Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

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Gene transcription profiling in wild and laboratory-exposed eels reveals common responses to low temperature and chronic pollution exposure

ABSTRACT: Aquatic ecosystems are subjected to a variety of man-induced stressors but also vary spatially and temporally due to variation in natural factors. In such complex environments, it remains difficult for ecotoxicologists to evaluate the effects of contaminants in wild organisms. The aim of the present study was to test the possibility to detect and unravel the effects of different anthropogenic and natural factors on wild fish by the use of a DNA microarray. Transcriptomic profiles from laboratory-exposed and wild fish sampled along a contamination gradient were compared. During laboratory experiments, fish were exposed to pollutants or natural factors under levels that were closed to those found in the sampling sites. A strong difference was observed between the transcriptomic patterns of wild and laboratory-exposed animals, suggesting a general stress induced by captivity in laboratory. Surprisingly, animals acclimatized to cold temperature clustered with fish from the most contaminated sites and shared common genes involved notably in epigenetic mechanisms. A possible energy saving strategy was suggested in cold-acclimated animals. This result may suggest that animals chronically exposed to contaminants develop a general defense/adaptation strategy against pollution through a general shunt in their basal metabolism, whatever the type of contaminants. 84 samples were analyzed from wild and laboratory animals (5 individuals per condition or sampling site). Seven sampling wild sites were selected in Canada (St. Jean, Sud-Ouest, St. FranM-CM-'ois, St. Pierre) and in France (Dordogne, Garonne, Gironde) on the basis of their known gradient of contamination by metallic and organic pollutants previously described in Baillon et al., in press. Each sample were hybridized with a same reference on array (30 samples from reference site (Certes, France) collected in spring 2011 and 2012. Animals from laboratory exposures were described below.

ORGANISM(S): Anguilla anguilla

SUBMITTER: lucie baillon

PROVIDER: E-GEOD-64170 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:A variety of contaminants find their way to the marine sediments from different sources, and these contaminants can pose serious risks to the natural marine flora and fauna. For example, pyrethroids, which are a potent pesticide family, are often used in agriculture fields worldwide, and these find their way into the marine environment through run off. Further, pyrethroids are used in farmed Atlantic salmon cages in Chile, Great Britain and Norway. Ammonia is another contaminant that is used in agriculture in form of ammonia-rich fertilizer and can be carried during run-offs to localized rivers and streams. Ammonia is also detectable after emission of effluents from sewage treatment plants and industrial plants like oil refineries and meat processing plants. Contaminants may have short and long term effects on non-target organisms living in the water column or in the marine sediment. Importantly, the sediment ecosystem houses a variety of plants, animals and crustaceans, including the American lobster Homarus americanus. Lobster is the most fished crustacean in New Brunswick and Quebec and its resale and exportation produced over $1.6 billion in 2011. Due to its economic and environmental importance, it is essential to study the effects of contaminants present in its ecosystem. Sediment samples are often used as pollution markers during toxicity testing due to their tendency to accumulate hydrophobic contaminants. To better understand the possible effects of contaminants in sediment, a total gene expression study was developed using the marine amphipod Eohaustorius estuarius. A 10 day spike-in exposure was performed using ammonia and two pyrethroids, namely cypermethrin and deltamethrin. As pyrethroids and ammonia are known to have vastly different mechanisms of action in living organisms, we compared global gene expression patterns following exposure to ammonia against the patterns observed following exposure to pyrethroids. Total gene expression was measured by oligonucleotide microarray. The expression of five genes of interest involved in different biological processes such as metabolism, transcription, translation, immunity and stress, which were found to be differently expressed by microarray, was validated by RT-qPCR. A set of genes was identified that showed differential expression levels in a treatment-dependent manner, thus further highlighting the different mechanisms of action of ammonia and pyrethroids in the marine sediment. This study provides a proof of concept for the use of DNA microarrays with model crustaceans for the study of marine sediment contaminants. This specific study is aimed at evaluating the effect of ammonia and pyrethroid exposure on E.estuarius and to identify possible biomarkers of these exposures.

Project description:WD40 motif-containing Msi1-like (MSIL) proteins play pleiotropic cellular functions as a negative regulator of the Ras/cAMP-pathways and a component of chromatin assembly factor-I (CAF-I), and yet have not been studied in fungal pathogens. Here we identified and characterized an MSIL protein, Msl1, in Cryptococcus neoformans, which can cause fatal meningoencephalitis in humans. Notably, Msl1 was not a functional ortholog for the yeast Msi1 but played pleiotropic roles in C. neoformans in both cAMP-dependent and -independent manners but mainly Ras-independently. Msl1 negatively controlled antioxidant melanin production and sexual differentiation, which can be repressed by inhibiting the cAMP-signaling pathways. In contrast, Msl1 controlled thermotolerance, diverse stress responses, and antifungal drugs resistance in Ras/cAMP-independent manners. Cac2, which is the second CAF-I component, appeared to play both redundant and distinct function with Msl1. Msl1 is required for full virulence of C. neoformans. Transcriptome and proteomic analysis identified a group of Msl1-regulated genes or -interacting proteins, respectively, which mostly include stress-related genes, including HSP12, HSP78, SSA1, SSA4, and STM1. Furthermore, we identified the third putative component of CAF-1, Rlf2, in C. neoformans. In conclusion, this study demonstrated the pleiotropic roles of Msl1 in human fungal pathogen C. neoformans, providing a novel antifungal therapeutic target. There is more than 95% genome homology between JEC21 and H99. Therefore, 6 slides of JEC21 (Cryptococcus neoformans var. neoformans serotype D) 70-mer oligos are used in this analysis. Total RNAs are extracted from 2 strains from H99 (H99 wild-type strain (Cryptococcus neoformans var. grubii serotype A), msl1M-NM-^T). 3 biological replicate experiments are performed for each strain. We use the mix of all total RNAs from this experiment as the control RNA. We use Cy3 as the test sample dye and Cy5 as the control dye.

Project description:The high osmolarity glycerol response (HOG) pathway plays a pivotal role in the stress response, virulence regulation, and differentiation of fungi, including Cryptococcus neoformans that causes fatal meningoencephalitis. Core signaling components of in the HOG pathway, including the Tco-Ypd1-Ssk1 phosphorelay system and the Ssk2-Pbs2-Hog1 MAPK module, have been elucidated but its downstream transcription factors remain unclear. Here we demonstrated that Atf1 with a basic leucine zipper domain is the transcription factor downstream of Hog1 in C. neoformans. We found that ATF1 expression was differentially regulated by oxidative damaging agents, mainly in a Hog1-dependent, but Mpk1-independent, manner. Interestingly, Atf1 not only promoted oxidative stress response and adaptation, but also played an opposing role to Hog1 in the process. Atf1 primarily localized to the nucleus under both unstressed and oxidative stress conditions in a Hog1-independent manner. Our data demonstrated that Atf1 promoted pheromone production and sexual differentiation under negative control by Hog1. Finally, a DNA microarray-based transcriptome analysis of the atf1M-bM-^HM-^F mutant under unstressed and oxidative stress conditions revealed that Atf1 regulated oxidative stress response genes, including a sulfiredoxin gene (SRX1). Intriguing, the array data further demonstrated that Atf1 modulated basal expression of genes involved in DNA repair and genotoxic stress response. Supporting this, we found that the atf1M-bM-^HM-^F mutant was highly sensitive to genotoxic agents. In conclusion, this study provided a further insight into the Hog1-dependent oxidative and genotoxic stress response and differentiation mechanism of C. neoformans. There are more than 95% of genome homology between JEC21 and H99. Therefore 6 slides of JEC21 (Cryptococcus neoformans var. neoformans serotype D) 70-mer oligo are used in this analysis, 3 biological replicate experiments are performed, total RNAs are extracted 2 conditions (with or without treatment of Hydroten peroxide) from H99 (H99 Wild type strain (Cryptococcus neoformans var. grubii serotype A), and atf1M-NM-^T). We use the mixed all of total RNAs from this experiment as a control RNA. We use Cy3 as Sample dye and Cy5 as a control dye.

Project description:Carbon dioxide (CO2) sensing, transport, and metabolism play a pivotal role in survival and proliferation of pathogenic microbes infecting human host from natural environments due to the drastic difference of CO2 levels. Carbonic anhydrases (CAs) are not only key CO2-metabolic enzymes catalyzing reversible interconversion between CO2 and bicarbonate (HCO3-), but also important CO2-signaling modulators. Cryptococcus neoformans that causes fatal fungal meningitis contains two functional CAs, Can1 and Can2, among which Can2 plays essential roles for growth and sexual differentiation of the pathogen. However, downstream genes and signaling network regulated by CAs have not been studied thus far. In this study, we constructed a C. neoformans strain where CAN2 expression is controlled by the CTR4 (copper transporter) promoter and elucidated its transcriptome patterns by using DNA microarray analysis to elucidate downstream target genes of Can2. Expectedly, the CAN2 promoter replacement strain showed growth defects in a CO2-dependent manner when CAN2 is repressed. The CA-transcriptome analysis discovered a number of Can2-dependent genes, including those involved in fatty acid biosynthesis (FAS1), sexual differentiation (GPB1), capsule structure organization (CAS3), iron-metabolism (CFO2), and a number of stress-regulated genes, including an oxidative stress-responsive Atf1 transcription factor, although a majority of them do not have any orthologs in other fungi. The present study revealed other roles of Atf1 in capsule and melanin production and diverse stress responses, including thermotolerance and antifungal drug resistance, of C. neoformans. This study provides further insights into the signaling network of CA/CO2-sensing pathway in pathogenic fungi. 17 slides are used in this analysis, 3 or 2 biological replicate experiments are performed, total RNAs are extracted from 2 strains (H99 Wild type strain, CTR4::CAN2) at 2 time points (0hr time, 12hr time) in 2 conditions (BCS, CuSO4). We use the mixed all of total RNAs from this experiment as a control RNA. We use Cy5 as Sample dye and Cy3 as a control dye. Several experiment samples are dye swaped.

Project description:BACKGROUND: Lithospermum erythrorhizon, popularly known as Gromwell, is a perennial herb belonging to the family of Boraginaceae and its extract is known to have diverse pharmacological, cosmetic, and nutritional values for human. Nevertheless the biological influence of Gromwell extract on general physiology of eukaryotic cells remains unknown. In this study, we for the first time performed a global transcriptome analysis by using DNA microarray analysis to identify genes affected by the addition of Gromwell extract (GE) by using a eukaryotic microorganism, basidiomycete fungus Cryptococcus neoformans, as a model system. RESULTS: The transcriptome analysis revealed that a total of 1932 genes are differentially regulated in a statistically significant manner and expressions of 715 genes are up- (315 genes) or down-regulated (457 genes) more than twofold upon GE treatment. In response to GE treatment, genes involved in signal transduction genes are immediately regulated and the evolutionarily conserved set of genes involved in the core cellular functions, including DNA replication, RNA transcription/processing, and protein translation/processing, are generally upregulated. In contrast, a number of genes involved in carbohydrate metabolism and transport, inorganic ion transport and metabolism, post-translational modification/protein turnover/chaperone functions, and signal transduction are downregulated by the GE treatment. Among the GE-responsive genes that are also evolutionarily conserved in the human genome, we confirmed expression patterns of YSA1, TPO2, FET5 (CFO1), and PZF1 by Northern blot analysis. Based on the functional characterization of some GE-responsive genes through phenotypic analysis of gene knockout mutants, we found that GE treatment may promote cellular tolerance against a variety of environmental stresses in eukaryotes. CONCLUSIONS: A significant portion of the Cryptococcus genome is affected in expression levels by treatment of GE, implying that the general physiology of eukaryotic cells is significantly affected by the GE treatment. There are more than 95% of genome homology between JEC21 and H99. Therefore 6 slides of JEC21 (Cryptococcus neoformans var. neoformans serotype D) 70-mer oligo are used in this analysis, 3 biological replicate experiments are performed, total RNAs are extracted from H99 (H99 Wild type strain (Cryptococcus neoformans var. grubii serotype A)) with 6.4 mg/ml Gromwell extract in 0, 10, 30, 60 min. We use the mixed all of total RNAs from this experiment as a control RNA. We use Cy3 as Sample dye and Cy5 as a control dye.

Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions We were interested to study the global reactions of bacteria with biodegradative properties under near-environmental as compared to laboratory culture conditions. we compared here the genome-wide responses of RW1 between regular laboratory batch growth on the aromatic substrates DBF and salicylate with growth in sandy soil with or without the same aromatic compounds. We analysed the cellular reactions immediately after introduction into the sand, during lag phase, all in carefully controlled and replicated experimental conditions.

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Gene transcription profiling in wild and laboratory-exposed eels reveals common responses to low temperature and chronic pollution exposure

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