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:The widespread occurrence of psychoactive pollutants in surface waters raises concerns for aquatic ecosystems, yet impacts beyond behavioral disruption remain poorly understood. Designed to target neurotransmitter (NT) systems in humans, these contaminants may also interfere with conserved NT pathways in fish. Here we provide the first evidence that fish sperm contain NTs and their receptors, indicating an active NT-mediated signaling system essential for sperm function. Using European perch (Perca fluviatilis) exposed to environmentally relevant concentrations of methamphetamine, we quantified NTs in brain, gonads, and sperm, assessed tissue-specific bioaccumulation, and evaluated sperm performance. Methamphetamine accumulated across tissues, modified NT profiles, and altered sperm motility and velocity. These findings reveal a previously unrecognized pathway of reproductive vulnerability, identifying NT signaling in sperm as a novel target of psychoactive pollutants with potential implications for fertilization success and population resilience in aquatic ecosystems.
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:Epoxiconazole (EPO) and fludioxonil (FLU) are fluorinated fungicides characterized by their extremely high environmental persistence and ecotoxicity. Given their decades-old use in the agrochemical sector, EPO and FLU have become frequent pollutants of terrestrial and aquatic ecosystems. And yet, not much is known regarding how these pesticides biodegrade in the natural environment and/or how to develop suitable bioremediation approaches capable of tackling their inherent recalcitrance. As a result, this work focused on providing new insights into the bacterial degradation of EPO and FLU, by surveying the catabolic activity of a previously obtained EPO-enriched bacterial consortium through chemical and metaproteogenomic analyses guided by different metabolic modelling tools. The bacterial consortium was capable of extensively degrading EPO and FLU in 21 days, with fungicide removals of over 90 % and defluorination efficiencies of 55 to 80 %, but none of the subproducts predicted for either pesticide were identified by ESI-LC-MS/MS. Despite this, the combination of metabolic modelling tools and metaproteogenomic surveys suggested that EPO and FLU were first attacked in their N-heterocyclic moieties and that the targets of defluorination were the resulting aromatic fluorinated intermediates. This catabolic cascade is consistent with the experimental data gathered in this study and with the existing literature on this topic. Also, the degrading consortium remained surprisingly stable at the taxonomical and functional levels, highlighting its catabolic plasticity in biodegrading and defluorinating two chemically distinct fluorinated compounds. This work offers a conceptual framework with novel observations that can guide future efforts to further elucidate the pathways of microbial transformation of these pesticides, ultimately contributing for better environmental risk management practices for these pollutants.
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:A short-term microcosm experiment was conducted to evaluate the impact of wastewater discharge on coastal microbial communities. Coastal seawater was exposed to two types of treated wastewater: (i) unfiltered wastewater, containing nutrients, pollutants, and allochthonous microbes, and (ii) filtered wastewater, which retained only nutrients and pollutants while removing microbial components. Metaproteomic samples were collected from the coastal seawater prior to the experiment and from each experimental flask at the late exponential growth phase to assess microbial functional responses to wastewater exposure.
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: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