio). We exposed zebrafish embryos at the blastula stage to different concentrations of BDE-47 (1, 5, and 10μg/L). Exposure duration was 180days until fish reached adulthood. In F0 larvae, exposure decreased survival and increased malformations at 4 dpf. Thyroid hormone concentrations did not differ significantly between the F0 larvae and controls. All exposures significantly up-regulated expression of tshß, pa8, ugt1 and tg and down-regulated ttr. Significant up-regulation of dio2 and crh was observed in the 10μg/L BDE-47 group. There was no significant difference in the growth and somatic index between F0 adults and controls. BDE-47 (10μg/L) significantly decreased whole-body content of thyroxine (T4) but significantly increased triiodothyronine (T3) in both sexes. All exposures up-regulated expression of crh, tshß, pa8, ugt1 and tg and down-regulated ttr. Exposure to 10μg/L BDE-47 significantly up-regulated dio2 and ugt1 in both sexes. BDE-47 exposure (5 and 10μg/L) significantly increased the activity of pethoxy-resorufin-O-deethylase and UDP-glucuronosyl transferase. BDE-47 (10μg/L) significantly increased activity of ethoxy- and methoxy-resorufin-O-deethylase. In F1 offspring without continued BDE-47 (10μg/L) treatment, T4 significantly decreased and T3 increased. T4 was further decreased and T3 was further increased with continued BDE-47 treatment. Continued BDE-47 exposure decreased hatching and increased malformation compared with those without BDE-47 exposure. Expression of crh, tshß, dio2, pa8, ugt1 and tg was significantly up-regulated without BDE-47 exposure and with continued exposure. With continued BDE-47 exposure, dio1 was significantly up-regulated and ttr was significantly down-regulated. All the genes showed clear differences between continued exposure to 10μg/L BDE-47 and without BDE-47 exposure. These results suggest that parental exposure to BDE-47 results in thyroid endocrine disruption in adults and offspring.
authors: College of Environmental Science and Engineering, Jilin Normal University, Haifeng Street, Siping, Tiexi Dist. 136000, China. Electronic address: zhaoxuesong008@163.com.
authors: Xuesong
authors: X
authors: Zhao
authors: College of Environmental Science and Engineering, Jilin Normal University, Haifeng Street, Siping, Tiexi Dist. 136000, China. Electronic address: renxin_hit@126.com.
authors: Xin
authors: X
authors: Ren
authors: College of Environmental Science and Engineering, Jilin Normal University, Haifeng Street, Siping, Tiexi Dist. 136000, China. Electronic address: renbaixiang008@126.com.
authors: Baixiang
authors: B
authors: Ren
authors: College of Environmental Science and Engineering, Jilin Normal University, Haifeng Street, Siping, Tiexi Dist. 136000, China. Electronic address: 158432069@qq.com.
authors: Zhouying
authors: Z
authors: Luo
authors: College of Environmental Science and Engineering, Jilin Normal University, Haifeng Street, Siping, Tiexi Dist. 136000, China. Electronic address: 627993199@qq.com.
authors: Rong
authors: R
authors: Zhu
mesh_terms: D000375:Aging / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000187:drug effects / Q000378:metabolism; D052244:Endocrine Disruptors / Q000633:toxicity*; D015870:Gene Expression / Q000187:drug effects; D055768:Halogenated Diphenyl Ethers / Q000633:toxicity*; D008018:Life Cycle Stages / Q000187:drug effects* / Q000235:genetics; D008099:Liver / Q000187:drug effects / Q000196:embryology / Q000254:growth & development; D013961:Thyroid Gland / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D013963:Thyroid Hormones / Q000097:blood / Q000235:genetics; D015027:Zebrafish / Q000002:abnormalities / Q000196:embryology / Q000254:growth & development*
chemical_list: D052244:Endocrine Disruptors; D055768:Halogenated Diphenyl Ethers; D013963:Thyroid Hormones; C511295:2,2',4,4'-tetrabromodiphenyl ether
keywords: BDE-47; Life-cycle exposure; Thyroid disruption; Zebrafish offsprings