title: Exposure to a PBDE/OH-BDE mixture alters juvenile zebrafish (Danio rerio) development.
abstract: Polybrominated diphenyl ethers (PBDEs) and their metabolites (e.g., hydroxylated BDEs [OH-BDEs]) are contaminants frequently detected together in human tissues and are structurally similar to thyroid hormones. Thyroid hormones partially mediate metamorphic transitions between life stages in zebrafish, making this a critical developmental window that may be vulnerable to chemicals disrupting thyroid signaling. In the present study, zebrafish were exposed to 6-OH-BDE-47 (30 nM; 15 μg/L) alone, or to a low-dose (30 μg/L) or high-dose (600 μg/L) mixture of PentaBDEs, 6-OH-BDE-47 (0.5-6 μg/L), and 2,4,6-tribromophenol (5-100 μg/L) during juvenile development (9-23 d postfertilization) and evaluated for developmental endpoints mediated by thyroid hormone signaling. Fish were sampled at 3 time points and examined for developmental and skeletal morphology, apical thyroid and skeletal gene markers, and modifications in swimming behavior (as adults). Exposure to the high-dose mixture resulted in >85% mortality within 1 wk of exposure, despite being below reported acute toxicity thresholds for individual congeners. The low-dose mixture and 6-OH-BDE-47 groups exhibited reductions in body length and delayed maturation, specifically relating to swim bladder, fin, and pigmentation development. Reduced skeletal ossification was also observed in 6-OH-BDE-47-treated fish. Assessment of thyroid and osteochondral gene regulatory networks demonstrated significantly increased expression of genes that regulate skeletal development and thyroid hormones. Overall, these results indicate that exposures to PBDE/OH-BDE mixtures adversely impact zebrafish maturation during metamorphosis. Environ Toxicol Chem 2017;36:36-48. © 2016 SETAC.
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Macaulay
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Chernick
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.
authors.forename: Albert
authors.initials: A
authors.lastname: Chen
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Hinton
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Jordan M
authors.initials: JM
authors.lastname: Bailey
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA.
authors.forename: Seth W
authors.initials: SW
authors.lastname: Kullman
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.|Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Edward D
authors.initials: ED
authors.lastname: Levin
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Stapleton
mesh_terms: D000328:Adult; D000818:Animals; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism / Q000633:toxicity*; D006801:Humans; D010012:Osteogenesis / Q000187:drug effects* / Q000235:genetics; D011075:Polybrominated Biphenyls / Q000378:metabolism / Q000633:toxicity*; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism; D013963:Thyroid Hormones / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: C580599:6-OH-BDE-47; D055768:Halogenated Diphenyl Ethers; D011075:Polybrominated Biphenyls; D013963:Thyroid Hormones; C086401:pentabromodiphenyl ether
keywords: Development; Juvenile; Mixture; Polybrominated diphenyl ether (PBDE); Zebrafish