Project description:To investigate gene expression changes in fish by the secondary effluent (directly released to environment) of a waterwater treatment plant in Tucson, Arizona, zebrafish larvae with 5-day exposure to the original (1x) or half (0.5x) concentration of the effluent were analyzed using Agilent G2519F-026437 Zebrafish Oligo Microarray.
Project description:Despite recent knowledge of the potential environmental impact that compounds present in municipal wastewater effluents, including contaminants of emerging concern (CECs), may have, the implications of fish exposure to this contaminant mixtures are not completely understood. The effects caused by effluent CECs may be subtle and diverse, thus the need for sensitive and comprehensive tools such as gene expression to detect such responses. In this study, we conducted laboratory exposures that examined plasma concentrations of vitellogenin (VTG), changes in secondary sexual characteristics and gene expression in sexually mature male fathead minnows (Pimephales promelas) exposed to environmentally realistic (0.5%) and higher (5%) concentrations of municipal wastewater effluents. Secondary and primary treated effluents were used. Several of the 32 CECs investigated were detected, including pharmaceuticals, personal care products, hormones, current use pesticides and industrial compounds. The percent of males with detectable levels of VTG was higher in fish exposed to effluent treatments. An increased number of males with changes in secondary sexual characteristics (e.g. development of ovipositors), was observed in fish exposed to 5% effluent treatments. Gene expression data indicated that overall expression patterns were characteristic to each effluent. Higher numbers of differentially expressed genes were observed in fish exposed to primary treated effluent when compared to controls. Differentially expressed genes belonged to several functional categories, including xenobiotic metabolism, estogenicity and energy/metabolism processes. Gene expression data provided information to understand some of the mechanisms behind the effects observed at higher biological levels. To investigate gene expression responses resulting from exposure to POTW effluents, two laboratory experiments were conducted using effluent from San Diego (Point Loma; SD) and Los Angeles (Hyperion; LA). The LA effluent received secondary treatment and the SD effluent received advanced primary treatment. Treatments used during exposures consisted of negative controls (moderately hard water), positive controls (E2), and 0.5% and 5% effluent concentrations. The 0.5% concentration of effluent represented an environmentally realistic exposure level. The 5% effluent concentration represented a higher level at which we expected biological responses. The exposures lasted 14 days. Treatments: EFFHa = 5% primary treated effluent EFFHb = 5% secondary treated effluent EFFLa = 0.5% primary treated effluent E2a = Estradiol, positive control for primary effluent E2b = Estradiol, positive control for secondary effluent CTRLa = Moderately hard water, negative control for primary effluent CTRLb = Moderately hard water, negative control for secondary effluent
Project description:Our study makes use of zebrafish and has determined hepatic transcriptional changes after exposure to four single pharmaceuticals, a pharmaceutical mixture (MIX), and wastewater effluent (WWE) exposures. The pharmaceuticals chosen include acetaminophen, carbamazepine, gemfibrozil, and venlafaxine. We have performed chronic (6 week), low concentration (0.5 and 10 μgL-1 or 5 and 25% effluent) exposure of male and female fish and previously determined a range of effects (reproductive, histological, hormonal) after exposure to single compounds, a mixture of these compounds or wastewater effluent. Herein we determine by microarray the hepatic transcriptional responses of male and female zebrafish from the same exposures.
Project description:Tritium is an ubiquist radionuclide which can be found in the environment due to natural and anthropogenic activities, particularly in aquatic ecosystems. In this context, tritium effects on aquatic species such as fish have to be characterized. HTO (tritiated water) effects were therefore investigated in zebrafish, Danio rerio, a common model in toxicology and ecotoxicology with a fully sequenced genome. Experiments were conducted on early life stages. Larvae were exposed to 0.4 and 4 mGy/h of HTO until 10 days post fertilization. Tritium internalization was quantified and effects were investigated using a proteomic analysis. The global analysis of the proteome was performed after protein extraction at 7 and 10 dpf on zebrafish eggs exposed from 3 hpf to 10 dpf.
Project description:Mitochondrial dysfunction, disruption of F-actin polymerization, and transcriptomic alterations in zebrafish larvae exposed to trichloroethylene