title: Exposure to difenoconazole causes changes of thyroid hormone and gene expression levels in zebrafish larvae.
abstract: Difenoconazole was believed to induce a large suite of symptoms during zebrafish development, but little is known about the negative invisible effect known as endocrine disruption. In this study, zebrafish (Danio rerio) embryos were exposed to various concentrations of difenoconazole from fertilization to 120 h post-fertilization (hpf), and the whole body content of thyroid hormone and gene transcription in the hypothalamic-pituitary-thyroid (HPT) axis were investigated. Results showed thyroxine (T4) levels were significantly decreased, while triiodothyronine (T3) concentrations were not changed. Moreover, the mRNA transcription of corticotrophin-releasing hormone (crh), thyroid-stimulating hormone (tshβ), transthyretin (ttr), thyronine deiodinase (dio1 and dio2), uridine diphosphate glucuronosyltransferase (ugt1ab) in the HPT axis were significantly up-regulated, but the transcriptions of thyroglobulin (tg), sodium/iodide symporter (nis) and thyroid hormone receptors trβ were not changed. The overall results showed that exposure to difenoconazole could alter thyroid hormone levels and gene transcription in zebrafish larvae, indicating thyroid endocrine disruption.
authors.affiliation: Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, PR China. Electronic address: liangxiaozju@126.com.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liang
authors.affiliation: Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, PR China; Key Lab of Sustainable Utilization of Technology Research for Fishery Resource of Zhejiang Province, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316021, PR China. Electronic address: xjyuliang@163.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Yu
authors.affiliation: Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, PR China. Electronic address: guiwj@zju.edu.cn.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Gui
authors.affiliation: Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, PR China. Electronic address: zhugn@zju.edu.cn.
authors.forename: Guonian
authors.initials: G
authors.lastname: Zhu
mesh_terms: D000818:Animals; D004148:Dioxolanes / Q000494:pharmacology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D008297:Male; D013974:Thyroxine / Q000378:metabolism*; D014230:Triazoles / Q000494:pharmacology*; D015854:Up-Regulation; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics*
chemical_list: D004148:Dioxolanes; D014230:Triazoles; D029961:Zebrafish Proteins; C115058:difenoconazole; D013974:Thyroxine
keywords: Difenoconazole; Gene expression; Hypothalamic–pituitary–thyroid axis; Thyroid hormone; Zebrafish larvae