Transcriptomic underpinning of toxicant-mediated physiological functionalterations in three terrestrial invertebrate taxa: A review. EnvironmentalPollution. 158 (2010) 2793-2808. Impact factor 2010: 3.4 (original) (raw)
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Ecotoxicology, 2000
Bioaccumulation and toxicity tests using benthic invertebrates such as the estuarine amphipod Leptocheirus plumulosus are typically used to assess the ecological risk associated with contaminated sediments. Despite their ecological and regulatory importance, little is known about such species at the genetic level. To begin understanding cellular and genetic responses of L. plumulosus to contaminants, we isolated several of their genes and developed quantitative assays to measure the effects of water exposures to 2, 4, 6-trinitrotoluene and phenanthrene on gene expression. Real-time polymerase chain reaction (PCR) assays demonstrated that the expression of the genes for actin and a retrotransposon, hopper, was dependent on the exposure and tissue concentrations of those chemicals. Our data suggests that exposure to the explosive 2, 4, 6-trinitrotoluene and phenanthrene may induce movement of hopper resulting in unexpected genotoxic results.
Ecotoxicology (London, England), 2012
The soil oligochaete Enchytraeus albidus is a standard test organism used in biological testing for Environmental Risk Assessment (ERA). Although effects are known at acute and chronic level through survival, reproduction and avoidance behaviour endpoints, very little is known at the sub-cellular and molecular levels. In this study, the effects of soil properties (clay, organic matter and pH) and of the chemicals copper and phenmedipham were studied on E. albidus gene expression, during exposure periods of 2, 4 and 21 days, using DNA microarrays based on a normalised cDNA library for this test species (Amorim et al. 2011). The main objectives of this study were: (1) to assess changes in gene expression of E. albidus over time, and (2) to identify molecular markers for natural and chemical exposures. Results showed an influence of exposure time on gene expression. Transcriptional responses to phenmedipham were seen at 2 days while the responses to copper and the different soils were more pronounced at 4 days of exposure. Some genes were differentially expressed in a stress specific manner and, in general, the responses were related with effects in the energy metabolism and cell growth.
Critical Analysis of Soil Invertebrate Biomarkers: A Field Case Study in Avonmouth, UK
Ecotoxicology, 2004
During the period 1996-1999 a joint field research programme (BIOPRINT-II) funded by the European Union was undertaken. The main objective of this project was the deployment of biochemical fingerprint techniques of soil invertebrate biomarkers for assessing the exposure and effect of toxicants on soil invertebrates in the field. The aim was to apply these techniques in the field focusing on a a chronically polluted field near a lead and zinc smelter in Avonmouth (UK). Therefore six sites were selected from which organisms were either sampled or transplanted to or from the laboratory. The project has provided a unique opportunity to apply a series of biological test methodologies in order to determine the hazard posed to soil sustainability and by inference soil biodiversity and function. This work has attempted to understand the linkage between effects measured at the molecular or cellular level and relate these to changes at higher levels of biological organisation. Here we evaluated the links between biomarkers and soil function parameters. The paper aims to summarize and explore the necessary caveats that must be understood before soil biomarker test systems may be used to strengthen the risk assessment process.
Transcriptome profiling in crustaceans as a tool for ecotoxicogenomics
Cell Biology and Toxicology, 2008
Chemicals released into the environment have the potential to affect various species and it is important to evaluate such chemical effect on ecosystems, including aquatic organisms. Among aquatic organisms, Daphnia magna has been used extensively for acute toxicity or reproductive toxicity tests. Although these types of tests can provide information on hazardous concentrations of chemicals, they provide no information on their mode of action. Recent advances in toxicogenomics, the integration of genomics with toxicology, have the potential to afford a better understanding of the responses of aquatic organisms to pollutants. In a previous study, we developed an oligonucleotide-based DNA microarray with high reproducibility using a Daphnia expressed sequence tag (EST) database. In this study, we increased the number of genes on the array and used it for a careful ecotoxicogenomic assessment of Daphnia magna. The DNA microarray was used to evaluate gene expression profiles of neonate daphnids exposed to beta-naphthoflavone (bNF). Exposure to this chemical resulted in a characteristic gene expression pattern. As the number of the genes on an array was increased, the number of genes that were found to respond to the chemicals was also increased, which made the classification of the toxic chemicals easier and more accurate. This newly developed DNA microarray can be useful for a obtaining a better mechanistic understanding of chemical toxicity effects on a common freshwater organism.
Gene Expression Analysis Reveals a Gene Set Discriminatory to Different Metals in Soil
Toxicological Sciences, 2010
Polycyclic aromatic hydrocarbons are common pollutants in soil, have negative effects on soil ecosystems, and are potentially carcinogenic. The springtail (Collembola) Folsomia candida is often used as an indicator species for soil toxicity. Here we report a toxicogenomic study that translates the ecological effects of the polycyclic aromatic hydrocarbon phenanthrene in soil to the early transcriptomic responses in Folsomia candida.
Invertebrate stress responses as molecular biomarkers in ecotoxicology
All organisms studied so far respond to heat shock by inducing the synthesis of a number of proteins called heat shock proteins(LISPs). This universal response can also be induced by a variety of stressors, including heavy metal ions and organic and organo-metallic compounds. As a result, the stress response has recently attracted the attention of ecotoxicologists for use in environmental biomonitoring. In the present study, we have investigated the stress responses of two different organisms ; namely the free-living soil nematode Caenorhiabdities elegans(both wild-type and transgenic strains) and the freshwater crustacea Asellus aquazicus. We have also explored the possible use of these model systems in environmental monitoring using different techniques which include metabolic labelling with subsequent one-dimensional electrophoresis and autoradiography, and one- or two-dimensional western blotting using antibodies specific to stress protein 70. The study with A. aquaticus shows t...
Background: The soil worm Enchytraeus crypticus (Oligochaeta) is an ecotoxicology model species that, until now, was without genome or transcriptome sequence information. The present research aims at studying the transcriptome of Enchytraeus crypticus, sampled from multiple test conditions, and the construction of a high-density microarray for functional genomic studies. Results: Over 1.5 million cDNA sequence reads were obtained representing 645 million nucleotides. After assembly, 27,296 contigs and 87,686 singletons were obtained, from which 44% and 25% are annotated as protein-coding genes, respectively, sharing homology with other animal proteomes. Concerning assembly quality, 84% of the contig sequences contain an open reading frame with a start codon while E. crypticus homologs were identified for 92% of the core eukaryotic genes. Moreover, 65% and 77% of the singletons and contigs without known homologs, respectively, were shown to be transcribed in an independent microarray experiment. An Agilent 180 K microarray platform was designed and validated by hybridizing cDNA from 4 day zinc-exposed E. crypticus to the concentration corresponding to 50% reduction in reproduction after three weeks (EC50). Overall, 70% of all probes signaled expression above background levels (mean signal + 1x standard deviation). More specifically, the probes derived from contigs showed a wider range of average intensities when compared to probes derived from singletons. In total, 522 significantly differentially regulated transcripts were identified upon zinc exposure. Several significantly regulated genes exerted predicted functions (e.g. zinc efflux, zinc transport) associated with zinc stress. Unexpectedly, the microarray data suggest that zinc exposure alters retro transposon activity in the E. crypticus genome.