Transcriptional profiling of the soil invertebrate (Folsomia candida) in pentachlorophenol contaminated soil

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. Folsomia candida was exposed to pentachlorophenol spiked soil or untreated (reference/control) soil for 1, 2, and 7 days. For each time point 3 biological replicates were used, replicate samples consisted of total RNA extracted from 30 animals exposed in the same jar to either reference or pentachlorophenol spiked soil.