Project description:Increasing concern about pollution of our environment calls for advanced and rapid methods to estimate ecological toxicity. The use of gene expression microarrays in environmental studies can potentially meet this challenge. We present a novel method to examine soil toxicity. We exposed the collembolan Folsomia candida to soil containing an ecologically relevant cadmium concentration, and found a cumulative total of 1586 differentially expressed transcripts across three exposure durations, including transcripts involved in stress response, detoxification, and hypoxia. Additional enrichment analysis of gene ontology (GO) terms revealed that antibiotic biosynthesis is important at all time points examined. Interestingly, genes involved in the "penicillin and cephalosporin biosynthesis pathway" have never been identified in animals before, but are expressed in F. candida’s tissue. The synthesis of antibiotics can possibly be a response to increased cadmium-induced susceptibility to invading pathogens, which might be caused by repression of genes involved in the immune-system (C-type lectins and Toll receptor). This study presents a first global view on the environmental stress response of an arthropod species exposed to contaminated soil,and provides a mechanistic basis for the development of a gene expression soil quality test. Keywords: cadmium, soil, Collembola, environmental genomics
Project description:Purpose: Cadmium is a nonessential heavy metal and a well known toxic agent. Cadmium is known to alter the gene expression and signaling but the role of miRNAs during Cadmium exposure is not understood. Methods: Mice were treated with 100 mg/ ml cadmium chloride for 120 days and accumulation of cadmium in blood and organs are confirmed by GFAAS. Subsequently, the total RNA was isolated from the whole blood and small RNA sequencing was executed in Illumina HiSeq 1000. Results: The reads were annotated to the mice genome and miRNAs in miRbase using miRDeep* and novel miRNAs were also predicted. The differential expression was studied by DeSeq Conclusions: This is the first report to reveal the cadmium responsive miRNome. These candidate miRNAs can serve as biomarkers for cadmium
Project description:Purpose: Cadmium is a nonessential heavy metal and a well known toxic agent. Cadmium is known to alter the gene expression and signaling but the role of miRNAs during Cadmium exposure is not understood. Methods: Mice were treated with 100 mg/ ml cadmium chloride for 120 days and accumulation of cadmium in blood and organs are confirmed by GFAAS. Subsequently, the total RNA was isolated from the whole blood and small RNA sequencing was executed in Illumina HiSeq 1000. Results: The reads were annotated to the mice genome and miRNAs in miRbase using miRDeep* and novel miRNAs were also predicted. The differential expression was studied by DeSeq Conclusions: This is the first report to reveal the cadmium responsive miRNome. These candidate miRNAs can serve as biomarkers for cadmium Whole blood small RNA profiles of control and cadmium exposed mice generated by deep sequencing using Illumina HiSeq 1000
Project description:Verbena bonariensis is a species with excellent garden plant, good environmental adaptability and great potential for future development.Cadmium has caused serious heavy metal pollution in the soil, which has posed a great threat to plant growth. In this study, Illumina sequencing technology was used to sequence the transcriptome of Verbena bonariensis leaf under normal and Cd stress, respectively. In total, 95,013 transcripts and 63021 genes with an average length of 923 bp and 1,246 bp were constructed from the clean sequence reads, respectively. And 1037 DEGs were found in response to cadmium treatment, of which 10 were selected for qRT-PCR. In conclusion, this study first identified the Verbena bonariensis as a heavy metal tolerant plant and provided the first large-scale transcriptional data set in response to cadmium stress. Our research will help to understand the mechanism of resistance to Cd in the Verbena bonariensis and provide clues for further studies on the relationships between plants and heavy metals in other Verbenaceae plants.
Project description:Ecotoxicological tests may be biased by the use of laboratory strains that usually contain very limited genetic diversity. It is therefore essential to study how genetic variation influences stress tolerance relevant for toxicity outcomes. To that end we studied sensitivity to cadmium in two distinct genotypes of the parthogenetic soil ecotoxicological model organism Folsomia candida. Clonal lines of both genotypes (TO1 and TO2) showed divergent fitness responses to cadmium exposure; TO2 reproduction was 20% less affected by cadmium. Statistical analyses revealed significant differences between the cadmium-affected transcriptomes; i) the number of genes affected by cadmium in TO2 was only minor (~22%) compared to TO1; ii) 97 genes showed a genotype M-CM-^W cadmium interaction and their response to cadmium showed globally larger fold changes in TO1 when compared to TO2; iii) the interaction genes showed a concerted manner of expression in TO1 while a less coordinated pattern was observed in TO2. We conclude that (1) there is genetic variation in parthenogenetic populations of F. candida, and (2) this variation affects life-history and molecular endpoints relative to cadmium toxicity. This sheds new light on the sources of biological variability in test results, even when the test organisms are thought to be genetically homogeneous because of their parthenogenetic reproduction. Gene expression was measured in two different clones (TO1 and TO2) of the springtail Folsomia candida, after exposure of 2 days to soil containing cadmium (Cd+) and non-spiked (Cd-) soil. A 2 x 2 factorial analysis was performed, to examine the effect of clone (TO1, TO2), of treatment (Cd+, Cd-), and the clone x treatment interaction.
Project description:rs06-03_cd-mirna - cadmium-mirna - trancriptional and post-transcriptional response to cadmium. - After 5 days of grown in a fresh medium (5% PCV at day0), CdCl2 was added to tested cells (Cad) to a final concentration of 200uM. Nothing was added to control cells (Tem). After 12 and 24 hours of growth +/- cadmium, cells were harvested and frozen in liquid nitrogen.
Project description:Field-selected tolerance to heavy metals has been reported for Orchesella cincta (Arthropoda: Collembola) populations occurring at metal-contaminated mining sites. This tolerance is correlated with heritable increase of metal excretion efficiency; less pronounce cadmium induced growth reduction and, over-expression of the metallothionein gene. We applied transcriptomics to determine differential gene expression caused by this abiotic stress in reference and cadmium tolerant populations. Many cDNAs responded to cadmium exposure in a reference population. Significantly fewer clones were cadmium responsive in tolerant animals. Analysis of variance revealed transcripts that interact between cadmium exposure and population. Hierarchical clustering of these clones revealed two major groups. The first one contained cDNAs that were up regulated by cadmium in the reference culture, but non-responsive or down regulated in tolerant animals. This cluster was also characterized by elevated constitutive expression in the tolerant population. Gene ontology analysis revealed that these cDNAs were involved in structural integrity of the cuticle, anti-microbial defense, calcium-channel blocking, neurotransmitter transport, chromatin remodeling and, endoplasmatic vesicle activity. The second group consisted of cDNAs down regulated in reference animals but not responding or slightly up regulated in tolerant animals. Their functions involved carbohydrate metabolic processes, Ca2+ dependent stress signaling, proteolysis and digestion. The reference population showed a strong signature of stress-induced genome-wide perturbation of gene expression, whereas the tolerant animals maintained normal gene expression upon cadmium exposure. We confirmed the micro-evolutionary processes occurring in soil arthropod populations and suggest a major contribution of gene regulation to the evolution of a stress-adapted phenotype.
Project description:Ecotoxicological tests may be biased by the use of laboratory strains that usually contain very limited genetic diversity. It is therefore essential to study how genetic variation influences stress tolerance relevant for toxicity outcomes. To that end we studied sensitivity to cadmium in two distinct genotypes of the parthogenetic soil ecotoxicological model organism Folsomia candida. Clonal lines of both genotypes (TO1 and TO2) showed divergent fitness responses to cadmium exposure; TO2 reproduction was 20% less affected by cadmium. Statistical analyses revealed significant differences between the cadmium-affected transcriptomes; i) the number of genes affected by cadmium in TO2 was only minor (~22%) compared to TO1; ii) 97 genes showed a genotype × cadmium interaction and their response to cadmium showed globally larger fold changes in TO1 when compared to TO2; iii) the interaction genes showed a concerted manner of expression in TO1 while a less coordinated pattern was observed in TO2. We conclude that (1) there is genetic variation in parthenogenetic populations of F. candida, and (2) this variation affects life-history and molecular endpoints relative to cadmium toxicity. This sheds new light on the sources of biological variability in test results, even when the test organisms are thought to be genetically homogeneous because of their parthenogenetic reproduction.