Project description:We evaluated the possible mechanisms by which exposure to a sequentially treated pulp and paper mill effluent affects gene expression in the liver of male and female fathead minnows. Sexually mature fathead minnows were exposed to either river water, which served as our control (C), 10% untreated kraft effluent (UTK), 25% treated kraft effluent (TK) or 100% final effluent (CMO) from a multiprocess pulp and paper mill for 6 days. A total of 4 treatments. Each exposure aquarium consisted of a 42.1 L column that contained individual 5.3 L chambers. Each chamber contained a FHM breeding pair. A total of 3 biological replicates for male and female FHM per treatment were sent for microarray analysis resulting in a total of 24 arrays run as a reference design with a pooled sample of the 6 river water exposed fish serving as the reference sample..
Project description:We investigated the impacts of wastewater effluent exposure on gene expression in adult fathead minnows, a freshwater fish commonly used as an ecotoxicological model.
Project description:We evaluated the possible mechanisms by which exposure to a sequentially treated pulp and paper mill effluent affects gene expression in the liver of male and female fathead minnows.
Project description:The federally endangered Okaloosa darter (Etheostoma okaloosae) is found almost exclusively on the Eglin Air Force Base in the Choctawhatchee Bay watershed of Florida. Portions of this limited habitat are threatened with erosion of soils, altered hydrology, and impaired water quality. One stream reach in particular, East Turkey Creek, has demonstrated potential water quality problems including poor invertebrate bioassessment scores (IBI), uncharacteristically high conductivity values, and low numbers of Okaloosa darters. General water quality (dissolved oxygen, specific conductance, pH, temperature, and relative turbidity and primary productivity) was characterized in both the potentially impacted East Turkey Creek and a reference stream (Long Creek). Water quality was assessed during a 30 day exposure using passive samplers for both non-polar and polar effluent parameters. Metal loading in the system was assessed via fish tissue burdens in resident Pteronotropis hypseleotris. Additionally, microarray analysis was performed on gonad and liver tissue from fathead minnows, Pimephales promelas, after 48-h exposures to water collected from the two creeks and brought into the laboratory. Gene expression changes were evident at the site below the influence of a wastewater spray field sited along East Turkey Creek, suggesting that anthropogenic compounds in the effluent waters may have affected both liver and testis function and could be related to account the general decrease in populations of the Okaloosa darter. Array hybridizations were performed using a single color design. Four biological replicates consisting of four different individuals were analyzed for each of the treatments (University of Florida control, and each of five sites). Site C was left out of subsequent analysis for publication, due to poor characterization of the site. Two Samples were left out of the normalization/analysis due to QC failure. Therefore, there are only 3 replicates of the "testis, site A water, exposed 48 h." and "liver, site E water, exposed 48 h." groups.
Project description:Ab initio gene prediction and evidence alignment were used to produce the first annotations for the fathead minnow (Pimephales promelas) genome. We also describe a genome browser, hosted by the Society of Environmental Toxicology and Chemistry, that provides simplified access to the annotation data in context with the genomic sequence. The present study extends the utility of the fathead minnow genome and supports the continued development of this species as a model organism for predictive toxicology. Environ Toxicol Chem 2017;36:3436-3442. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Project description:Mosquitoes function as important vectors for many diseases globally and can have substantial negative economic, environmental, and health impacts. Specifically, West Nile virus (WNv) is a significant and increasing threat to wildlife populations and human health throughout North America. Mosquito control is an important means of controlling the spread of WNv, as the virus is primarily spread between avian and mosquito vectors. This is of particular concern for avian host species such as the Greater sage-grouse (Centrocercus urophasianus), in which WNv negatively impacts fitness parameters. Most mosquito control methods focus on the larval stages. In North America, control efforts are largely limited to larvicides, which require repeated application and have potentially negative ecological impacts. There are multiple potential advantages to using indigenous fish species as an alternative for larval control including lowered environmental impact, decreased costs in terms of time and financial inputs, and the potential for the establishment of self-sustaining fish populations. We tested the efficacy of using fathead minnows (Pimephales promelas) as biological control for mosquito populations in livestock reservoirs of semiarid rangelands. We introduced minnows into 10 treatment reservoirs and monitored an additional 6 non-treated reservoirs as controls over 3 years. Adult mosquitoes of species known to transmit WNv (e.g., Culex tarsalis) were captured at each site and mosquito larvae were also present at all sites. Stable isotope analysis confirmed that introduced fathead minnows were feeding at the mosquito larvae trophic level in all but one treatment pond. Treatment ponds demonstrated suppressed levels of mosquito larva over each season compared to controls with a model-predicted 114% decrease in larva density within treatment ponds. Minnows established self-sustaining populations throughout the study in all reservoirs that maintained sufficient water levels. Minnow survival was not influenced by water quality. Though minnows did not completely eradicate mosquito larvae, minnows are a promising alternative to controlling mosquito larvae density within reservoirs. We caution that careful site selection is critical to avoid potential negative impacts, but suggest the introduction of fathead minnows in reservoirs can dramatically reduce mosquito larva abundance and potentially help mitigate vector-borne disease transmission.
Project description:A growing number of studies have examined transcriptional responses to sex steroids along the hypothalamic-pituitary-gonadal axis in teleost fishes. However, data are lacking on the molecular cascades that underlie progesterone signaling. The objective of this study was to characterize the transcriptional response in the ovary of fathead minnows (Pimephales promelas) in response to progesterone (P4). Fathead minnow ovaries were exposed in vitro to 500 ng P4/L. Germinal vesicle migration and breakdown (GVBD) was observed and microarrays were used to identify gene cascades affected by P4. Microarray analysis identified 1702 differentially expressed transcripts after P4 treatment. Functional enrichment analysis revealed that transcripts involved in the molecular functions of protein serine/threonine kinase activity, ATP binding, and activity of calcium channels were increased after P4 treatment. There was an overwhelming decrease in levels of transcripts of genes that are structural constituents of ribosomes with P4 treatment. There was also evidence for gene expression changes in steroid and maturation-related transcripts. Pathway analyses identified cell cycle regulation, insulin action, hedgehog, and B cell activation as pathways containing an over-representation of highly regulated transcripts. Significant regulatory sub-networks of P4-mediated transcripts included genes regulated by tumor protein p53 and E2F transcription factor 1. These data provide novel insight into the molecular signaling cascades that underlie P4-signaling in the ovary and identify genes and processes that may indicate premature GVBD due to environmental pollutants that mimic progestins.