ABSTRACT: Fast decay of human-associated antibiotic resistance and long-term maintenance of the environmental resistome in anthropogenically-impacted aquatic ecosystems
Project description:Imposex, the superimposition of male sexual characteristics in females, is caused by tributyltin (TBT) and provides one of the best ecological examples of anthropogenically-induced endocrine disruption in aquatic ecosystems. We used combinations of 454 Roche pyrosequencing and microarray technologies to understand the functional genomic basis of imposex in the prosobranch gastropod, Nucella lapillus, a recognised sentinel for TBT-induced imposex.
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 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.
2018-08-28 | GSE104933 | GEO
Project description:Exploring the Aquatic Resistome
