Danio rerio
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ABSTRACT:
PROVIDER: PRJNA187042 | ENA |
REPOSITORIES: ENA
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Project description:The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor well known for mediating the toxicity of environmental chemicals such as polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). There is extensive knowledge on the range of target genes regulated by AHR ligands. However, there is limited information on the effect of AHR ligands on DNA methylation. The objective of this study is to investigate genome-wide changes in DNA methylation and gene expression patterns in response to PCB126 exposure. Adult zebrafish were exposed to 10 nM PCB126 for 24 hours (waterborne exposure) and were reared in clean water for 7 days before tissue sampling. DNA methylation and transcriptional changes in the liver and brain tissues were quantified by Reduced Representation Bisulfite Sequencing (RRBS) and RNAseq, respectively. RRBS analysis revealed DNA hypomethylation in response to PCB exposure in both liver and brain tissues. We observed 482 and 476 differentially methylated regions (DMRs) in the liver and brain tissues respectively. Most of the DMRs are located more than 20 kilobases upstream of the transcriptional start sites. RNAseq results from the liver revealed differential expression of genes related to xenobiotic metabolism, oxidative stress and carbohydrate metabolism in response to PCB exposure. In the brain, PCB exposure altered the expression of genes involved in myelination and glutamate signaling. Our results suggest that there is very little correlation between DNA methylation and gene expression patterns among the differentially expressed genes (DEGs). We are currently investigating the relationship between DMRs and DEGs.
2017-09-30 | GSE104221 | GEO
Project description:Several environmental pollutants, especially organic compounds such as polycyclic aromatic hydrocarbons (PAHs) are potent carcinogenic chemicals. Exposure of different fish species to PAHs causes a high prevalence and variety of tumor lesions. To identify and compare the mode of action (MOA) of different model carcinogenic PAHs, a transcriptomic study was carried out in adult zebrafish (Danio rerio) after exposure to 0.3 mg/l of benzo(a)pyrene (B(a)P) or to 7,12-dimethylbenz(a)anthracene (DMBA), both of them dissolved in dimethyl sulfoxide (DMSO; final concentration of 0.01%). Samples for microarray analysis were taken after 1 and 2 weeks of exposure. The changes in the mRNA transcription levels over the corresponding controls were compared among treatments. Correspondence analysis was able to discriminate among treatments; factor 1 separated both sampling times while factor 2 separated the compounds. A total number of 3043 transcripts was shown to be differentially regulated in at least one of the treatments. B(a)P treatment produced regulation of sequences related to GO categories associated to cell cycle and cell division whereas DMBA regulated GO terms related to oxidation/reduction responses, responses to chemicals and response to bacterium. Both compounds were able to alter many xenobiotic metabolism related genes, especially upregulating the transcription of phase I metabolism-related genes such as cytochrome P450 members (cyp1a or cyp1b), and many cancer-related genes such as the Jun B proto-oncogene (junb). Overall, these results indicated that the exposure to both PAHs was able to differentially alter the transcription levels of genes involved in both the detoxification metabolism and the cell-cycle control, including different tumor-supressor genes and oncogens. These alterations have been often related to the appearance of tumor lesions. Zebrafish were waterborne exposed to 0.3ppm BaP or DMBA for 1 and 2 weeks. After 1 and 2 weeks hepatic samples were collected from each treatment group as well as from the control group. 3 biological replicates have been collected per exposure group and time point. Each biological replicate is a pool of 5 livers. Samples from the different treatments were hybridized in an n+2 (n = 9) A-optimal loop design. Additionally, these two designs were linked by two extra hybridizations to enable comparison between time points
2013-10-01 | E-GEOD-43675 | biostudies-arrayexpress
Project description:Waterborne exposure of adult zebrafish to silver nanoparticles and ionic silver results in silver accumulation and effects at cellular and molecular levels
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Project description:Polycyclic Aromatic Hydrocarbons (PAHs) are diverse environmental pollutants associated with adverse human health effects. Many studies focus on the carcinogenic effects of a limited number of PAHs and there is an increasing need to understand mechanisms of developmental toxicity of more varied yet environmentally relevant PAHs. A previous study characterized the developmental toxicity of 123 PAHs in zebrafish. Based on phenotypic responses ranging from complete inactivity to acute mortality, we classified these PAHs into eight bins, selected 16 representative PAHs, and exposed developing zebrafish to the concentration of each PAH that induced 80% phenotypic effect. We conducted RNA sequencing at 48 h post fertilization to identify gene expression changes as a result of PAH exposure.
2020-08-22 | GSE156656 | GEO
Project description:Zebrafish exposed to 2 waterborne copper concentrations (8 & 15 ug/L) in softwater for 21 days. Fish were terminally sampled and livers extracted for RNA extraction and hybridization to micorarrays
2009-09-01 | E-MEXP-2287 | biostudies-arrayexpress
Project description:Development is a complex and well-defined process characterized by rapid cell proliferation and apoptosis. At this stage in life, a developmentally young organism is more sensitive to toxicants and other stressors when compared to an adult. In response to pro-oxidant exposure, members of the Cap’n’Collar (CNC) basic leucine zipper (b-ZIP) transcription factor family (including the Nfe2-related factors, Nrfs) activate the expression of genes that contribute to reduced toxicity. Here, we studied the role of the Nrf protein, Nfe2, in the developmental response to pro-oxidant exposure in the zebrafish. Following acute waterborne exposures to diquat or tert-buytlhydroperoxide (tBOOH) at three developmental stages, wildtype (WT) and nfe2 knockout (KO) embryos and larvae were morphologically scored and their transcriptomes sequenced.
2016-10-10 | GSE83466 | GEO
Project description:Embryonic atrazine exposure elicits neuroendocrine dysfunction in adult male zebrafish (gonad)
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Project description:Embryonic atrazine exposure elicits neuroendocrine dysfunction in adult male zebrafish (brain)
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