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:Bacteriophage – host dynamics and interactions are important for microbial community composition and ecosystem function. Nonetheless, empirical evidence in engineered environment is scarce. Here, we examined phage and prokaryotic community composition of four anaerobic digestors in full-scale wastewater treatment plants (WWTPs) across China. Despite relatively stable process performance in biogas production, both phage and prokaryotic groups fluctuated monthly over a year of study period. Nonetheless, there were significant correlations in their α- and β-diversities between phage and prokaryotes. Phages explained 40.6% of total prokaryotic community composition, much higher than the explainable power by abiotic factors (14.5%). Consequently, phages were significantly (P<0.010) linked to parameters related to process performance including biogas production and volatile solid concentrations. Association network analyses showed that phage-prokaryote pairs were deeply rooted, and two network modules were exclusively comprised of phages, suggesting a possibility of co-infection. Those results collectively demonstrate phages as a major biotic factor in controlling bacterial composition. Therefore, phages may play a larger role in shaping prokaryotic dynamics and process performance of WWTPs than currently appreciated, enabling reliable prediction of microbial communities across time and space.
Project description:Municipal wastewater effluent can impact its receiving environment. In the St. Lawrence River, male fish living downstream from Montreal exhibit increased hepatic vitellogenin, intersex, delayed spermatogenesis and altered immune function. Few studies have examined genome-wide effects associated with municipal effluent exposure in fish to decipher the mechanisms of toxicity. The present objective was to identify hepatic cellular signaling pathways in fathead minnows following exposure to municipal wastewater effluent. Immature minnows were exposed for 21 days to either 0% (Control) or 20% municipal effluent, the highest concentration in the St. Lawrence River. Hepatic RNA was extracted and used to hybridize a fathead minnow oligonucleotide microarray containing approximately 15K gene sequences.
Project description:Municipal wastewater effluent can impact its receiving environment. In the St. Lawrence River, male fish living downstream from Montreal exhibit increased hepatic vitellogenin, intersex, delayed spermatogenesis and altered immune function. Few studies have examined genome-wide effects associated with municipal effluent exposure in fish to decipher the mechanisms of toxicity. The present objective was to identify hepatic cellular signaling pathways in fathead minnows following exposure to municipal wastewater effluent. Immature minnows were exposed for 21 days to either 0% (Control) or 20% municipal effluent, the highest concentration in the St. Lawrence River. Hepatic RNA was extracted and used to hybridize a fathead minnow oligonucleotide microarray containing approximately 15K gene sequences. Sixteen samples were examined, 8 control samples and 8 exposed samples.
Project description:Rivers containing effluents from water treatment plants are complex soups of compounds, ranging from pharmaceuticals to natural hormones. Male fathead minnows (Pimephales promelas) were exposed for 3 weeks to effluent waters from the Metropolitan Wastewater Treatment Plant in St. Paul, MN. Fish were tested for their competitive nest holding behavior. Changes in vitellogenin were measured and these were correlated to changes in gene expression using a 22,000 gene microarray developed specifically for fathead minnows. Significant changes in gene expression were observed in both liver and gonad, which correlate to phenotypic changes of vitellogenin induction and reduced competitive behavior. We also compared by real-time PCR the expression changes in key genes related to steroid biosynthesis and metabolism in fish exposed to the effluent as well as in fish exposed to a model estrogen and a model androgen. While the gene expression signature from effluent-exposed fish shared some elements with estrogen and androgen signatures, overall it was different, underscoring the complexity of compounds present in sewage and their different modes of action.
Project description:This series represents the gene expression study of phages DT1 and 2972 during the whole process of infection. Gene expression was measured at nine time intervals (0, 2, 7, 12, 17, 22, 27, 32, 37 minutes) during phage infection.