title: Microarray analysis in the zebrafish (Danio rerio) liver and telencephalon after exposure to low concentration of 17alpha-ethinylestradiol.
abstract: 17alpha-ethinylestradiol (EE2) is detected in sewage effluent at concentrations that can disrupt normal reproductive function in fish. The objectives of this study were to identify novel genomic responses to EE2 exposure using microarray and real-time RT-PCR analysis in the liver and telencephalon of male zebrafish. Zebrafish were exposed to an environmentally relevant nominal concentration of 10ng/L EE2 for a 21-day period. In the liver, common biomarkers for estrogenic exposure such as vitellogenin 1 and 3 (vtg1; vtg3), estrogen receptor alpha (esr1), and apolipoprotein A1 (apoA1) mRNA were identified by microarray analysis as being differentially regulated. Real-time RT-PCR confirmed that vtg1 was induced approximately 700-fold, vtg3 was induced approximately 100-fold and esr1 was induced approximately 20-fold. As determined by microarray analysis, ATPase Na+/K+ alpha 1a.4 (atp1a1a.4) and ATPase Na+/K+ beta 1a (atp1b1a) mRNA were down-regulated in the liver. Gene ontology (GO) analysis revealed that there were common biological processes and molecular functions regulated by EE2 in both tissues (e.g. electron transport and cell communication) but there were tissue specific changes in gene categories. For example, genes involved in protein metabolism, carbohydrate metabolism were down-regulated in the liver but were induced in the telencephalon. This study demonstrates that (1) tissues exhibit different gene responses to low EE2 exposure; (2) there are pronounced genomic effects in the liver and (3) multi-tissue gene profiling is needed to improve understanding of the effects of human pharmaceuticals on aquatic organisms.
authors.affiliation: Centre for Advanced Research in Environmental Genomics, 30 Marie Curie, Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Martyniuk
authors.forename: Emily R
authors.initials: ER
authors.lastname: Gerrie
authors.forename: Jason T
authors.initials: JT
authors.lastname: Popesku
authors.forename: Marc
authors.initials: M
authors.lastname: Ekker
authors.forename: Vance L
authors.initials: VL
authors.lastname: Trudeau
mesh_terms: D000818:Animals; D016632:Apolipoprotein A-I / Q000096:biosynthesis / Q000235:genetics; D047628:Estrogen Receptor alpha / Q000096:biosynthesis / Q000235:genetics; D004997:Ethinyl Estradiol / Q000633:toxicity*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000254:Sodium-Potassium-Exchanging ATPase / Q000096:biosynthesis / Q000235:genetics; D013687:Telencephalon / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D014819:Vitellogenins / Q000096:biosynthesis / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029961:Zebrafish Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D016632:Apolipoprotein A-I; D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D029961:Zebrafish Proteins; C000594789:estrogen receptor 1, zebrafish; D004997:Ethinyl Estradiol; D000254:Sodium-Potassium-Exchanging ATPase