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.
2024-03-14 | GSE254383 | GEO
Project description:Experimental salinization of historically freshwater bacterial communities
| PRJNA615001 | ENA
Project description:Appalachian stream leaf litter microbiota under salinization
| PRJNA484970 | ENA
Project description:Subsidy-stress response of bacterial respiration and nutrient uptake rates to freshwater salinization
Project description:Because antibiotics have been widely used to prevent severe losses due to infectious fishery diseases, the liberal application and overuse of antibiotics has led to the spread and evolution of bacterial resistance, food safety hazards, and environmental issues. The use of some antibiotics, including florfenicol and enrofloxacin, is allowed in aquaculture in China. Accordingly, to better address the concerns and questions associated with the impact of administered enrofloxacin and florfenicol to grass carp, here we investigated the immune response, bacterial diversity, and transcriptome of the intestine of C. idella treated with these oral antibiotics. The aim of this study was to provide an in-depth evaluation of the antibiotic-induced patterns and dynamics of the microbiota grass carp and the potential mechanism involved.
Project description:The hormonal contraceptive medroxyprogesterone acetate (MPA) is associated with increased risk of human immunodeficiency virus (HIV), via incompletely understood mechanisms. Increased diversity in the vaginal microbiota modulates genital inflammation and is associated with increased HIV-1 acquisition. However, the effect of MPA on diversity of the vaginal microbiota is relatively unknown. In a cohort of female Kenyan sex workers, negative for sexually transmitted infections (STIs), with Nugent scores <7 (N=58 of 370 screened), MPA correlated with significantly increased diversity of the vaginal microbiota as assessed by 16S rRNA gene sequencing. MPA was also significantly associated with decreased levels of estrogen in the plasma, and low vaginal glycogen and α-amylase, factors implicated in vaginal colonization by lactobacilli, bacteria that are believed to protect against STIs. In a humanized mouse model, MPA treatment was associated with low serum estrogen, low glycogen and enhanced HIV-1 susceptibility. The mechanism by which the MPA mediated changes in the vaginal microbiota may contribute to HIV-1 susceptibility in humans appears to be independent of inflammatory cytokines and/or activated T cells. Altogether, these results suggest MPA-induced hypo-estrogenism may alter key metabolic components that are necessary for vaginal colonization by certain bacterial species including lactobacilli, and allow for greater bacterial diversity in the vaginal microbiota.
Project description:Global climate change increasingly polarizes environments, presenting unprecedented challenges to many organisms (Smol, 2012). Polarization occurs not only in the spatial dimension, producing greater desert drought and tropical rainfall, for example, but also in the temporal dimension by making a local environment more variable over time. Many organisms survive these fluctuating environmental conditions by manifesting multiple distinct phenotypes through developmental processes that enable phenotypic plasticity (Pigliucci et al., 2006; Parsons et al., 2011). As with early development, these processes are expected to strictly regulate gene expression to canalize phenotype, despite the genetic diversity within populations (Alberch, 1982; Riska, 1986, Pigliucci et al., 1996). For plasticity to evolve, natural selection must act on genes that regulate trait variation, e.g, those conferring norms of reaction to a specific set of conditions. Despite the importance of these reaction norms for coping with environmental challenges, the genetic framework underlying phenotypic plasticity remains poorly defined, making it impossible to study how they function, differ among natural populations, and evolve. Here we used arsenic, a chemical inhibitor of salinity acclimation, to identify genes involved in transforming the gill from its freshwater to its seawater architecture in the euryhaline teleost Fundulus heteroclitus. Linear model interaction terms associated with the combined effect of arsenic and salinity challenge revealed an antagonistic relationship between arsenic exposure and salinity acclimation Exposure to arsenic during salinity acclimation yielded gene expression values similar to those observed in unexposed fish that remained in a stable environment, demonstrating that arsenic prevents changes in gene expression that normally enable osmotic plasticity. The gene sets defined by the interaction terms showed reduced inter-individual variation, suggesting unusually tight control, consistent with the hypothesis that they participate in a canalized developmental response. Evidence that natural selection acts to preserve their canalized gene expression was obtained by referencing three populations that differ in their adaptive tolerance to salinity changes (Whitehead et al., 2011). Specifically, populations adapted to withstand the widest salinity range showed both reduced transcriptional variation in genes enabling gill plasticity and an increased osmoregulatory capacity, highlighted by more stable plasma chloride concentrations in response to an osmotic challenge. Finally, we observed significantly fewer associations between genes underlying trait variation and their transcriptional regulators compared to genes that responded to only arsenic or salinity. Collectively, our results demonstrate that phenotypic plasticity converges on a molecular solution that parallels early development, in which the expression of phenotypic plasticity genes and phenotypes are canalized in part by reducing trans-regulatory complexity. 36 Sample comparisons with fish gills exposed to freshwater, freshwater to seawater for 1 hour, freshwater to seawater for 1 hour with arsenic, freshwater to seawater for 24 hours, freshwater to seawater for 24 hours with arsenic, and freshwater with arsenic for 48 hours