ABSTRACT: Responses of stream microbes to multiple anthropogenic stressors (salinization, fine sediment deposition and altered flow) in a mesocosm study
Project description:Responses of prokaryotic stream microbes to multiple anthropogenic stressors in a mesocosm study
| PRJNA416457 | ENA
Project description:Appalachian stream leaf litter microbiota under salinization
| PRJNA484970 | ENA
Project description:DNA metabarcoding improves the detection of multiple stressor responses of stream invertebrates to increased salinity, fine sediment deposition and reduced flow velocity
Project description:To test whether elevated CO2 , which drives seawater below pH 7.9, would shift the dynamical expression patterns diatoms in a more natural environment, we designed a controlled mesocosm study at Friday Harbor Laboratories (FHL) Ocean Acidification Environmental Laboratory (OAEL). Briefly, four independent mesocosm tanks were set up with continuous flow (10-12 mL/min) of filtered seawater from the Puget Sound to simulate mid-century (pH 7.9) and acidified oceanic conditions (pH 7.6) in duplicate. Mesocosm reservoirs were supplemented with nutrients and inoculated with T. pseudonana acclimated in FHL seawater. Mesocosms were outfitted with custom enclosures to simulate a 12:12 light:dark diel cycle. Cells for RNA extraction were sampled in the middle of the light and dark cycle and sequenced on Illumina NextSeq 500 platform.
Project description:Freshwater salinization poses global challenges for aquatic organisms inhabiting urban streams, impacting their physiology and ecology. However, current salinization research predominantly focuses on mortality endpoints in limited model species, overlooking the sublethal effects on a broader spectrum of organisms and the exploration of adaptive mechanisms and pathways under natural field conditions. To address these gaps, we conducted high-throughput sequencing transcriptomic analysis on the gill tissue of the euryhaline fish Gasterosteus aculeatus, investigating its molecular response to salinity stress in the highly urbanized river Boye, Germany. We found that in stream sections with sublethal concentrations of chloride costly osmoregulatory systems were activated, evidenced by the differential expression of genes related to osmoregulation. Our enrichment analysis revealed differentially expressed genes (DEGs) related to transmembrane transport and regulation of transport and other osmoregulation pathways, which aligns with the crucial role of these pathways in maintaining biological homeostasis. Notably, we identified candidate genes involved in increased osmoregulatory activity under salinity stress, including those responsible for moving ions across membranes: ion channels, ion pumps, and ion transporters. Particularly, genes from the solute carrier family SLC, aquaporin AQP1, chloride channel CLC7, ATP-binding cassette transporter ABCE1, and ATPases member ATAD2 exhibited prominent differential expression. These findings provide insights into the potential molecular mechanisms underlying the adaptive response of euryhaline fish to salinity stress and have implications for their conservation and management in the face of freshwater salinization.