Transcriptome analysis of Eisenia fetida chronically exposed to benzo(a)pyrene

- Eisenia fetida chronically exposed in soil with 10 mg/kg of BaP.
- mRNA was isolated and sequenced from BaP exposed Eisenia fetida.
- The transcriptomes were in silico assembled from mRNA sequences.
- Genes involved in calcium homeostasis, apoptosis and lipid metabolism are altered.

Benzo(a)pyrene is a high molecular weight polycyclic aromatic hydrocarbon which is carcinogenic and widespread pollutant in the environment. It is essential to identify the presence of this chemical in soil as it is toxic to biota including humans. Eisenia fetida is a sentinel organism in soil which can be used to diagnose the health of the soil. In order to identify potential molecular markers from Eisenia fetida to diagnose the presence of benzo(a) pyrene in soil, we exposed the organism to sub-lethal (10mg Kg−1) concentrations for a period of eight months and carried out transcriptome analysis. From the transcriptome, we have identified differentially expressed genes. Results showed that benzo(a)pyrene has altered the expression of calcium binding and calcium homeostasis, apoptotic process, cytoskeletal proteins, protein transport, nucleotide binding, lipid metabolism, peripheral neuronal development, cell division, wound healing and processing genes at transcription level. Several of the genes we reported here were not reported earlier. The highly up regulated and down regulated genes could be used as a molecular marker to diagnose the presence of benzo(a)pyrene in the soil.

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