title: Regulation of vitellogenin (vtg1) and estrogen receptor (er) gene expression in zebrafish (Danio rerio) following the administration of Cd²⁺ and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
abstract: We evaluated the individual and joint estrogenic effects of cadmium (Cd(2+)) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the zebrafish liver (ZFL) cell line, zebrafish embryo, larvae and the liver of adult zebrafish. The mRNA expression of vtg1 was inhibited by Cd(2+), but unaffected by TCDD in ZFL cells. Similar changes in the mRNA levels of ERα, ERβ1, ERβ2 and GPER (G protein coupled estrogen receptor) in ZFL cells were also observed. Deletion mutants of vtg1 gene promoters were constructed to investigate transcriptional regulation, and we found that all of the constructs failed to respond to TCDD or Cd(2+). However, after co-transfection with a vtg1 promoter-luciferase construct to the ERα, ERβ1, ERβ2 and GPER expression vectors, decreased luciferase activity was observed in the ERα co-transfection group after treatment with Cd(2+), suggesting that ERα participates in vtg1 transcriptional regulation and is affected by Cd(2+). Differences in the regulation of the mRNA levels of these genes were also observed between different developmental stages and between the livers of male and female zebrafish.
authors.affiliation: School of Life Sciences, Chinese University, Sha Tin, Hong Kong SAR, China.
authors.forename: Ying Ying
authors.initials: YY
authors.lastname: Chen
authors.affiliation: School of Life Sciences, Chinese University, Sha Tin, Hong Kong SAR, China. Electronic address: kingchan@cuhk.edu.hk.
authors.forename: King Ming
authors.initials: KM
authors.lastname: Chan
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D002460:Cell Line; D004625:Embryo, Nonmammalian; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D007814:Larva; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics*; D014819:Vitellogenins / Q000235:genetics*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics
chemical_list: D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D014819:Vitellogenins; D029961:Zebrafish Proteins; D002104:Cadmium
keywords: Biomarkers; Environmental estrogen; Reporter gene system