title: Characterization of a bystander effect induced by the endocrine-disrupting chemical 6-propyl-2-thiouracil in zebrafish embryos.
abstract: This study was conducted to evaluate possible bystander effects induced by the model chemical 6-propyl-2-thiouracil (PTU) on melanin synthesis. Zebrafish (Danio rerio) embryos were treated with PTU by either microinjection exposure, via waterborne exposure or indirectly through bystander exposure. Melanin content, related mRNA and protein expression were examined at the end of exposure (36 h post-fertilization). Direct exposure to PTU decreased the melanin content, up-regulated mRNA expressions of oculocutaneous albinism type 2 (OCA2), tyrosinase (TYR), dopachrometautomerase (DCT), tyrosinase-related protein 1 (TYRP1) and silver (SILV), and increased the protein expressions of TYR and SILV. Bystander exposure also up-regulated mRNA and protein expressions of TYR and SILV but increased melanin contents. Correlation analysis demonstrated that mRNA expressions of OCA2, TYR, DCT, TYRP1, SILV and protein expressions of TYR and SILV in bystander exposure groups were positively correlated with corresponding expressions in microinjection exposure groups. The results might have environmental implications and highlight the need to consider the bystander effects when assessing potential risks of endocrine-disrupting chemicals.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse & School of the Environment, Nanjing University, Nanjing, China.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Institute of Agricultural Quality Standards & Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, Hubei, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Bingsheng
authors.initials: B
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Yongyong
authors.initials: Y
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse & School of the Environment, Nanjing University, Nanjing, China.
authors.forename: Hongling
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse & School of the Environment, Nanjing University, Nanjing, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Canada; Department of Biology & Chemistry and State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, SAR, China.
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Jianghua
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; College of Fisheries, Huazhong Agricultural University, Wuhan, PR China. Electronic address: ligy2001@163.com.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse & School of the Environment, Nanjing University, Nanjing, China. Electronic address: zhangxw@nju.edu.cn.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhang
mesh_terms: D016115:Albinism, Oculocutaneous / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D024201:Bystander Effect; D004625:Embryo, Nonmammalian / Q000187:drug effects; D052244:Endocrine Disruptors / Q000494:pharmacology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008543:Melanins / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases; D011441:Propylthiouracil / Q000494:pharmacology*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D052244:Endocrine Disruptors; D008543:Melanins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D029961:Zebrafish Proteins; D011441:Propylthiouracil; D010088:Oxidoreductases; C547074:Tyrp1b protein, zebrafish; D014442:Monophenol Monooxygenase