title: Development of quantitative RNA biomarkers for detecting dioxin-like and estrogenic pollutants in Costa Rican native fish species.
abstract: Monitoring the environmental impact on native species is crucial for the correct management of tropical ecosystems. The Costa Rican fish Parachromis dovii (Cichlidae) and Poecilia gillii (Poecillidae) were used as sentinel species for freshwater bodies under considerable pressure by intensive agriculture Cichlidae development. Suitable qRT-PCR probes for the quantification of hepatic mRNA levels of two stress-related genes--vitellogen in (estrogenic effects) and cytochrome P4501A(CYP1A, dioxin-like compounds)--for both species were designed and validated in experimental treatments with model effectors (17beta-estradiol and beta-naphtoflavone, respectively), demonstrating their usefulness as markers of exposure to these two kinds of pollutants. Analysis of fish transplanted across pesticide contaminated sites near Palo Verde National Park, Pacific Coast of Costa Rica did show significant changes on hepatic Cyp1A in both species. In P. dovii, Cyp1A levels were enhanced in Barbubal and in the impacted Cabuyo sites in the rainy season whereas in P. gillii fish Cyp1A transcripts were down-regulated differently across rainy and dry seasons. Vitellogen in mRNA levels in P. gillii varied between males and females with males showing always low values which indicated no estrogenic effects. Within females, vitellogenin levels varied over 100,000 fold depending on their maturation stage, further demonstrating the ability of the method to monitor changes (natural or induced) in the reproductive system of the fish.
authors.affiliation: Department of Environmental Chemistry, ID/EA-CSIC, JordiGirona 18, 08034 Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Navarro
authors.affiliation: Central American Institute for Studies on Toxic Substances/Instituto Regional de Estudios en Sustancias Tóxicas (IRET), Universidad Nacional, Campus Omar Dengo, Heredia 86-3000, Costa Rica.
authors.forename: F
authors.initials: F
authors.lastname: Mena
authors.affiliation: Department of Environmental Chemistry, ID/EA-CSIC, JordiGirona 18, 08034 Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Casado
authors.affiliation: Central American Institute for Studies on Toxic Substances/Instituto Regional de Estudios en Sustancias Tóxicas (IRET), Universidad Nacional, Campus Omar Dengo, Heredia 86-3000, Costa Rica.
authors.forename: M
authors.initials: M
authors.lastname: Pinnock
authors.affiliation: Central American Institute for Studies on Toxic Substances/Instituto Regional de Estudios en Sustancias Tóxicas (IRET), Universidad Nacional, Campus Omar Dengo, Heredia 86-3000, Costa Rica.
authors.forename: E
authors.initials: E
authors.lastname: de la Cruz
authors.affiliation: Department of Environmental Chemistry, ID/EA-CSIC, JordiGirona 18, 08034 Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Barata
authors.affiliation: Central American Institute for Studies on Toxic Substances/Instituto Regional de Estudios en Sustancias Tóxicas (IRET), Universidad Nacional, Campus Omar Dengo, Heredia 86-3000, Costa Rica.
authors.forename: B
authors.initials: B
authors.lastname: Piña
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D023681:Cichlids; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics / Q000378:metabolism*; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics / Q000378:metabolism*; D004147:Dioxins / Q000032:analysis; D052244:Endocrine Disruptors / Q000032:analysis; D004784:Environmental Monitoring; D004958:Estradiol; D005260:Female; D008297:Male; D011036:Poecilia; D012313:RNA / Q000378:metabolism; D014819:Vitellogenins / Q000235:genetics / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D019324:beta-Naphthoflavone
chemical_list: D015415:Biomarkers; D004147:Dioxins; D052244:Endocrine Disruptors; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D004958:Estradiol; D019324:beta-Naphthoflavone; D012313:RNA; D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2