Project description:Folsomia candida (Collembola) is able to survive dryer conditions by absorbing water vapour from its surroundings. To unravel the genomic responses underlying this intriguing water-absorption mechanism, we exposed the species to 98.2% Relative Humidity (eight, 27, 53 and 174 hours respectively) and subjected it to microarray based transcription profiling.
Project description:The present invention relates to methods for determining soil quality, and especially soil pollution, using the invertebrate soil organism Folsomia candida also designated as springtail. Specifically, the present invention relates to a method for determining soil quality comprising: contacting Folsomia Candida with a soil sample to be analysed during a time period of 1 to 5 days; isolating said soil contacted Folsomia Candida; extracting RNA from said isolated soil contacted Folsomia Candida; determing a gene expression profile based on said extracted RNA using microarray technology; comparing said gene expression profile with a reference gene expression profile; and determing soil quality based expression level differences between said gene expression profile and said control expression profile.
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: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. Microarrays were used to examine two different exposure concentrations of phenanthrene, namely the EC10 (24.95 mg kg-1 soil) and EC50 (45.80 mg kg-1 soil) on reproduction of this springtail, which evoked 405 and 251 differentially expressed transcripts, respectively. Fifty transcripts were differential in response to either concentration. Many transcripts encoding xenobiotic detoxification and biotransformation enzymes (phases I, II, and III) were upregulated in response to either concentration. Furthermore, indications of general and oxidative stress were found in response to phenanthrene. Chitin metabolism appeared to be disrupted particularly at the low concentration, and protein translation appeared suppressed at the high concentration of phenanthrene; most likely in order to reallocate energy budgets for the detoxification process. Finally, an immune response was evoked especially in response to the high effect concentration, which was also described in a previous transcriptomic study using the same effect concentration (EC50) of cadmium. Our study provides new insights in the molecular mode of action of the important polluting class of polycyclic aromatic hydrocarbons in soil animals. Furthermore, we present a fast, sensitive, and specific soil toxicity test which enhances traditional tests and may help to improve current environmental risk assessments and monitoring of potentially polluted sites.
Project description:Folsomia candida (Collembola) is able to survive dryer conditions by absorbing water vapour from its surroundings. To unravel the genomic responses underlying this intriguing water-absorption mechanism, we exposed the species to 98.2% Relative Humidity (eight, 27, 53 and 174 hours respectively) and subjected it to microarray based transcription profiling. About twenty-five 25-27 day old animals were placed in plastic containers that had a Relative Humidity of 98.2% (desiccated groups; n=16) or 100% RH (reference groups; n=16). After 8, 27, 53 and 174 hours four reference and four desiccation treated groups were snap-frozen (in liquid nitrogen) and stored at â80 °C until further analysis. Total RNA was obtained for each of the 32 samples. 500ng total RNA was labelled with the Agilent Low-Input Fluorescent Linear Amplification Kit. A pair-wise reference design was applied, implying that samples originating from desiccated groups were hybridized onto arrays with samples from reference groups that were exposed for the same duration; 8, 27, 53 or 174 hours). Dyes were swapped over the biological replicates.