title: Transcriptomics reveals extensive inducible biotransformation in the soil-dwelling invertebrate Folsomia candida exposed to phenanthrene.
abstract: BACKGROUND
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: VU University Amsterdam, Institute of Ecological Science, Department of Animal Ecology, 1081 HV, Amsterdam, The Netherlands. benjamin.nota@gmail.com
authors.forename: Benjamin
authors.initials: B
authors.lastname: Nota
authors.forename: Mirte
authors.initials: M
authors.lastname: Bosse
authors.forename: Bauke
authors.initials: B
authors.lastname: Ylstra
authors.forename: Nico M
authors.initials: NM
authors.lastname: van Straalen
authors.forename: Dick
authors.initials: D
authors.lastname: Roelofs
mesh_terms: D000818:Animals; D001181:Arthropods / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D001711:Biotransformation; D002104:Cadmium / Q000633:toxicity; D020869:Gene Expression Profiling; D020411:Oligonucleotide Array Sequence Analysis; D010616:Phenanthrenes / Q000378:metabolism / Q000633:toxicity*; D012313:RNA / Q000235:genetics; D012098:Reproduction / Q000187:drug effects; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D010616:Phenanthrenes; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; C031181:phenanthrene; D012313:RNA