Gene expression alteration associated with early embryonic MeHg exposure in zebrafish (Danio rerio)
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ABSTRACT:
ORGANISM(S): Danio rerio
PROVIDER: GSE74416 | GEO | 2018/01/01
SECONDARY ACCESSION(S): PRJNA300316
REPOSITORIES: GEO
Similar Datasets
Project description:Gene respons in the central nervous system of zebrafish embryos exposed to the neurotoxicant methyl mercury Two-condition experiment, control vs MeHg exposure embryos (60 µg/l), Biological replicates: 4, dye swaps
2012-05-14 | E-GEOD-37970 | biostudies-arrayexpress
Project description:Methylmercury (MeHg) is a ubiquitous environmental neurotoxicant, with human exposures predominantly resulting from fish consumption. Developmental exposure of zebrafish to MeHg is known to alter their neurobehavior. The current study investigated the direct exposure and transgenerational effects of MeHg, at tissue doses similar to those detected in exposed human populations, on sperm epimutations (i.e., differential DNA methylation regions [DMRs]) and neurobehavior (i.e., visual startle and spontaneous locomotion) in zebrafish, an established human health model. F1 generation embryos were exposed to MeHg (0, 1, 3, 10, 30, and 100 nM) for 24 hours ex vivo. F1 generation control and MeHg-exposed lineages were reared to adults and bred to yield the F2 generation, which was subsequently bred to the F3 generation. Direct exposure (F1 generation) and transgenerational actions (F3 generation) were then evaluated. Hyperactivity and visual deficit were observed in the unexposed descendants (F3 generation) of the MeHg-exposed lineage compared to control. An increase in F3 generation sperm epimutations was observed relative to the F1 generation. Investigation of the DMRs in the F3 generation MeHg-exposed lineage sperm revealed associated genes in the neuroactive ligand-receptor interaction and actin-cytoskeleton pathways being effected, which correlate to the observed neurobehavioral phenotypes. Developmental MeHg-induced epigenetic transgenerational inheritance of abnormal neurobehavior is correlated with sperm epimutations in F3 generation adult zebrafish. Therefore, mercury has the ability to promote the epigenetic transgenerational inheritance of disease in zebrafish, which significantly impacts its environmental health considerations in all species including humans.
2017-01-24 | GSE89144 | GEO
Project description:Methylmercury is a bioaccumulated environmental neurotoxicant, however, it remains largely unknown regarding impacts of non-apoptotic low dose methylmercury on embryonic cerebral cortex development. Here, using single cell RNA-seq analysis we show that prenatal exposure of MeHg favors RGP developmental trajectory towards directly producing cortical neurons, omitting intermediate progenitor stage. Our findings reveal the outcomes of low dose MeHg exposure on the fetal brain development and provide insights into its underlying mechanisms and potential therapeutic strategy.
2023-02-13 | GSE178929 | GEO
Project description:Methylmercury (MeHg) toxicity in humans manifests deficits in neurological function. Cases of prenatal exposure to mercury have established that the developing nervous system is most highly susceptible to perturbation by MeHg. At a cellular level, MeHg-induced defects result from altered neuronal proliferation, migration and pathfinding. However, the molecular targets of MeHg that give rise to these outcomes are not fully understood. In an overall effort to identify the fundamental molecular targets of MeHg in neural development, we are investigating the effects of MeHg on gene expression and protein function in the Drosophila model. Since the fundamental signaling pathways in development of multicellular animals have been extensively characterized in Drosophila, and demonstrate high degree of conservation in vertebrates, we believe these data will lead us to the most pertinent pathways affected by MeHg and begin to elucidate the mechanism of MeHg neural toxicity relevant to cases of human exposure to this prevalent environmental toxin. Our aim is to identify fundamental signaling pathways in neural development that are targets for MeHg poisoning. Our hypothesis is that MeHg, by direct interaction with cysteine thiol groups, alters the function signaling pathway proteins and subsequently alters transcription of target genes in the respective pathways. Our hypothesis is supported by our recent data demonstrating a direct action of MeHg in activating the Notch receptor pathway and upregulating target gene expression. We anticipate a microarray analysis will elucidate additional fundamental signaling pathways where transcription is affected by this toxin. Fertilized female flies are fed on food containing methylmercury (1-20 micromolar) or solvent control (DMSO) for a period of five days to allow for MeHg penetration in to eggs. Flies are then transfered to a cage for embryo collection for a discrete window of time (e.g. 1hr). Embryos are aged 16-24 hours and collected for total RNA extraction using the Trizol reagent. Total RNA is quantitated by spectrophotometry with a Nanodrop reader. While concentration dependent effects of MeHg are of interest, initial experiments will be conducted on samples exposed to a single concetration known to illicit effect in other bioassays (e.g. 10 micromolar). The goal is to see which genes are up- or down-regulated with MeHg exposure, as compared to control embryos that are not exposed. Emphasis in the analysis stage will be in identifying target genes of known signaling pathways.
2008-03-13 | E-GEOD-9271 | biostudies-arrayexpress
Project description:This study sought to evaluate the effects of dietary MeHg exposure on adult female yellow perch (Perca flavescens) and zebrafish (Danio rerio) reproduction by relating controlled exposures with subsequent reproductive effects. Yellow perch were used in the study for their socioeconomic and ecological importance within the Great Lakes basin, and the use of zebrafish allowed for a detailed analysis of the molecular effects of MeHg. MeHg exposures at environmentally relevant levels were done in zebrafish for a full life cycle, mimicking a realistic exposure scenario, and in adult yellow perch for twenty weeks, capturing early seasonal ovarian development. In zebrafish, several genes involved in reproductive processes were shown to be dysregulated by RNA-seq and QPCR, but no significant phenotypic or physiological changes were observed with ovarian staging, fecundity, or embryo mortality. Yellow perch did not appear to be affected by MeHg, either at a molecular level, as assessed by QPCR of eight genes in the pituitary, liver, and ovary tissue, or a physiological level, as seen with ovarian somatic index, circulating estradiol, and ovarian staging. Lack of impact in yellow perch limits the usefulness of zebrafish as a model and suggests that the reproductive sensitivity to environmentally relevant levels of MeHg differs between yellow perch and zebrafish.
2018-01-01 | GSE73615 | GEO
Project description:Methylmercury (MeHg) is an environmental pollutant of global public health concern. MeHg is associated with immune dysfunction but the underlying mechanisms are unclear. The most common route of MeHg exposure is through consumption of fatty fish that contain beneficial n-3 polyunsaturated fatty acids (PUFA) that may protect against MeHg toxicity. To better inform individual costs and benefits of fish consumption, we aimed to identify candidate epigenetic biomarkers of biological responses that reflect MeHg toxicity and PUFA protection.
2022-10-06 | GSE207443 | GEO
Project description:This study aims at investigating the effects of methylmercury on a microalga using a transcriptomic approach. Algal cells were exposed two hours in a simplified artificial medium spiked with 0.05 or 0.5 nM MeHg. Total RNA was extracted using TRI Reagent®. Libraries were prepared with the Illumina TruSeq Stranded mRNA kit and sequenced on an Illumina HiSeq 2500 System.
2016-06-20 | GSE70066 | GEO
Project description:In this dose series pregnant CD-1 (outbred) dams were exposed to methylmercury (MeHg) as monomethylmercuric chloride injected intraperitoneally on 9 d.p.c. Test doses were 10.0 mg/kg and below. This regimen induces symptoms of Fetal Minimata Disease (FMD) in term fetuses. Risks with respect to FMD for the various test doses were 10.0 mg/kg (40% risk), 5.0 mg/kg (20% risk), 2.5 mg/kg (NOAEL), and 1.25 mg/kg (subNOAEL). All measurements were on RNA from the embryonic forebrain (prosencephalon and surrounding tissue) at 3.0h post-treatment. Keywords = dose series Keywords = mercury Keywords = embryo Keywords = Fetal Minamata Disease Keywords: dose response
2004-03-11 | GSE1075 | GEO
Project description:Three-month old zebrafish were fed Biodiet starter (4% body weight per day) with MeHg added at 0, 0.5, 5 and 50 ppm for six weeks. Atomic absorption spectrometry was applied to measure the level of MeHg in the whole fish body. Zebrafish at six weeks were sampled from each group for gene expression analysis by NimbleGen Gene Expression 12X135K zebrafish microarrays. MeHg-exposed trout and zebrafish did not show overt signs of toxicity, nor were significant differences seen in mortality, length, mass, or condition factor. The chronic accumulation of total Hg in zebrafish exhibited dose- and time-dependent patterns. The dysregulated genes in MeHg-treated fish have multiple functional annotations, such as involving metabolism, cellular development, ion binding, stress response, transcriptional regulation, and apoptotic pathways. These results show that numerous molecular pathways involved in the growth and development of multiple organ systems are disrupted by exposure to moderate levels of dietary MeHg. The dysregulated genes will be selected by further analysis and used as biomarkers for MeHg exposure in aquatic environments. This study will allow us to assess the potential impacts of low-level exposure to environmental MeHg in the food chain and on the health of humans and animals. Three-month old zebrafish (Danio rerio, average body 0.149 g) were fed Biodiet Starter (Bio-Oregon) 4% of body weight per day with MeHg added at 0ppm, 0.5ppm, 5ppm and 50ppm (with ethanol as vehicle). Fish at six weeks were sampled from each group for gene expression analysis. Three fish from each treatment group were used for microarray experiments. Total RNA from individual fish was isolated using Trizol reagent (Invitrogen) and further purified using the RNeasy MiniElute cleanup kit (Qiagen). Double-strand cDNA was synthesized from 10ug total RNA of individual fish by using Superscript Double-Stranded cDNA synthesis Kit (Invitrogen). ). One ug double strand DNA was labeled with Cy3 using One-Color DNA labeling Kit (NimbleGen), then hybridized to NimbleGen 12X135K array. The arrays were scanned at 2um on a NimbleGen MS200 scanner with auto-gain adjust. The TIFF images were gridded and extracted using NimbleScan v. 2.6. Expression data were normalized using the Robust Multichip Average (RMA) algorithm.
2013-06-01 | E-GEOD-32430 | biostudies-arrayexpress
Project description:Gene respons in the central nervous system of zebrafish embryos exposed to the neurotoxicant methyl mercury
2012-05-15 | GSE37970 | GEO