Project description:Full title: Mercury-Induced Hepatotoxicity in Zebrafish: In Vivo Mechanistic Insights from Transcriptome Analysis, Phenotype Anchoring and Targeted Gene Expression Validation In this study, we performed microarray-based expression profiling on liver of zebrafish exposed to 200 µg/L of mercuric chloride for 8-96 h, to identify global transcriptional programs and biological pathways involved in mercury-induced adaptive responses under in vivo environment.
Project description:To gain more insight into cellular responses to mercury, we have undertaken a large-scale analysis of the rice transcriptome during mercury stress.More transcripts were responsive to mercury during short (pooled from 1- and 3-h treatments) , as compared to long (24 h) exposures. After short exposures, these induced genes can be divided into different functional categories, mainly on the basis of cell wall formation, chemical detoxification, secondary metabolism, signal transduction and abiotic stress response. Molecular mechanisms for the mercury toxicity in rice roots.
Project description:Full title: Mercury-Induced Hepatotoxicity in Zebrafish: In Vivo Mechanistic Insights from Transcriptome Analysis, Phenotype Anchoring and Targeted Gene Expression Validation In this study, we performed microarray-based expression profiling on liver of zebrafish exposed to 200 µg/L of mercuric chloride for 8-96 h, to identify global transcriptional programs and biological pathways involved in mercury-induced adaptive responses under in vivo environment. We analyzed 12 arrays for mercuric chloride treated zebrafish liver and 12 arrays for control liver.
Project description:In this study we tested the ability to predict organ injury from transcriptomics data in Sprague-Dawley rats at early time points after exposure to mercury chloride (10 and 34 hours). We selected mercury chloride, a compound extensively used in animal studies for its ability to cause acute kidney and liver damage.
Project description:To gain more insight into cellular responses to mercury, we have undertaken a large-scale analysis of the rice transcriptome during mercury stress.More transcripts were responsive to mercury during short (pooled from 1- and 3-h treatments) , as compared to long (24 h) exposures. After short exposures, these induced genes can be divided into different functional categories, mainly on the basis of cell wall formation, chemical detoxification, secondary metabolism, signal transduction and abiotic stress response. Molecular mechanisms for the mercury toxicity in rice roots. Two-condition experiment, short exposures and long exposures. Comparison of mock control and rice seedlings treated with 25mM Hg during short (pooled from 1- and 3-h treatments), as compared to long (24 h) exposures.; Biological replicates: 3 control replicates (short and long exposures), 3 Hg-treated replicates (short and long exposures).
Project description:We used comparative transcriptomics to explore cellular responses to growth on pyrite (FeS2) or aqueous iron (Fe(II)) and sulfur (cysteine or sulfide). Transcriptomic data from wild type M. barkeri identified subset of genes that was significantly upregulated during grown on FeS2 versus ferrous iron and cysteine or sulfide. Several of these genes, including a membrane-bound hydrolase, alpha-keto reductases, and flavin mononucleotide-dependent flavodoxin reductases were highly conserved among known FeS2-reducing methanogens and were located in a single gene cassette. Putative enzymatically catalyzed mechanisms of FeS2 reduction are proposed for each of these enzyme systems to guide their future biochemical and biophysical study. Transcriptomic data from wild type M. barkeri identified subset of genes that was significantly upregulated during grown on FeS2 versus ferrous iron and cysteine or sulfide. Several of these genes, including a membrane-bound hydrolase, alpha-keto reductases, and flavin mononucleotide-dependent flavodoxin reductases were highly conserved among known FeS2-reducing methanogens and were located in a single gene cassette. Putative enzymatically catalyzed mechanisms of FeS2 reduction are proposed for each of these enzyme systems to guide their future biochemical and biophysical study.
Project description:The consistent cold temperatures and large amount of precipitation in the Olympic and Cascade ranges of Washington State are thought to increase atmospheric deposition of contaminants in these high elevation locations. Total mercury and 28 organochlorine compounds were measured in composite, whole fish samples collected from 14 remote lakes in the Olympic, Mt. Rainer, and North Cascades National Parks. Mercury was detected in fish from all lakes sampled and ranged in concentration from 17 to 262 ug/kg wet weight. Only two organochlorines, total polychlorinated biphenyls (tPCB) and dichlorodiphenyldichloroethylene (DDE), were detected in fish tissues (concentrations <25 ug/kg wet weight). No organochlorines were detected in sediments (MRL ≈1-5 ug/kg), while median total and methyl mercury in sediments were 30.4 and 0.34 ug/kg (dry weight), respectively. Using a targeted rainbow trout cDNA microarray with known genes, we detected significant differences in liver transcriptional responses, including metabolic, endocrine, and immune-related genes, in fish collected from a contaminated lake compared to a lake with a lower contaminant load. Overall, our results suggest that local urban areas are contributing to the observed contaminant patterns, while the transcriptional changes point to a biological response associated with exposure to these contaminants in fish. Specifically, the gene expression pattern leads us to hypothesize a role for mercury in disrupting the metabolic and reproductive pathways in fish from high elevation lakes in western Washington. Keywords: High altitude lakes, mercury, salmonids, organochlorines
Project description:The effects of mercury (HgCl2) on barley (Hordeum vulgare L.) growth, physiological traits and gene expression profiles were studied. The shoot to root ratio was decreased in the two levels of HgCl2 (500 and 1000 ?M) assayed, which was related primarily with decreases in shoot dry weight. Moreover stomatal conductance was limited and leaf carbon isotope discrimination decreased. Therefore water uptake limitations seem to be an important component of barley responses to HgCl2. Evidences for decreased stomatal conductance and water uptake limitations were further confirmed by the over expression of ABA related transcripts and down regulation of an aquaporin in roots. Root dry weight was only affected at 1000 ?M HgCl2 and root browning was observed, while several transcripts for lignin biosynthesis were up regulated in HgCl2. Microarray analysis further revealed that growth inhibition in HgCl2 was related to increased expression of genes participating in ethylene biosynthesis and down regulation of several genes participating in DNA synthesis, chromatin structure and cell division, cell wall degradation and modification, oxidative pentose phosphate cycle and nitrogen metabolism pathway. Genes involved in detoxification and defence mechanisms were up regulated including several cytochrome P450s, glucosyltransferases and glutathione-s-transferases and amino acid metabolism participatory genes. It is concluded that barley plants survive in the presence of HgCl2 through several mechanisms that include water uptake limitations, shoot and root growth regulation, increased expression of genes involved in the biosynthesis of several plant protection secondary metabolites and finally through detoxification. Six samples were analysed including 3 biological replicates of mercury exposed roots and 3 controls (no mercury added to the growing solution)