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. A direct design was used where springtails were exposed to 3 field soils (2 polluted and 1 clean) and cadium and microarrays were directly contrased to those from animals exposed to clean LUFA2.2 soil. 4 biological replicates were used with each containing 25 grams of soil and 30 adult, randomly selected, age sychronized springtails
Project description:Pentachlorophenol (PCP) as a widely used pesticide is also considered to be an endocrine disruptor. Molecular effects of chemicals with endocrine disrupting potential on soil invertebrates are largely unknown. Collembola (Folsomia candida) has been used as a model organism in ecotoxicity and in this study we explored the transcriptional expression changes of Folsomia candida in response to PCP contamination. A total of 92 genes were significantly differentially expressed at all exposure time and majority of them were found to be down-regulated. In addition to the transcripts encoding cytochrome P450s and transferase enzymes, chitin-binding protein was also identified in the list of common differentially genes. Analyses of Gene Ontology (GO) annotation and enrichment revealed that cell cycle related transcripts were significantly induced by PCP, indicating it can stimulated the cell proliferation in springtail as reported in human breast cancer cells. We also observed enrichment of functional terms related to steroid receptor and particularly twenty significant differential expressed genes involved in Chitin metabolism in response to PCP exposure. Combined with the confirmation by qPCR, our results appears that the adverse effects on reproduction of springtails after exposure to PCP can be attributed to a chemical-induced delay in the molting cycle and molting associated genes may serve as possible biomarkers for toxicological effects. In general, analysis of changes in the gene expression profiles of springtails in response to PCP exposure is useful for obtaining information on endocrine disruptor exposure of soil invertebrate and may contribute to the classification and risk assessment of relative chemicals.
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:Genetic and molecular evidence to support the hypothesis that fungal secondary metabolites play a significant role in protecting the fungi against fungivory is scarce. We investigated the impact of fungal secondary metabolites on transcript regulation of stress related expressed sequence tags (ESTs) of the Collembola Folsomia candida feeding on mixed vs. single diets. Aspergillus nidulans wildtype (WT; Ascomycota) able to produce secondary metabolites including sterigmatocystin (ST) and a knockout mutant with reduced secondary metabolism (A. nidulans ΔLaeA) were combined with the high quality fungus Cladosporium cladosporioides as mixed diets or offered as single diets. We hypothesized that (i) A. nidulans WT triggers more genes associated with stress responses compared to the A. nidulans ΔlaeA strain with suppressed secondary metabolism, (ii) C. cladosporioides causes significantly different transcript regulation than the A. nidulans strains ΔlaeA and WT, and (iii) mixed diets will cause significantly different transcript expression levels than single diets. All three hypotheses are generally supported despite the fact that many functions of the affected ESTs are unknown. The results bring molecular evidence for the existence of a link between fungal secondary metabolites and responses in springtails supporting the hypothesis that fungal secondary metabolites act as a shield against fungivory.
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:Genetic and molecular evidence to support the hypothesis that fungal secondary metabolites play a significant role in protecting the fungi against fungivory is scarce. We investigated the impact of fungal secondary metabolites on transcript regulation of stress related expressed sequence tags (ESTs) of the Collembola Folsomia candida feeding on mixed vs. single diets. Aspergillus nidulans wildtype (WT; Ascomycota) able to produce secondary metabolites including sterigmatocystin (ST) and a knockout mutant with reduced secondary metabolism (A. nidulans ?LaeA) were combined with the high quality fungus Cladosporium cladosporioides as mixed diets or offered as single diets. We hypothesized that (i) A. nidulans WT triggers more genes associated with stress responses compared to the A. nidulans ?laeA strain with suppressed secondary metabolism, (ii) C. cladosporioides causes significantly different transcript regulation than the A. nidulans strains ?laeA and WT, and (iii) mixed diets will cause significantly different transcript expression levels than single diets. All three hypotheses are generally supported despite the fact that many functions of the affected ESTs are unknown. The results bring molecular evidence for the existence of a link between fungal secondary metabolites and responses in springtails supporting the hypothesis that fungal secondary metabolites act as a shield against fungivory. Twenty-three day old Folsomia candida were fed ad libitum for five days to fungal cuts respectively Cladosporium cladosporoides, Aspergillus nidulans WT, Aspergillus nidulans ?LaeA and two mixed diets of C.cladosporoides/A. nidulans WT (mix 1) and C. cladosporoides/A. nudlans ?LaeA (mix2) respectively. Four biological replicates were used for every treatment and a dye swap was used with the Cy3/Cy5 labels. This resulted in 20 samples which were analysed in 10 hybridisations executed in an interwoven loop design. The C. cladosporoides diet was used as the reference in the data analysis.