Project description:Major classes of hormone mimics that have been studied include environmental estrogens and androgens, but recent studies have also demonstrated the significant impacts of natural and synthetic progesterones in the environment. The objective of this study was to evaluate the molecular and physiological impacts of progestin, anti-progestin, and mixture exposures in the Eastern Mosquitofish (G. holbrooki). By comparison of gene expression profiles and modulated biological processes in the three groups, it was determined that mifepristone acts more as a progestin than as an anti-progestin, as has also been demonstrated in other species of fish. This work contributes to the overall knowledge of the impacts of this class of chemical contaminats on aquatic organisms, which are a sentinel species for pollutants as aquatic ecosystems often become a reservoir for anthropogenic contaminants.
Project description:Toxic chemical contaminants have variety of detrimental effects on various species and the impact of pollutants on ecosystems has become an urgent issue. However, very limited species have been examined to date and those studies are mainly limited to vertebrates. In this study, we aimed to establish an ecotoxicogenomic bases for Daphnia magna. Based on a daphnia EST database, we made oligonucleotide-based DNA microarray that has high reproducibility. The DNA microarray was applied to evaluate gene expression profiles of daphnid exposed to chemicals. Characteristic gene expression patterns depending on chemicals indicate that the Daphnia microarray can be used for mechanistic understanding of chemical toxicity. Although acute toxicity test or reproductive toxicity test can provide hazardous concentrations of chemicals, they give no information about mode of action. Our study can be a breakthrough for the evaluation of chemical toxicity on environmental organisms. Keywords: Chemical response
Project description:The increase in human population and urbanization are resulting in an increase in the volume of wastewater and urban runoff effluents entering natural ecosystems. These effluents may contain multiple pollutants to which the biological response of aquatic organisms is still poorly understood mainly due to mixture toxicity and interactions with other environmental factors. In this context, RNA sequencing was used to assess the impact of a chronic exposure to wastewater treatment plant and stormwater effluents at the whole-transcriptome level and evaluate the potential physiological outcomes in the Asian clam Corbicula fluminea. We de-novo assembled a transcriptome from C. fluminea digestive gland and identified a set of 3,181 transcripts with altered abundance in response to water quality. The largest differences in transcriptomic profiles were observed between C. fluminea from the reference site and those exposed to wastewater treatment plant effluents. On both anthropogenically impacted sites, most differentially expressed transcripts were involved in signaling pathways in relation to energy metabolism such as mTOR and FoxO, suggesting an energy/nutrient deficit and hypoxic conditions. These conditions were likely responsible for damages to proteins and transcripts in response to wastewater treatment effluents whereas exposure to urban runoff might result in immune and endocrine disruptions. In absence of comprehensive chemical characterization, the RNAseq approach could provide information regarding the mode of action of pollutants and then be useful for the identification of which parameters must be studied at higher integration level in order to diagnose sites where the presence of complex and variable mixtures of chemicals is suspected.
Project description:CdSe nanoparticles (CdSe NPs) are extensively used in the industry of renewable energies and it is regrettably expectedthat these pollutants will sometime soon appear in marine environmentthrough surface runoff, urban effluents and rivers. Bacteria living in estuarine and coastal sediments will be among the first targets of these new pollutants. The pseudomonads are frequently encountered in these ecosystems. They are involved in several biogeochemical cycles and are known for their high resistance to pollutants. Consequently, this study focussing on the effect of CdSe NPs on the marine strain P. fluorescensBA3SM1 is highly relevant for a number of reasons. First, it aims at improving knowledge about the interactions between bacteria and NPs. This is fundamental to use effectively NPs against pathogenic bacteria. Secondly, this study shows that CdSe NPs of 8 nm in diameter cause a decrease in the secretion of siderophorepyoverdine, a secondary metabolite having a key role in microbial ecology and also employed as a virulence factor in human pathogenic strains such as P. aeruginosa. Consequently, this study highlights that CdSe NPs can have an impact on secondary metabolism of bacteria with environmental and medical implications.
Project description:Major classes of hormone mimics that have been studied include environmental estrogens and androgens, but recent studies have also demonstrated the significant impacts of natural and synthetic progesterones in the environment. The objective of this study was to evaluate the molecular and physiological impacts of progestin, anti-progestin, and mixture exposures in the Eastern Mosquitofish (G. holbrooki). By comparison of gene expression profiles and modulated biological processes in the three groups, it was determined that mifepristone acts more as a progestin than as an anti-progestin, as has also been demonstrated in other species of fish. This work contributes to the overall knowledge of the impacts of this class of chemical contaminats on aquatic organisms, which are a sentinel species for pollutants as aquatic ecosystems often become a reservoir for anthropogenic contaminants. G. holbrooki adult males and females were exposed to one of the following conditions: vehicle control (ethanol), 100 ng/L of levonorgestrel, 100 ng/L of mifepristone, or a mixture of both levonorgestrel and mifepristone. All exposures were conducted for 48 hours with water changed and chemicals renewed daily. Fish were anesthetized using 100 mg/L Benzocaine (Ethyl 4-aminobenzoate). Livers were removed and stored in RNAlater (Qiagen, Hilden, Germany) overnight at 4 C before storage at -80 C. RNA was isolated from the livers using TRIzol (Invitrogen, Grand Island, USA), hydrated using RNAsecure (Ambion, Grand Island, USA), and DNase treated using the Turbo DNA-free kit (Ambion, Grand Island, USA). Four oocyte-development stage-matched RNA samples per treatment were evaluated for RNA integrity using the 2100 BioAnalyzer (Agilent, Santa Clara, USA). The range of RIN values was 8.2-9.6
Project description:Contaminants of Emerging Concern (CECs) can be measured in waters across the United States, including the tributaries of the Great Lakes. The extent to which these contaminants affect gene expression in aquatic wildlife is unclear. This dataset presents the full hepatic transcriptomes of laboratory reared fathead minnows (Pimephales promelas) caged at multiple sites within the Milwaukee Estuary area of concern and control sites. Following 4 days of in situ exposure, liver tissue was removed from males at each site for RNA extraction and sequencing, yielding a total of 116 samples from which libraries were prepared, pooled, and sequenced. For each exposure site, 179 chemical analytes were also assessed. These data were created with the intention of inviting research on possible transcriptomic changes observed in aquatic species exposed to CECs. Access to both full sequencing reads of animal samples as well as water contaminant data across multiple Great Lakes sites will allow others to explore the health of these ecosystems, in support of the aims of the Great Lakes Restoration Initiative.
Project description:Despite the fact that we are constantly exposed to various environmental compounds, very few studies explore the impact of combined exposure to physical and chemical pollutants on reproductive health. Until now, assessment of pollutants is mostly based on the evaluation of single pollutant or combination of chemicals with common features and modes of action. In this context, numerous studies have demonstrated that steroidogenesis and gametogenesis, the main testicular functions, are well-known to be sensitize by endocrine disruptors (as Bisphenol A) and DNA-damaging agents (as γ-rays) respectively. In this study, we aim to investigate short and long term testicular transcriptionnal alterations of combined fetal exposure to well-known environmental toxicants: γ-rays (RAD) and BPA. To discriminate specific signatures of BPA or RAD exposure after combined exposure and evidence the type of synergisms between this pollutants, we performed transcriptomic analyses on testis exposed to BPA or RAD alone and co-exposed with BPA and RAD and compared gene expression with control condition. For this, we exposed pregnant mice from 10.5 dpc to 18.5 dpc to 10µM of BPA (in drinking water) and/or we irradiated mice at 12.5 dpc to 0.2 Gy. We performed transcriptomic analyses on fetal testis (18.5 dpc) and adult testis (3 months) to evaluate short and long term cell response after in utero exposure.
Project description:Microplastics represent a growing environmental concern for the oceans due to their potential capability to adsorb different classes of pollutants, thus representing a still unexplored source of exposure for aquatic organisms. In this study polystyrene (PS) microplastics were characterized for their capability to adsorb pyrene (PYR) as model compound for polycyclic aromatic hydrocarbons, and transfer this chemical to filter feeding mussels Mytilus galloprovincialis. Gene expression analyses of Mytilus galloprovincialis exposed to polystyrene (PS) microplastics and to polystyrene contaminated with pyrene (PS-PYR) have been performed trough a DNA microarray platform.
2014-12-27 | GSE57460 | GEO
Project description:Exploring the Aquatic Resistome